Worldwide prevalence of adverse pregnancy outcomes among singleton pregnancies after in vitro fertilization/intracytoplasmic sperm injection: a systematic review and meta-analysis

Pregnancy outcomes in women with Celiac disease in Northeast Iran: a regional retrospective cohort study

PURPOSE

To investigate the odds and associations of pregnancy outcomes with exposure to biopsy-confirmed celiac disease (CD) in Northeast Iran.

METHODS

In this regional retrospective cohort study, pregnancy records of all women with celiac disease who visited Celiac Disease Clinic of Imam-Reza Hospital from 2017 to 2023 (exposed group) and a sample of women without CD (unexposed group) were extracted using the Electronic Health Record of Mashhad University of Medical Sciences called "Sina". The unexposed group was randomly selected of the database and matched to exposed group on age, location of residence, socioeconomic factors. Our exclusion criteria included age ≥ 45, presence of concomitant disorders, history of non-obstetric uterine surgery, induction of pregnancy through assisted reproductive technology, and any concurrently ongoing pregnancy at the time of study. Pregnancy outcomes evaluated in this study included normal delivery, miscarriage, preterm labor, preeclampsia, and stillbirth. Adjusted odds ratios were calculated using logistic regression adjusted for confounders.

RESULTS

Ninety pregnancy records of women with CD and 270 pregnancies of women without CD were included in this study. Low neonatal birthweight (i.e. under 2500 g) had no significant association with CD (aOR = 0.99, 95% CI = 0.92-1.06), as well as postpartum hemorrhage (aOR = 1.12, 95%CI = 0.91-1.38), fetal anomaly (aOR = 0.89, 95%CI = 0.69-1.15), miscarriage (aOR = 1.00, 95%CI = 0.91-1.10), ectopic pregnancy (aOR = 0.94, 95%CI = 0.73-1.20), preterm labor (aOR = 1.00, 95%CI = 0.92-1.10), gestational diabetes mellitus (aOR = 1.07, 95%CI = 0.98-1.16), gestational hypertension (aOR = 0.99, 95%CI = 0.89-1.11), and gestation hypothyroidism (aOR = 0.95, 95%CI = 0.82-1.11). However, we found significantly lower odds of preeclampsia in pregnancies affected by CD (aOR = 0.83, 95%CI = 0.69-0.99).

CONCLUSION

Celiac disease was not associated with increased odds of low neonatal birthweight, postpartum hemorrhage, fetal anomaly, miscarriage, ectopic pregnancy, preterm labor, gestational diabetes mellitus, gestational hypertension and gestational hypothyroidism. Preeclampsia had significantly lower odds in pregnancies affected with CD.

A comparison of pregnancy outcomes and congenital malformations in offspring between patients undergoing intracytoplasmic sperm injection and conventional in vitro fertilization: a retrospective cohort study

OBJECTIVE

To explore whether intracytoplasmic sperm injection (ICSI) would increase the malformation risk in fetuses and live births compared with conventional in vitro fertilization (IVF).

DESIGN

Retrospective cohort study.

PATIENT(S)

Data were collected from couples who underwent conventional IVF or ICSI from January 2009 to December 2019 at the Center for Reproductive Medicine of Peking University Third Hospital in the People's Republic of China. A total of 46,167 conventional IVF fresh transfer cycles and 33,247 ICSI fresh transfer cycles were included.

INTERVENTION(S)

Intracytoplasmic sperm injection and conventional IVF.

MAIN OUTCOME MEASURE(S)

The primary outcomes were congenital abnormalities in live births. The secondary outcomes included the pregnancy outcomes, the malformations among the miscarriages, specific types of malformations in live births, birth weight, and sex.

RESULT(S)

The rates of congenital malformations in conventional IVF and ICSI were 5.44‰ and 5.78‰, respectively. There was no statistically significant difference between the two groups, as indicated by the adjusted odds ratio of 1.098 (95% confidence interval 0.787, 1.532). The rates of specific malformations were comparable between ICSI and IVF. Additionally, no discernible disparities were noted in pregnancy outcomes, the malformations among the miscarriages,birth weight between the two groups.

CONCLUSION

Our study suggested the safety of ICSI and provided novel evidence by comparing pregnancy outcomes and congenital malformations in offspring between patients undergoing conventional IVF and ICSI.

Obstetric and perinatal outcomes in women with previous breast cancer: a nationwide study of singleton births 1973-2017

STUDY QUESTION

What are the obstetric and perinatal outcomes in births to breast cancer survivors compared to women without previous breast cancer?

SUMMARY ANSWER

Women who conceived during the first 2 years following a breast cancer diagnosis had a higher risk for preterm birth, induced delivery, and cesarean section, while no increased risks were observed in births conceived later than 2 years after a breast cancer diagnosis.

WHAT IS KNOWN ALREADY

A recent meta-analysis found higher risks of cesarean section, preterm birth, low birthweight, and small for gestational age in pregnancies among breast cancer survivors. Less is known about rarer outcomes such as pre-eclampsia or congenital malformations.

STUDY DESIGN SIZE DURATION

We conducted a population-based matched cohort study including all breast cancer survivors who gave birth to singletons 1973-2017 in Sweden, identified through linkage between the Swedish Cancer Register, the Medical Birth Register, and the National Quality Register for Breast Cancer.

PARTICIPANTS/MATERIALS SETTINGS METHODS

Each birth following breast cancer (n = 926) was matched by maternal age at delivery, parity, and calendar year at delivery to 100 births in a comparator cohort of women (n = 92 490). Conditional logistic and multinomial regression models estimated relative risks (RR) with 95% CI. Subgroup analyses by time since diagnosis and type of treatment were performed.

MAIN RESULTS AND THE ROLE OF CHANCE

Previous breast cancer was associated with higher risks of induced delivery (RR; 1.3, 1.0-1.6), very preterm birth (RR; 1.8, 1.1-3.0), and planned preterm birth (RR; 1.6, 1.0-2.4). Women who conceived within 1 year after breast cancer diagnosis had higher risks of cesarean section (RR; 1.7, 1.0-2.7), very preterm birth (RR; 5.3, 1.9-14.8), and low birthweight (RR; 2.7, 1.4-5.2), while the risks of induced delivery (RR; 1.8, 1.1-2.9), moderately preterm birth (RR; 2.1, 1.2-3.7), and planned preterm birth (RR; 2.5, 1.1-5.7) were higher in women who conceived during the second year after diagnosis. Women who conceived later than 2 years after breast cancer diagnosis had similar obstetric risks to their comparators.

LIMITATIONS REASONS FOR CAUTION

As information on the end date of treatment was unavailable, the time between the date of diagnosis and conception was used as a proxy, which does not fully capture the effect of time since end of treatment. In addition, treatments and clinical recommendations have changed over the long study period, which may impact childbearing patterns in breast cancer survivors.

WIDER IMPLICATIONS OF THE FINDINGS

Risks of adverse obstetric outcomes in breast cancer survivors were confined to births conceived within 2 years of diagnosis. As family building holds significance for numerous young breast cancer patients, these findings are particularly important to inform both breast cancer survivors and clinicians about future reproductive outcomes.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by the Swedish Cancer Society (grant number 22-2044 Pj A.L.V.J.), Karolinska Institutet Foundations (grant number: 2022-01696 F.E.L., 2022-01559 A.L.V.J.), and the Swedish Research Council (grant number: 2021-01657 A.L.V.J.). K.A.R.-W. is supported by grants from the Swedish Cancer Society (20 0170 F) and the Radiumhemmets Research Foundations for clinical researchers 2020-2026. The authors declare that they have no conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A.

Maternal and obstetric outcomes following the transfer of embryos warmed with fatty acid-supplemented solutions

BACKGROUND

Vitrification procedures decrease intracytoplasmic lipid content and impair developmental competence. Adding fatty acids (FAs) to the warming solution has been shown to recover the lipid content of the cytoplasm and improve developmental competence and pregnancy outcomes. However, the influence of the FA supplementation on live birth rates after embryo transfers and perinatal outcomes remains unknown. In the present study, we examined the influence of FA-supplemented warming solutions on live birth rates, pregnancy complications, and neonatal outcomes after single vitrified-warmed cleavage-stage embryo transfers (SVCTs).

METHODS

The clinical records of 701 treatment cycles in 701 women who underwent SVCTs were retrospectively analyzed. Vitrified embryos were warmed using solutions (from April 2022 to June 2022, control group) or FA-supplemented solutions (from July 2022 to September 2022, FA group). The live birth rate, pregnancy complications, and perinatal outcomes were compared between the control and FA groups.

RESULTS

The live birth rate per transfer was significantly higher in the FA group than in the control group. Multivariate logistic regression analysis further demonstrated a higher probability of live births in the FA group than in the control group. Miscarriage rates, the incidence and types of pregnancy complications, the cesarean section rate, gestational age, incidence of preterm delivery, birth length and weight, incidence of low birth weight, infant sex, and incidence of birth defects were all comparable between the control and FA groups. Multivariate logistic regression analysis further demonstrated no adverse effects of FA-supplemented warming solutions.

CONCLUSIONS

FA-supplemented warming solutions improved live birth rates after SVCTs without exerting any adverse effects on maternal and obstetric outcomes. Therefore, FA-supplemented solutions can be considered safe and effective for improving clinical outcomes and reducing patient burden.

Children born to subfertile couples, how are they doing? Evidence from research

More than 10 million children have been born with assisted reproductive technology (ART) as we begin to enter the third generation of individuals conceived by ART. Here we summarise key messages from an enlarging body of literature regarding their health. Earlier research had pointed towards increases in perinatal, neonatal and neurological risks, such as preterm birth, low birth weight, congenital malformations and cerebral palsy. Many of these risks have continued to persist in most recent work but have shown reduction. Newer research proposes long-term cardiometabolic and endocrine concerns. Fortunately, most reports conclude there is little or no risk of increased childhood malignancy or abnormal neurodevelopment. Moving forward, new research may benefit from changes in comparator groups and a better understanding of infertility per se in ART, and the confounding role it probably plays in many of the known risk associations, to reliably scan the horizon for health threats for individuals born after ART.

Deprived areas and adverse perinatal outcome: a systematic review

PURPOSE

This systematic review aimed to assess if women living in deprived areas have worse perinatal outcomes than those residing in high-income areas.

METHODS

Datasets of PubMed, ScienceDirect, CENTRAL, Embase, and Google Scholar were searched for studies comparing perinatal outcomes (preterm birth, small-for-gestational age, and stillbirth) in deprived and non-deprive areas.

RESULTS

A total of 46 studies were included. The systematic review of the literature revealed a higher risk for adverse perinatal outcomes such as preterm birth, small for gestational age, and stillbirth in deprived areas.

CONCLUSION

Deprived areas are associated with adverse perinatal outcomes. More multifactorial studies are needed to assess the weight of each factor that composes the socioeconomic gradient of health in adverse perinatal outcomes.

Association Between Assisted Reproductive Technology and Cerebral Palsy: A Meta-Analysis

BACKGROUND

Since 1978 many children are born thanks to assisted reproductive technology (ART). However, the long-term effects of these therapies are still not fully known. Our objective is to evaluate the risk of cerebral palsy (CP) after ART compared with that in those spontaneously conceived (SC) and to examine this risk in single, multiple, and preterm births and the evolution of the risk over the years.

METHODS

PubMed, Embase, and Web of Science databases were searched until December 2022. Studies were included if they studied CP cases in children born through ART. 16 studies were finally selected. Quality of studies was assessed using Newcastle Ottawa Scale. Pooled OR was estimated by weighting individual OR/RR by the inverse of their variance. A random-effect model was applied. To assess the causes of heterogeneity, we performed meta-regression analyses.

RESULTS

A significantly high risk of CP was found (OR = 1.27; 95% CI 1.12 to 1.43) in children born through ART compared with those SC. This risk increased in singletons (OR = 1.48; 95% CI 1.23 to 1.79) but disappeared in multiple (OR = 1.05; 95% CI 0.93 to 1.18) and preterm births (OR = 1.09; 95% CI 0.87 to 1.37). We found a higher risk of CP in children born before the year 2000 (OR = 3.40; 95% CI 2.49 to 4.63).

CONCLUSIONS

ARTs slightly increase the risk of CP once the effect of multiple gestation is controlled. Further studies are needed to clarify whether the techniques themselves, fertility problems, or associated maternal comorbidities are responsible for this risk.

Medically assisted reproduction and mental health in adolescence: evidence from the UK Millennium Cohort Study

BACKGROUND

The number and proportion of children conceived through medically assisted reproduction (MAR) is steadily increasing yet the evidence on their mental health in adolescence is inconclusive. Two main mechanisms with opposite effects can explain differences in mental health outcomes by conception mode: while more advantaged parental characteristics could positively influence it, higher parental stress could have a negative influence.

METHODS

Linear and logistic estimations on a longitudinal population-based birth cohort study of 9,897 individuals to investigate whether adolescents conceived through MAR are more likely than naturally conceived (NC) children to experience mental health problems at age 17, as reported by adolescents themselves and their parents. We test whether this association is confounded and/or mediated by parental background characteristics collected when the cohort member was around 9 months old (maternal age, maternal education level, ethnicity, income quintile), family structure variables measured in adolescence (number of siblings in the household at age 15, parental household structure at age 14) or maternal distress at age 14.

RESULTS

Children conceived naturally and through MAR self-reported similar mental health outcomes. The only differences between MAR and NC adolescents are in the parental reports, with parents who conceived through MAR reporting their children had 3.82 (95% CI: 1.140 to 11.54) and 2.35 (95% CI: 1.145 to 4.838) higher odds of falling within the high category of SDQ total difficulties and emotional symptoms scales, respectively. The results did not change on adjustment for mediators, such as maternal distress, number of siblings in the household and parental household structure.

CONCLUSIONS

The results reveal a lack of or small differences in MAR adolescents' mental health outcomes compared to children who were conceived naturally. While the results based on the parental reports could suggest that MAR adolescents are at higher risk of suffering from mental health problems, the differences are small and not supported by adolescents' own reports. The difference between MAR and NC adolescent's parental report might reflect differences in parental concern, their relationship or closeness and can help to reconcile the mixed findings of previous studies.

Female obesity increases the risk of preterm birth of single frozen-thawed euploid embryos: a retrospective cohort study

INTRODUCTION

Obesity has been associated with an increased risk of reproductive failure, especially preterm birth. As preimplantation genetic testing for aneuploidies (PGT-A) is increasingly used worldwide, however, it is still unclear whether body mass index (BMI) has an effect on the preterm birth rate in patients undergoing in vitro fertilization (IVF) with PGT-A when transferring a single euploid blastocyst.

MATERIALS AND METHODS

This retrospective, single-center cohort study included 851 women who underwent the first cycle of frozen-thawed single euploid blastocyst transfer with PGT-A between 2015 and 2020. The primary outcome was the preterm birth rate. Secondary outcomes were clinical pregnancy, miscarriage, ectopic pregnancy, pregnancy complications, and live birth.

RESULTS

Patients were grouped by World Health Organization (WHO) BMI class: underweight (<18.5, n = 81), normal weight (18.5-24.9, n = 637), overweight (25-30, n = 108), and obese (≥30, n = 25). There was no difference in the clinical pregnancy, miscarriage, ectopic pregnancy, pregnancy complication, and live birth by BMI category. In multivariate logistic regression analysis, preterm birth rates were significantly higher in women with overweight (adjusted odds ratio [aOR] 3.18; 95% confidence interval [CI], 1.29-7.80, p = .012) and obese (aOR 1.49; 95% CI, 1.03-12.78, p = .027) compared with the normal weight reference group.

CONCLUSION

Women with obesity experience a higher rate of preterm birth after euploid embryo transfer than women with a normal weight, suggesting that the negative impact of obesity on IVF and clinical outcomes may be related to other mechanisms than aneuploidy.

Children born after assisted reproduction more commonly carry a mitochondrial genotype associating with low birthweight

Children conceived through assisted reproductive technologies (ART) have an elevated risk of lower birthweight, yet the underlying cause remains unclear. Our study explores mitochondrial DNA (mtDNA) variants as contributors to birthweight differences by impacting mitochondrial function during prenatal development. We deep-sequenced the mtDNA of 451 ART and spontaneously conceived (SC) individuals, 157 mother-child pairs and 113 individual oocytes from either natural menstrual cycles or after ovarian stimulation (OS) and find that ART individuals carried a different mtDNA genotype than SC individuals, with more de novo non-synonymous variants. These variants, along with rRNA variants, correlate with lower birthweight percentiles, independent of conception mode. Their higher occurrence in ART individuals stems from de novo mutagenesis associated with maternal aging and OS-induced oocyte cohort size. Future research will establish the long-term health consequences of these changes and how these findings will impact the clinical practice and patient counselling in the future.

Systematic review and meta-analysis of reproductive outcomes after high-intensity focused ultrasound (HIFU) treatment of adenomyosis

High-intensity focused ultrasound (HIFU) has emerged as a promising uterus-sparing and possibly fertility-sparing treatment modality for women with adenomyosis, especially those who desire to conceive. We conducted this systematic review and performed a meta-analysis on clinical studies aimed to improve reproduction in women with adenomyosis. After extensive search of PubMed and CNKI, we identified 10 studies published in English and Chinese involving a total of 557 patients with adenomyosis who desired to conceive after HIFU treatment. We found a pooled estimate of pregnancy rate of 53.4% and of the live birth rate of 35.2%, and there was a substantial heterogeneity among these studies. While there is a potential for HIFU treatment to improve fertility for patients with adenomyosis who desired to conceive, such evidence is very weak as of now. Comparative studies with much higher methodological rigor, preferably randomized clinical trials, are badly needed to further illuminate this issue.

Pregnancies through oocyte donation. A mini review of pathways involved in placental dysfunction

Pregnancies resulting from assisted reproductive techniques (ART) are increasingly prevalent worldwide. While most pregnancies conceived through in-vitro fertilization (IVF) progress without complications, mounting evidence suggests that these pregnancies are at a heightened risk of adverse perinatal outcomes. Specifically, IVF pregnancies involving oocyte donation have garnered attention due to numerous reports indicating an elevated risk profile for pregnancy-related complications within this subgroup of patients. The precise mechanisms contributing to this increased risk of complications remain incompletely understood. Nonetheless, it is likely that they are mediated by an abnormal immune response at the fetal-maternal interface. Additionally, these outcomes may be influenced by baseline patient characteristics, such as the etiology of infertility, absence of corpus luteum, and variations in endometrial preparation protocols, among other factors. This review aims to succinctly summarize the most widely accepted mechanisms that potentially contribute to the onset of placental dysfunction in pregnancies conceived through oocyte donation.

Investigating the Association of Assisted Reproduction Techniques and Adverse Perinatal Outcomes

BACKGROUND

Infertility affects about 80 million individuals worldwide and 10-15% of couples at reproductive age will seek medical assistance. There is increasing evidence that pregnancies after Assisted Reproduction Techniques (ART) are associated with pre-term birth, low birthweight, congenital defects, and increased mortality rates. The aim of this review is to assess all the published literature and provide an updated review on the effect of assisted conception and perinatal and neonatal outcomes.

METHODS

Comprehensive research on Pubmed/Medline, Scopus, and Google scholar electronic databases was conducted from July 2023 up to September 2023, using the terms assisted reproductive techniques, ART, in vitro fertilization, IVF, intracytoplasmic sperm injection, ICSI, preterm birth, PTB, low birth weight, LBW, chromosomal defects, congenital defects, and hypospadias. In total, 87 full text articles were retrieved and after a careful evaluation, 31 studies were selected for data extraction.

RESULTS

Our review demonstrated a higher risk of congenital and chromosomal defects, and a higher incidence of male genital tract defects and heart defects in ART pregnancies. Regarding pre-term birth, our results were contradictory.

CONCLUSIONS

Although assisted reproduction techniques are associated with increased risks, they are safe regarding perinatal outcomes and couples should not be discouraged from utilizing them. Our results aim to alert clinicians to these specific outcomes and offer more personalized care and counseling to infertile couples and their children.

Antenatal fetal growth patterns in uncomplicated pregnancies according to mode of conception and placental location

Newborns resulting from in-vitro fertilisation (IVF) had a significantly (P= 0.002) higher birthweight centile than those resulting from spontaneous conception (SC) but no significant changes were found in ultrasound estimated fetal weight (EFW) centile between 20-22 and 32-34 weeks between the IVF and SC groups. When stratified for the IVF methods used, significant (P = 0.02) fastest in-utero fetal growth (mean increase in centile of 5 between 2nd to 3rd trimester) was observed in the frozen embryo transfer (FET) subgroup compared to SC, and to IVF pregnancies resulting from fresh blastocyst transfer (FBT) or from oocyte donation (OD). Low placentation was significantly (P < 0.001) more common in the IVF group than in the SC group but was not associated with a change in growth pattern suggesting that fetal growth in-utero is independent of placental location but may be influenced by embryo freezing.

No major differences in perinatal and maternal outcomes between uninterrupted embryo culture in time-lapse system and conventional embryo culture

STUDY QUESTION

Is embryo culture in a closed time-lapse system associated with any differences in perinatal and maternal outcomes in comparison to conventional culture and spontaneous conception?

SUMMARY ANSWER

There were no significant differences between time-lapse and conventional embryo culture in preterm birth (PTB, <37 weeks), low birth weight (LBW, >2500 g) and hypertensive disorders of pregnancy for singleton deliveries, the primary outcomes of this study.

WHAT IS KNOWN ALREADY

Evidence from prospective trials evaluating the safety of time-lapse incubation for clinical use show similar embryo development rates, implantation rates, and ongoing pregnancy and live birth rates when compared to conventional incubation. Few studies have investigated if uninterrupted culture can alter risks of adverse perinatal outcomes presently associated with IVF when compared to conventional culture and spontaneous conceptions.

STUDY DESIGN, SIZE, DURATION

This study is a Swedish population-based retrospective registry study, including 7379 singleton deliveries after fresh embryo transfer between 2013 and 2018 from selected IVF clinics. Perinatal outcomes of singletons born from time-lapse-cultured embryos were compared to singletons from embryos cultured in conventional incubators and 71 300 singletons from spontaneous conceptions. Main perinatal outcomes included PTB and LBW. Main maternal outcomes included hypertensive disorders of pregnancy (pregnancy hypertension and preeclampsia).

PARTICIPANTS/MATERIALS, SETTING, METHODS

From nine IVF clinics, 2683 singletons born after fresh embryo transfer in a time-lapse system were compared to 4696 singletons born after culture in a conventional incubator and 71 300 singletons born after spontaneous conception matched for year of birth, parity, and maternal age. Patient and treatment characteristics from IVF deliveries were cross-linked with the Swedish Medical Birth Register, Register of Birth Defects, National Patient Register and Statistics Sweden. Children born after sperm and oocyte donation cycles and after Preimplantation Genetic testing cycles were excluded. Odds ratio (OR) and adjusted OR were calculated, adjusting for relevant confounders.

MAIN RESULTS AND THE ROLE OF CHANCE

In the adjusted analyses, no significant differences were found for risk of PTB (adjusted OR 1.11, 95% CI 0.87-1.41) and LBW (adjusted OR 0.86, 95% CI 0.66-1.14) or hypertensive disorders of pregnancy; preeclampsia and hypertension (adjusted OR 0.99, 95% CI 0.67-1.45 and adjusted OR 0.98, 95% CI 0.62-1.53, respectively) between time-lapse and conventional incubation systems. A significantly increased risk of PTB (adjusted OR 1.31, 95% CI 1.08-1.60) and LBW (adjusted OR 1.36, 95% CI 1.08-1.72) was found for singletons born after time-lapse incubation compared to singletons born after spontaneous conceptions. In addition, a lower risk for pregnancy hypertension (adjusted OR 0.72 95% CI 0.53-0.99) but no significant difference for preeclampsia (adjusted OR 0.87, 95% CI 0.68-1.12) was found compared to spontaneous conceptions. Subgroup analyses showed that some risks were related to the day of embryo transfer, with more adverse outcomes after blastocyst transfer in comparison to cleavage stage transfer.

LIMITATIONS, REASONS FOR CAUTION

This study is retrospective in design and different clinical strategies may have been used to select specific patient groups for time-lapse versus conventional incubation. The number of patients is limited and larger datasets are required to obtain more precise estimates and adjust for possible effect of additional embryo culture variables.

WIDER IMPLICATIONS OF THE FINDINGS

Embryo culture in time-lapse systems is not associated with major differences in perinatal and maternal outcomes, compared to conventional embryo culture, suggesting that this technology is an acceptable alternative for embryo incubation.

STUDY FUNDING/COMPETING INTEREST(S)

The study was financed by a research grant from Gedeon Richter. There are no conflicts of interest for all authors to declare.

TRIAL REGISTRATION NUMBER

N/A.

Comparing the occurrence rate of gestational hypertension during pregnancy with frozen embryo transfer and natural pregnancy

Introduction

Recent researches have indicated that pregnancies with frozen embryo transfer are associated with the increment of risk of maternal and neonatal complications, especially hypertension during pregnancy. The present study aimed to compare the occurrence rate of gestational hypertension in pregnancy with frozen embryo transfer and normal pregnancy.

Materials and Methods

This research, as a retrospective cross-sectional study, was performed on pregnant women with frozen embryo transfer (n = 97) and women with normal pregnancies (n = 164) referring to medical centers under the supervision of Ahvaz University of Medical Sciences in 2021. Women aged 18-35 were included in the study after week 20th of pregnancy. Maternal and neonatal outcomes including hypertensive disorders of pregnancy (including gestational hypertension and preeclampsia), preterm birth (before the week 37th), low birth weight (lower than 2500 g), neonatal asphyxia (Apgar score >7 in minute 5th), intrauterine growth restriction (IUGR) and bleeding in the first trimester of pregnancy were evaluated. The association between frozen embryo transfer and pregnancy outcomes was evaluated using multiple logistic regressions.

Results

The findings of this study indicated that pregnancy hypertension was observed in 23 people (23.7%) from the frozen embryo transfer group vs. 18 people (11.0%) from the normal pregnancy group (P = 0.006). Frozen embryo transfer pregnancy has a higher risk of gestational hypertension (OR = 2.521, 95% CI: 1.281-4.962; P = 0.007), preterm birth (OR = 2.264, 95% CI: 1.335-3.840; P = 0.002), and low birth weight (OR = 2.017, 95% CI: 1.178-3.455; P = 0.011). However, the incidence of birth asphyxia (P = 0.850), intrauterine growth restriction (P = 0.068), first-trimester bleeding (P = 0.809), and placenta accreta (P = 0.143) did not show a significant difference between two types of normal pregnancy and frozen embryo transfer pregnancy.

Conclusion

Frozen embryo transfer pregnancy was associated with a higher risk of maternal and neonatal complications, hypertension, preterm birth, and low birth weight compared to natural and spontaneous pregnancies.

Pregnancy Outcomes in Patients with Primary Sjögren's Syndrome Undergoing Assisted Reproductive Therapy: A Multi-center Retrospective Study

INTRODUCTION

The aim of this work was to investigate the pregnancy outcomes in infertile patients with primary Sjögren's syndrome (pSS) undergoing assisted reproductive therapy (ART).

METHODS

A multi-center retrospective study was performed in pregnant women with pSS and ART from five tertiary hospitals from Guangdong Province from 2013 to 2022. Natural planned pregnancy in pSS and healthy people undergoing ART were selected as controls. Pregnancy outcomes were collected from medical records and compared among groups.

RESULTS

Twenty-four pregnancies in pSS with ART, 70 natural planned pregnancies in pSS, and 96 pregnancies in healthy people with ART were analyzed. More than half of the pSS mothers undergoing ART have a past history of adverse pregnancy and spontaneous abortion was the most common (10/24, 41.7%). Primary infertility (25.0%) and recurrent spontaneous abortion (16.7%) were the leading causes of infertility in pSS. The major maternal adverse pregnancy outcome (APO) in pSS patients with ART was premature delivery (11/24, 45.8%), likely attributed to twin gestation (4/11, 36.4%) and fetal distress (3/11, 27.3%). Twenty-seven live infants were born from 22 successful deliveries. The live birth rate was 93.1% (27/29). The average delivery time was 36.1 ± 3.3 weeks of gestation. The average birthweight was 2434.4 ± 722.1 g, compared with 2844.9 g in natural planned pregnancy in pSS, and 3072.1 g from healthy mothers with ART (P < 0.001). Seven (25.9%) low-birthweight (LBW) infants were born, and the incidence was comparable to the other two groups (22.2% in natural pregnancy, 13.0% in healthy people, P = 0.09). No infants developed congenital heart block (CHB).

CONCLUSIONS

ART is an effective method for infertility in patients with pSS. Premature delivery is the leading maternal APOs. The incidence of fetal APOs does not increase, while birthweight is lower in offspring from pSS mothers with ART.

Elevated antimüllerian hormone levels are not associated with preterm delivery after in vitro fertilization or ovulation induction

OBJECTIVE

To investigate the association between antimüllerian hormone (AMH) and preterm birth risk in a larger cohort of patients who underwent either in vitro fertilization or ovulation induction with intrauterine insemination at a US academic fertility center.

DESIGN

Retrospective cohort study.

SETTING

Single academic fertility center.

PATIENT(S)

Live singleton births from patients who underwent in vitro fertilization or ovulation induction between 2016 and 2020 at a single academic fertility center were included in this study. Patients were excluded if they had a missing prepregnancy AMH level, a pregnancy using donor oocytes or a gestational carrier, multiple gestations, a delivery before 20 weeks gestation, or a cerclage in place.

INTERVENTION(S)

AMH level.

MAIN OUTCOME MEASURE(S)

The primary outcome was the proportion of preterm delivery. Secondary outcomes included the rate of pregnancy-induced hypertension, gestational diabetes, and small for gestational age.

RESULT(S)

In the entire cohort (n = 875), 8.4% of deliveries were preterm. The mean AMH values were similar between those with term and preterm births (3.9 vs. 4.2 ng/mL). Similar proportions of patients with term and preterm deliveries had AMH levels greater than the 75th percentile (25% vs. 21%). The odds of preterm birth were similar by AMH quartile after adjusting for the history of preterm birth. Similarly, in the polycystic ovary syndrome (PCOS) cohort, there was no difference between mean AMH values of term and preterm births (n = 139, 9.6 vs. 10.0 ng/mL). The proportions of patients with PCOS with AMH levels greater than the 75th percentile were similar between those with term and preterm deliveries (25% vs. 22%). The odds of preterm birth were similar by the AMH quartile after adjusting for the history of preterm birth.

CONCLUSION(S)

Elevated AMH levels were not associated with an increased risk of preterm birth in patients who conceived after in vitro fertilization and ovulation induction, including patients with PCOS. Although studies suggest that AMH levels may help stratify the risk of preterm birth in this population, our findings indicate that further studies are needed before clinical application.

Elevated Sperm DNA Damage in IVF-ICSI Treatments Is Not Related to Pregnancy Complications and Adverse Neonatal Outcomes

This multicenter retrospective cohort study assesses the effect of high paternal DNA fragmentation on the well-being of the woman during pregnancy and the health of the newborn delivered. It was performed with clinical data from 488 couples who had a delivery of at least one newborn between January 2000 and March 2019 (243 used autologous oocytes and 245 utilized donated oocytes). Couples were categorized according to sperm DNA fragmentation (SDF) level as ≤15% or >15%, measured by TUNEL assay. Pregnancy, delivery, and neonatal outcomes were assessed. In singleton pregnancies from autologous cycles, a higher but non-significant incidence of pre-eclampsia, threatened preterm labor, and premature rupture of membranes was found in pregnant women from the >15%SDF group. Additionally, a higher proportion of children were born with low birth weight, although the difference was not statistically significant. After adjusting for potential confounders, these couples had lower odds of having a female neonate (AOR = 0.35 (0.1-0.9), p = 0.04). Regarding couples using donor's oocytes, pregnancy and neonatal outcomes were comparable between groups, although the incidence of induced vaginal labor was significantly higher in the >15% SDF group (OR = 7.4 (1.2-46.7), p = 0.02). Adjusted analysis revealed no significant association of elevated SDF with adverse events. In multiple deliveries from cycles using both types of oocytes, the obstetric and neonatal outcomes were found to be similar between groups. In conclusion, the presence of an elevated SDF does not contribute to the occurrence of clinically relevant adverse maternal events during pregnancies, nor does it increase the risk of worse neonatal outcomes in newborns. Nevertheless, a higher SDF seems to be related to a higher ratio of male livebirths.

Association between gestational weight gain and adverse neonatal outcomes in women conceiving with assisted reproductive technology: Evidence from the NVSS 2019-2021

OBJECTIVE

To evaluate the association between gestational weight gain (GWG) and adverse neonatal outcomes in women who conceived using assisted reproductive technology (ART).

METHODS

The National Vital Statistics System (NVSS) 2019-2021 provided data for this retrospective cohort study. Adverse neonatal outcomes included premature birth, small for gestational age (SGA), large for gestational age (LGA), macrosomia, low birth weight (LBW), and other abnormal conditions. Any adverse outcome was defined as at least one of the above six outcomes. Multivariate logistic regression analysis was employed to evaluate the associations between GWG and different outcomes, after adjusting for confounding factors. These associations were further assessed in subgroups of maternal age at delivery, paternal age at delivery, preconception body mass index (BMI), gestational age, maternal race, parity, gestational diabetes, and gestational hypertension.

RESULTS

Totally 108201 women were included, with 22282 in the insufficient GWG group, 38034 in the sufficient GWG group, and 47885 in the excessive GWG group. Women with insufficient GWG [odds ratios (OR) = 1.11, 95%CI: 1.07-1.16, P<0.001] and excessive GWG (OR = 1.14, 95%CI: 1.10-1.18, P<0.001) had significantly greater risks of any adverse outcome than those with sufficient GWG. In contrast to sufficient GWG, insufficient GWG was associated with significantly elevated risks of premature birth (OR = 1.42, 95%CI: 1.35-1.48, P<0.001), SGA (OR = 1.45, 95%CI: 1.37-1.53, P<0.001), LBW (OR = 1.47, 95%CI: 1.37-1.58, P<0.001), and other abnormal conditions (OR = 1.32, 95%CI: 1.27-1.39, P<0.001), and excessive GWG was associated with significantly lower risks of premature birth (OR = 0.86, 95%CI: 0.83-0.90, P<0.001), SGA (OR = 0.79, 95%CI: 0.75-0.83, P<0.001), LBW (OR = 0.85, 95%CI: 0.79-0.91, P<0.001), and other abnormal conditions (OR = 0.92, 95%CI: 0.88-0.96, P<0.001). Infants born to women with insufficient GWG had significantly decreased risks of LGA (OR = 0.71, 95%CI: 0.66-0.75, P<0.001) and macrosomia (OR = 0.68, 95%CI: 0.63-0.74, P<0.001), and infants born to women with excessive GWG had significantly increased risks of LGA (OR = 1.50, 95%CI: 1.44-1.56, P<0.001) and macrosomia (OR = 1.60, 95%CI: 1.51-1.69, P<0.001).

CONCLUSION

Insufficient GWG and excessive GWG were associated with increased risks of any adverse outcome than sufficient GWG in women who conceived with ART, indicating the applicability of recommended GWG by the Institute of Medicine (IOM) in this population.

Long-term outcomes for children conceived by assisted reproductive technology

Worldwide, more than 10 million children have been born after assisted reproduction technology (ART), comprising up to 7.9% of children born in Europe and up to 5.1 % of children born in the US in 2018. The short-term outcome for children born after ART is well-known from numerous publications, with higher rates of preterm birth and low birth weight in children born after fresh embryo transfer and higher rates of large for gestational age and high birth weight in children born after frozen embryo transfer compared with children born after spontaneous conception. Higher rates of birth defects in children born after ART have also been shown consistently over time. Studies on long-term health outcomes after ART are scarcer but suggest an increased risk of altered blood pressure and cardiovascular function in children born after ART. In this review, we summarize long-term health outcomes in children born after ART and discuss whether the increased health risks are associated with intrinsic maternal or paternal factors related to subfertility or ART treatments per se. Finally, we speculate where the future will bring us regarding ART treatment strategies and the safety of the mother and child.

The duration of estrogen treatment before progesterone application does not affect neonatal and perinatal outcomes in frozen embryo transfer cycles

Objective

To explore whether the duration of estrogen treatment before progesterone application affects neonatal and perinatal outcomes in artificial frozen embryo transfer (FET) cycles.

Methods

This was a retrospective cohort study. Patients who underwent FET via artificial cycles and delivered a singleton live birth between January 2015 and August 2019 were included in the analysis. According to the duration of estrogen treatment before progesterone application, we divided the cycles into four groups: ①≤12 days, ②13-15 days, ③16-19 days, and ④≥20 days. The '≤12 days group' was considered the reference group. The main outcome measures were preterm birth (PTB), small-for-gestational age (SGA), low birth weight (LBW), macrosomia, large-for-gestational age (LGA), gestational diabetes mellitus (GDM), gestational hypertension, premature rupture and placenta previa.

Results

Overall, 2010 FET cycles with singleton live births were included for analysis. Cycles were allocated to four groups according to the duration of estrogen treatment before progesterone application: ①≤12 days (n=372), ②13-15 days (n=745), ③16-19 days (n=654), ④≥20 days (n=239). The neonatal outcomes, including PTB, SGA, LBW, macrosomia and LGA, were comparable among the groups (P=0.328, P=0.390, P=0.551, P=0.565, P=0.358). The rates of gestational hypertension, premature rupture and placenta previa (P=0.676, P=0.662, P=0.211) were similar among the groups. The rates of GDM among the four groups were 4.0% (15/372), 6.7% (50/745), 6.4% (42/654), and 11.3% (27/239), with statistical significance (P=0.006). After multiple logistic regression analysis, the duration of estrogen treatment did not affect the rate of GDM or other outcomes.

Conclusion

The estrogen treatment duration before progesterone application does not affect neonatal and perinatal outcomes in single frozen blastocyst transfer cycles.

Assisted Reproductive Technology and Breech Delivery: A Nationwide Cohort Study in Singleton Pregnancies

Since essential factors have changed in recent years in assisted reproduction technologies (ARTs), this study reassessed the association between ART and breech presentation. We primarily aimed to estimate the correlation between ART and breech at delivery. Secondary purposes were to evaluate the correlation between other subfertility treatments (OSTs) and breech and to assess possible confounding factors and temporal trends. This study investigated the 31,692,729 live birth certificates from US states and territories in the 2009-2020 period. The inclusion criteria were singleton births reporting the method of conception and the presentation at delivery. The outcome was the breech presentation at delivery, while the primary exposure was ART, the secondary exposure was OST, and the potential confounding factors from the literature were considered. ART (OR 2.32 CI.95 2.23-2.41) and OST (OR 1.79 CI.95 1.71-1.87) were independent and significant risk factors for breech at delivery (p < 0.001). This study confirmed breech presentation risk factors maternal age, nulliparity, tobacco smoke, a previous cesarean delivery (CD), neonatal female sex, gestational age, and birth weight. Black race and Hispanic origin were verified to be protective factors. We found breech prevalence among ART and OST to be stable during the study period. Meanwhile, newborn birth weight was increased, and the gap between breech and other presentations in ART was reduced. Our results indicate that singleton pregnancies conceived by ART or OST were associated with a higher risk of breech at delivery. Well-known risk factors for the breech presentation were also confirmed. Some of these factors can be modified by implementing interventions to reduce their prevalence (e.g., tobacco smoke and previous CD).

Fetal Growth Velocity according to the Mode of Assisted Conception

INTRODUCTION

Pregnancies conceived through assisted reproductive techniques (ARTs) are on the rise worldwide and have been associated with a higher risk of placental-related disease in the third trimester.

METHODS

A cohort was created of singleton pregnancies after assisted reproduction, admitted at our institution for delivery, between January 2020 and August 2022. Fetal growth velocity from the second trimester to delivery was compared against a gestational-age-matched group of pregnancies spontaneously conceived according to the origin of the selected oocyte (i.e., autologous vs. donated).

RESULTS

125 singleton pregnancies conceived through ART were compared to 315 singleton spontaneous conceptions. Overall, after adjusting for possible confounders, multivariate analysis demonstrated that ART pregnancies had a significantly lower estimated fetal weight (EFW) z-velocity from the second trimester to delivery (adjusted mean difference = -0.002; p = 0.035) and a higher frequency of EFW z-velocity in the lowest decile (adjusted OR = 2.32 [95% CI, 1.15-4.68]). Also, when ART pregnancies were compared according to the type of oocyte, those conceived with donated oocytes showed a significantly lower EFW z-velocity from the second trimester to delivery (adjusted mean difference = -0.008; p = 0.001) and a higher frequency of EFW z-velocity in the lowest decile (adjusted OR = 5.33 [95% CI, 1.34-21.5]).

CONCLUSIONS

Pregnancies achieved through ART exhibit a pattern of lower growth velocity across the third trimester, especially those conceived with donated oocytes. The former represents a sub-group at the highest risk of placental dysfunction that may warrant closer follow-up.

Perinatal Outcome of Singletons Born after Using a Simplified Low-Cost IVF Culture System and All Singletons Born in Flanders (Belgium) between 2012 and 2020

BACKGROUND

We developed a simplified IVF culture system (SCS) which has proven to be effective and safe in a selected IVF cohort.

METHODS

Preterm birth (PTB) and low birth weight (LBW) of 175 singletons born after using the SCS, 104 after fresh embryo transfer (ET), and 71 after frozen embryo transfer, were compared with all singletons born in Flanders between 2012 and 2020 conceived after natural conception, ovarian stimulation (OS), and assisted reproduction (IVF/ICSI).

FINDINGS

The proportion of preterm (<37 weeks) births was significantly higher in the case of IVF or ICSI, followed by hormonal treatment, compared to spontaneous pregnancies. There was no significant difference in PTB between SCS and any of the other groups. Concerning the average birth weight we found no significant difference between singletons born after natural conception and SCS. However, a significant difference in average birth weight was found between SCS singletons and singletons born after IVF, ICSI and hormonal treatment, with a significantly higher birth weight in the SCS group. This difference was also observed in the proportion of babies weighing less than 2500 g, with significantly more LBW babies in the IVF and ICSI group compared to the SCS newborns.

INTERPRETATION

Taking into account the small series, PTB and LBW rates in SCS singletons were found to be comparable with singletons born after natural conception. Compared to babies born after ovarian stimulation and IVF/ICSI, SCS singletons had a lower PTB and LBW rates, although the differences were not significant for PTB. Our results confirm previous reports on reassuring perinatal outcomes after using the SCS technology.

Association of chorioamnionitis with infertility treatment and subsequent neonatal outcomes in the US: a population-based cohort study

BACKGROUND

Chorioamnionitis (CAM) is a common risk factor for preterm births, resulting in several adverse outcomes. The association between infertility treatment and CAM is unclear. Therefore, this study examined the association between infertility treatment and CAM and described subsequent neonatal outcomes.

METHODS

This population-based cohort study used data from the National Vital Statistics System Database. We included women who had a singleton live birth from January 1, 2016 to December 31, 2018. Women-infant pairs were stratified by infertility treatment, and the main outcome was a reported diagnosis of CAM in a checkbox format: clinical CAM or maternal temperature of > 38 °C. Multivariate logistic regression was used to examine the association between infertility treatment and CAM and the effect of infertility treatment on neonatal outcomes in women diagnosed with CAM.

RESULTS

The final sample comprised 10,900,495 woman-infant pairs, and 1.4% received infertility treatment. Compared with the natural conception group, women receiving infertility treatment had a significantly higher risk of CAM (adjusted odds ratio [aOR] 1.772 [95% confidence interval {CI}, 1.718-1.827]). Furthermore, newborns exposed to CAM had a higher risk of very low birth weight (VLBW) (aOR, 2.083 [95% CI, 1.664-2.606], P < .001), preterm birth (aOR, 1.497 [95% CI, 1.324-1.693]; P < .001), neonatal intensive care unit admission (aOR, 1.234 [95% CI, 1.156-1.317]; P < .001), and other adverse neonatal outcomes in the infertility treatment group compared with ones conceived naturally.

CONCLUSIONS

This study found that women who received infertility treatment had a higher risk of CAM. And CAM deteriorated neonatal outcomes in the infertility treatment group.

Expression of Toll-Like Receptors in the Lung Tissue of Mouse Fetuses Generated by in vitro Embryo Culture and Embryo Transfer

Mouse fetuses generated by in vitro embryo culture and embryo transfer exhibit impaired lung development, altered composition of pulmonary epithelial cells associated with downregulation of several genes involved in lung development and toll-like receptor (TLR) signaling pathway. The aims of the present study were to determine the expression of all TLRs and to examine if the expression of TLRs, along with genes involved in TLR signaling pathway, is altered in the lung tissue of mouse fetuses generated through embryo culture and embryo transfer. Two experimental (EGs) and one control (CG) group were included in the study. Embryos cultured at 5% CO2-95% air for 95 h or less than 24 h were transferred to pseudo-pregnant females to obtain fetuses comprising EGin vitro (n = 18) and EGin vivo (n = 18), respectively. Fetuses obtained from naturally ovulating females on day 18 of pregnancy served as the CG (n = 18). Western blot and immunohistochemistry were used to determine the expression of TLR proteins. The expression of transcripts encoding TLRs, and the genes involved in TLR signaling pathway (Lbp, Pik3r1, Pik3cb, Nfkbia, and Fos), was determined using qRT-PCR. While all TLRs were expressed by cells lining the bronchial/bronchiolar epithelium of lung tissues in all groups, some of the TLRs were expressed in a specific pattern. When compared to CG, the expression of transcripts encoding TLR-2, -3, -4, -5, -7, -8, -9, -12, -13, Lbp, Pik3r1, Pik3cb, Nfkbia, and Fos was significantly downregulated in both EGs. It appears that stress imposed on embryos at preimplantation stages of development is associated with downregulation of TLRs, along with some of the genes involved in TLR signaling pathway, in the lung tissue during the perinatal period. It remains to be determined if downregulation of TLRs, along with the genes involved in TLR signaling pathway, has any functional consequences in the adult lung tissue.

Promising Perinatal Outcome after Using a Simplified Low-Cost IVF Culture System Specifically Designed for Resource-Poor Countries

Background: Assisted reproductive techniques services are often not accessible to the majority of infertile couples in Low and Middle Income Countries (LMIC) due to high costs. Lowering IVF laboratory costs is a crucial step to make IVF affordable for a larger part of the world population. We developed a simplified culture system (SCS) which has proven to be effective, and the next step is to prove its safety.Methods: Preterm birth (PTB) and low birthweight (LBW) of 176 singletons born after using the SCS, 105 after fresh embryo transfer (fresh ET), and 71 after frozen embryo transfer (frozen ET) were compared with all IVF/ICSI singletons born in Belgium between 2013 and 2018. When comparing our 105 SCS babies born after fresh ET with all Belgian babies born after conventional IVF only, we also adjusted for 7 risk factors known to influence perinatal outcome, namelythe mother’s age, day of transfer, pituitary inhibition protocol, rank of cycles, number of oocytes retrieved, number of embryos transferred, and gender of the baby.Findings: Before adjustment, we found a significantly higher PTB (10.2% vs. 3.8%, OR 2.852, 95% CI [1.042–7.803], p-value 0.0413) and LBW (9.8% vs. 2.9%, OR 3.692, 95% CI [1.163–11.721], p-value 0.0267) in the conventional IVF group versus SCS after fresh ET. After adjusting for seven risk parameters, these differences remained significant (PTB: OR 2.627, 95% CI [1.013–6.816], p-value 0.0471) and LBW: OR 3.267, 95% CI [1.118–9.549], p-value 0.0305). PTB and LBW between both groups was not significantly different for singletons born after frozen ET. Interpretation: Taking into account the small series, PTB and LBW rates in SCS singletons in FRET cycles are very reassuring and significantly lower compared to babies born after conventional IVF in Belgium. Being aware of its effectiveness, our results offer a good perspective for SCS to become an important tool to implement low-cost IVF in LMIC.

Growth of twins conceived using assisted reproductive treatments up to 5 years old: a national growth cohort

STUDY QUESTION

Do twins conceived through assisted reproductive treatments (ART) grow differently from naturally conceived (NC) twins in early life?

SUMMARY ANSWER

Assessments at 6-8 weeks old and at school entry show that ART twins conceived from frozen embryo transfer (FET) grow faster than both NC twins and ART twins conceived from fresh embryo transfer (ET).

WHAT IS KNOWN ALREADY

Singletons born from fresh ET grow more slowly in utero and in the first few weeks of life but then show postnatal catch-up growth by school age, compared to NC and FET babies. Evidence on early child growth of ART twins relative to NC twins is inconsistent; most studies are small and do not distinguish FET from fresh ET cycles.

STUDY DESIGN, SIZE, DURATION

This cohort study included 13 528 live-born twin babies conceived by ART (fresh ET: 2792, FET: 556) and NC (10 180) between 1991 and 2009 in Scotland. The data were obtained by linking Human Fertilisation and Embryology Authority ART register data to the Scottish Morbidity Record (SMR02) and Scottish child health programme datasets. Outcome data were collected at birth, 6-8 weeks (first assessment), and school entry (4-7 years old) assessments. The primary outcome was growth, measured by weight at the three assessment points. Secondary outcomes were length (at birth and 6-8 weeks) or height (at school entry), BMI, occipital circumference, gestational age at birth, newborn intensive care unit admission, and growth rates (between birth and 6-8 weeks and between 6-8 weeks and school entry).

PARTICIPANTS/MATERIALS, SETTING, METHODS

All twins in the linked dataset (born between 1991 and 2009) with growth data were included in the analysis. To determine outcome differences between fresh ET, FET, and NC twins, linear mixed models (or analogous logistic regression models) were used to explore the outcomes of interest. All models were adjusted for available confounders: gestational age/child age, gender, maternal age and smoking, Scottish Index of Multiple Deprivation, year of treatment, parity, ICSI, and ET stage.

MAIN RESULTS AND THE ROLE OF CHANCE

In the primary birth weight models, the average birth weight of fresh ET twins was lower [-35 g; 95% CI: (-53, -16)g] than NC controls, while FET twins were heavier [71 g; 95% CI (33, 110) g] than NC controls and heavier [106 g; 95% CI (65, 146) g] than fresh ET twins. However, the difference between FET and NC twins was not significant when considering only full-term twins (≥37 weeks gestation) [26 g; 95% CI (-30, 82) g], while it was significantly higher in preterm twins [126 g; 95% CI (73, 179) g]. Growth rates did not differ significantly for the three groups from birth to 6-8 weeks. However, FET twins grew significantly faster from 6 to 8 weeks than NC (by 2.2 g/week) and fresh ET twins (by 2.1 g/week). By school entry, FET twins were 614 g [95% CI (158, 1070) g] and 581 g [95% CI (100, 1063) g] heavier than NC and fresh ET twins, respectively. Length/height and occipital frontal circumference did not differ significantly at any time point.

LIMITATIONS, REASONS FOR CAUTION

Although the differences between ART and NC reflect the true ART effects, these effects are likely to be mediated partly through the different prevalence of mono/dizygotic twins in the two groups. We could not explore the mediating effect of zygosity due to the unavailability of data. The confounding variables included in the study were limited to those available in the datasets.

WIDER IMPLICATIONS OF THE FINDINGS

Live-born twins from FET cycles are heavier at birth, grow faster than their fresh ET and NC counterparts, and are still heavier at school entry. This differs from that observed in singletons from the same cohort, where babies in the three conception groups had similar weights by school entry age. The results are reassuring on known differences in FET versus fresh ET and NC twin outcomes. However, FET twins grow faster and are consistently larger, and more ART twins depict catch-up growth. These may lead to an increased risk profile for non-communicable diseases in later life. As such, these twin outcomes require careful evaluation using more recent and comprehensive cohorts.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by the EU H2020 Marie Sklodowska-Curie Innovative Training Networks (ITN) grant Dohartnet (H2020-MSCA-ITN-2018-812660). The authors have no competing interests to declare.

TRIAL REGISTRATION NUMBER

N/A.

Risk of stillbirth and neonatal death in singletons born after fresh and frozen embryo transfer: cohort study from the Committee of Nordic Assisted Reproduction Technology and Safety

OBJECTIVES

To investigate whether risks of stillbirth and neonatal death differ after fresh embryo transfers (fresh-ETs) and frozen embryo transfers (frozen-ETs) compared with singletons conceived without medical assistance.

DESIGN

A population-based cohort study.

SETTING

Not applicable.

PATIENT(S)

Data linkage between the nationwide Medical Birth Registries in Denmark (1994-2014), Norway and Sweden (1988-2015), and national quality registries and databases on assisted reproductive technology identified a total of 4,590,853 singletons, including 78,642 conceived by fresh-ET and 18,084 by frozen-ET.

INTERVENTION(S)

None MAIN OUTCOME MEASURE(S): Stillbirth (fetal death before and during delivery) and neonatal death (live born with death 0-27 days postpartum).

RESULT(S)

Overall, 17,123 (0.37%) singletons were stillborn and 7,685 (0.17%) died neonatally. Compared with singletons conceived without medical assistance, the odds of stillbirth were similar after fresh-ET and frozen-ET, whereas the odds of neonatal death were high after fresh-ET (odds ratio [OR], 1.69; 95% confidence interval [CI], 1.46-1.95) and frozen-ET (OR, 1.51; 95% CI, 1.08-2.10). Preterm birth (<37 gestational weeks) was more common after fresh-ET (8.0%) and frozen-ET (6.6%) compared with singletons conceived without medical assistance (5.0%), and strongly associated with neonatal mortality across all conception methods. Within gestational age categories, risk of stillbirth and neonatal death was similar for all conception methods, except that singletons from fresh-ET had a higher risk of stillbirth during gestational week 22-27 (OR, 1.85; 95% CI, 1.51-2.26).

CONCLUSION(S)

Overall, the risk of stillbirth was similar after fresh-ET and frozen-ET compared with singletons conceived without medical assistance, whereas neonatal mortality was high, possibly mediated by the high risk of preterm birth when compared with singletons conceived without medical assistance. Our results gave no clear support for choosing one treatment over the other.

Reproductive outcomes in women and men conceived by assisted reproductive technologies in Norway: prospective registry based study

Objectives

To determine whether the perinatal outcomes of women or men who were conceived by assisted reproductive technologies are different compared with their peers who were naturally conceived.

Design

Prospective registry based study.

Setting

Medical Birth Registry of Norway.

Participants

People born in Norway between 1984 and 2002 with a registered pregnancy by the end of 2021.

Exposure

People who were conceived by assisted reproductive technologies and have had a registered pregnancy.

Main outcome measures

Comparing pregnancies and births of people who were conceived by assisted reproductive technologies and people who were naturally conceived, we assessed mean birth weight, gestational age, and placental weight by linear regression, additionally, the odds of congenital malformations, a low 5 min Apgar score (<7), transfer to a neonatal intensive care unit, delivery by caesarean section, use of assisted reproductive technologies, hypertensive disorders of pregnancy and pre-eclampsia, preterm birth, and offspring sex, by logistic regression. The occurrence of any registered pregnancy from people aged 14 years until age at the end of follow-up was assessed using Cox proportional regression for both groups.

Results

Among 1 092 151 people born in Norway from 1984 to 2002, 180 652 were registered at least once as mothers, and 137 530 as fathers. Of these, 399 men and 553 women were conceived by assisted reproductive technologies. People who were conceived by assisted reproductive technologies had little evidence of increased risk of adverse outcomes in their own pregnancies, increased use of assisted reproductive technologies, or any difference in mean birth weight, placental weight, or gestational age. The only exception was for an increased risk of the neonate having a low Apgar score at 5 min (adjusted odds ratio 1.86 (95% confidence interval 1.20 to 2.89)) among women who were conceived by assisted reproductive technologies. Odds were slightly decreased of having a boy among mothers conceived by assisted reproductive technologies (odds ratio 0.79 (95% confidence interval 0.67 to 0.93)). People conceived by assisted reproductive technologies were slightly less likely to have a registered pregnancy within the follow-up period (women, adjusted hazard ratio 0.88 (95% CI 0.81 to 0.96); men, 0.91 (0.83 to 1.01)).

Conclusions

People conceived by assisted reproductive technologies were not at increased risk of obstetric or perinatal complications when becoming parents. The proportion of people conceived by assisted reproductive technologies with a registered pregnancy was lower than among people who were naturally conceived, but a longer follow-up is required to fully assess their fertility and reproductive history.

The longer-term effects of IVF on offspring from childhood to adolescence

It is well established that there are increased pregnancy-related complications for a woman who conceives through assisted reproductive treatment (ART). Furthermore, it is known that the risk to the child born is greater, believed to be related to prematurity and growth restriction. Studies have also reported epigenetic changes in the DNA of offspring conceived through ART. In addition, it is believed that they have a greater risk of congenital malformations, although some of these risks may relate to underlying infertility, rather than the ART treatment per se. As a result, it may be expected that there is a greater risk to the longer-term health of the child who is born from ART; however, evidence about the long-term health of children conceived through ART is reassuring. Even though, it is recognised that many of the studies in this field come with limitations. Low numbers of participants is one of the major limitations, which makes subgroup analyses for diverse types of ART, or diverse types of infertility, not feasible. Furthermore, studies are often limited by short follow-up periods because of the difficulty and costs involved in longitudinal study designs. In addition, the rapid changes over time in ART limit the generalisability and significance of long-term findings. Well-designed studies investigating the long-term health outcomes of ART-conceived offspring and the potential influences of various aspects of the ART procedure, as well as studies of the potential underlying epigenetic mechanisms, are imperative. Furthermore, conclusions from childhood hospitalisation data from the United Kingdom, the long-term follow-up and quality of life study from researchers in Melbourne, and the data published from the Western Australian Growing Up Healthy Study will go a long way to help reassure current and prospective parents who may require ART to conceive.

The Well-Being of Adolescents Conceived Through Medically Assisted Reproduction: A Population-Level and Within-Family Analysis

Medically assisted reproduction (MAR) plays an increasingly important role in the realization of fertility intentions in advanced societies, yet the evidence regarding MAR-conceived children's longer-term well-being remains inconclusive. Using register data on all Finnish children born in 1995-2000, we compared a range of social and mental health outcomes among MAR- and naturally conceived adolescents in population-averaged estimates, and within families who have conceived both through MAR and naturally. In baseline models, MAR-conceived adolescents had better school performance and the likelihood of school dropout, not being in education or employment, and early home-leaving were lower than among naturally conceived adolescents. No major differences were found in mental health and high-risk health behaviours. Adjustment for family sociodemographic characteristics attenuated MAR adolescents' advantage in social outcomes, while increasing the risk of mental disorders. The higher probability of mental disorders persisted when comparing MAR adolescents to their naturally conceived siblings. On average, MAR adolescents had similar or better outcomes than naturally conceived adolescents, largely due to their more advantaged family backgrounds, which underscores the importance of integrating a sociodemographic perspective in studies of MAR and its consequences.

Murine blastocysts generated by in vitro fertilization show increased Warburg metabolism and altered lactate production

In vitro fertilization (IVF) has resulted in the birth of over 8 million children. Although most IVF-conceived children are healthy, several studies suggest an increased risk of altered growth rate, cardiovascular dysfunction, and glucose intolerance in this population compared to naturally conceived children. However, a clear understanding of how embryonic metabolism is affected by culture condition and how embryos reprogram their metabolism is unknown. Here, we studied oxidative stress and metabolic alteration in blastocysts conceived by natural mating or by IVF and cultured in physiologic (5%) or atmospheric (20%) oxygen. We found that IVF-generated blastocysts manifest increased reactive oxygen species, oxidative damage to DNA/lipid/proteins, and reduction in glutathione. Metabolic analysis revealed IVF-generated blastocysts display decreased mitochondria respiration and increased glycolytic activity suggestive of enhanced Warburg metabolism. These findings were corroborated by altered intracellular and extracellular pH and increased intracellular lactate levels in IVF-generated embryos. Comprehensive proteomic analysis and targeted immunofluorescence showed reduction of lactate dehydrogenase-B and monocarboxylate transporter 1, enzymes involved in lactate metabolism. Importantly, these enzymes remained downregulated in the tissues of adult IVF-conceived mice, suggesting that metabolic alterations in IVF-generated embryos may result in alteration in lactate metabolism. These findings suggest that alterations in lactate metabolism are a likely mechanism involved in genomic reprogramming and could be involved in the developmental origin of health and disease.

Altered Expression of Pulmonary Epithelial Cell Markers in Fetal and Adult Mice Generated by in vitro Embryo Culture and Embryo Transfer

Lung development is impaired in mice generated through transfer of in vitro-derived blastocysts. The main objective of the current study was to determine if the composition of epithelial cells in the fetal and adult lung tissue is altered in mice generated through transfer of in vitro-derived blastocysts. The study comprised two experimental (EGs) and two control (CGs) groups. Fetuses (18.5 d.p.c.) and adult mice (8 weeks old) of the EGs (EGfetus, n = 18; EGadult, n = 15) were produced by the transfer of day 5 F2 blastocysts to pseudo-pregnant females. F2 fetuses and adult mice derived from naturally ovulating females served as the CGs (CGfetus, n = 18; CGadult, n = 15). The expression of Tuba-1a (a marker of ciliated cells), Foxj-1 (a marker of motile ciliated cells), Uch-L1 (a marker of neuroendocrine cells), Cldn-10 (a marker of club cells), Aqp-5 (a marker of type I alveolar cells), and Sp-C (a marker of type II alveolar cells) was determined using Western blot, immunohistochemistry/immunofluorescence, and quantitative RT-PCR analyses. Weight of fetuses as well as adult mice is decreased in mice comprising the EGs. Impaired lung development observed in EGfetus was associated with altered expression of Tuba-1a, Foxj-1, Cldn-10, Uch-L1, Sp-C, and Aqp-5. Morphology of the adult lung tissue was similar between the groups except for a significant increase in the thickness of the epithelia in EGadult. The expression of Cldn-10 and Sp-C was also altered in EGadult. It remains to be determined whether altered expression of these genes has any long-term impact on epithelial cell functions in the adult lung tissue.

Cancer in children born after frozen-thawed embryo transfer: A cohort study

BACKGROUND

The aim was to investigate whether children born after assisted reproduction technology (ART), particularly after frozen-thawed embryo transfer (FET), are at higher risk of childhood cancer than children born after fresh embryo transfer and spontaneous conception.

METHODS AND FINDINGS

We performed a registry-based cohort study using data from the 4 Nordic countries: Denmark, Finland, Norway, and Sweden. The study included 7,944,248 children, out of whom 171,774 children were born after use of ART (2.2%) and 7,772,474 children were born after spontaneous conception, representing all children born between the years 1994 to 2014 in Denmark, 1990 to 2014 in Finland, 1984 to 2015 in Norway, and 1985 to 2015 in Sweden. Rates for any cancer and specific cancer groups in children born after each conception method were determined by cross-linking national ART registry data with national cancer and health data registries and population registries. We used Cox proportional hazards models to estimate the risk of any cancer, with age as the time scale. After a mean follow-up of 9.9 and 12.5 years, the incidence rate (IR) of cancer before age 18 years was 19.3/100,000 person-years for children born after ART (329 cases) and 16.7/100,000 person-years for children born after spontaneous conception (16,184 cases). Adjusted hazard ratio (aHR) was 1.08, 95% confidence interval (CI) 0.96 to 1.21, p = 0.18. Adjustment was performed for sex, plurality, year of birth, country of birth, maternal age at birth, and parity. Children born after FET had a higher risk of cancer (48 cases; IR 30.1/100,000 person-years) compared to both fresh embryo transfer (IR 18.8/100,000 person-years), aHR 1.59, 95% CI 1.15 to 2.20, p = 0.005, and spontaneous conception, aHR 1.65, 95% CI 1.24 to 2.19, p = 0.001. Adjustment either for macrosomia, birth weight, or major birth defects attenuated the association marginally. Higher risks of epithelial tumors and melanoma after any assisted reproductive method and of leukemia after FET were observed. The main limitation of this study is the small number of children with cancer in the FET group.

CONCLUSIONS

Children born after FET had a higher risk of childhood cancer than children born after fresh embryo transfer and spontaneous conception. The results should be interpreted cautiously based on the small number of children with cancer, but the findings raise concerns considering the increasing use of FET, in particular freeze-all strategies without clear medical indications.

TRIAL REGISTRATION

Trial registration number: ISRCTN 11780826.

Puberty disorders among ART-conceived singletons: a Nordic register study from the CoNARTaS group

STUDY QUESTION

Do ART-conceived children have an increased risk for puberty disorders?

SUMMARY ANSWER

Both ART-conceived boys and girls had a higher risk of puberty disorders; early puberty was more common among girls and late puberty among boys.

WHAT IS KNOWN ALREADY

Some physiological differences in growth and metabolism have been reported for ART-conceived children compared to non-ART-conceived children. Knowledge on pubertal development and disorders in ART-conceived children is limited.

STUDY DESIGN, SIZE, DURATION

A register-based cohort study was carried out including data from 1985 to 2015. The Committee of Nordic Assisted Reproductive Technology and Safety (CoNARTaS) study population consists of all live and stillborn children, as well as their mothers, registered in the Medical Birth Registers during the study period in Denmark, Sweden, Finland and Norway.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 122 321 ART-conceived singletons and 6 576 410 non-ART singletons born in Denmark (1994–2014), Finland (1990–2014), Norway (2002–2015) and Sweden (1985–2015) were included. Puberty disorders were defined using International Classification of Diseases and Related Health Problems (ICD)-9/ICD-10 codes and classified in the following groups: late puberty (6268/E30.0), early puberty (2591 and 2958/E30.1 and E30.8) and unspecified disorders (V212 and V579/E30.9 and Z00.3 as well as Z51.80 for Finland). The results in Cox regression were adjusted for maternal age, parity, smoking, gestational diabetes, chronic hypertension, hypertensive disorders during pregnancy and country, and further for either gestational age, birthweight, small for gestational age or large for gestational age.

MAIN RESULTS AND THE ROLE OF CHANCE

There were 37 869 children with diagnoses related to puberty disorders, and 603 of them were born after ART. ART-conceived children had higher risks for early (adjusted hazard ratio (aHR) 1.45, 95% CI: 1.29–1.64) and late puberty (aHR 1.47, 95% CI: 1.21–1.77). Girls had more diagnoses related to early puberty (aHR 1.46, 95% CI: 1.29–1.66) and boys with late puberty (aHR 1.55, 95% CI: 1.24–1.95).

LIMITATIONS, REASONS FOR CAUTION

Using reported puberty disorders with ICD codes in health care registers might vary, which may affect the numbers of cases found in the registers. Register data may give an underestimation both among ART and non-ART-conceived children, especially among non-ART children, who may not be as carefully followed as ART-conceived children. Adjustment for causes and duration of infertility, mothers’ own puberty characteristics and BMI, as well as children’s BMI, was not possible because data were not available or data were missing for the early years. It was also not possible to compare ART to non-ART siblings or to study the pubertal disorders by cause of subfertility owing to a small number of discordant sibling pairs and a large proportion of missing data on cause of subfertility.

WIDER IMPLICATIONS OF THE FINDINGS

This large, register-based study suggests that ART-conceived children have a higher risk for puberty disorders. However, the mechanisms of infertility and pubertal onset are complex, and ART is a rapidly advancing field with various treatment options. Studying the pubertal disorders of ART-conceived offspring is a continuing challenge.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by the Nordic Trial Alliance: a pilot project jointly funded by the Nordic Council of Ministers and NordForsk (71450), the Central Norway Regional Health Authorities (46045000), the Nordic Federation of Obstetrics and Gynaecology (NF13041, NF15058, NF16026 and NF17043), the Interreg Öresund-Kattegat-Skagerrak European Regional Development Fund (ReproUnion project), the Research Council of Norway’s Centre of Excellence funding scheme (262700), the Swedish state under the agreement between the Swedish government and the county councils, the ALF-agreement (ALFGBG-70940) and FLUX Consortium ‘Family Formation in Flux—Causes, Consequences and Possible Futures’, funded by the Strategic Research Council, Academy of Finland (DEMOGRAPHY 345130). The funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript. The authors have no conflicts of interest to disclose.

TRIAL REGISTRATION NUMBER

N/A.

The low fetal fraction at the first trimester is associated with adverse pregnancy outcomes in IVF singleton pregnancies with single embryo transfer from frozen cycles

PURPOSE

To study the associations between fetal fraction at the first trimester and subsequent adverse pregnancy outcomes (APOs) in IVF singleton pregnancies with single embryo transfer from frozen cycles.

METHODS

This is a single-center retrospective cohort study on IVF singleton pregnancies with single embryo transfer from frozen cycles. A total of 8457 women were collected between March 2015 and September 2018 from the Center for Reproductive Medicine, Shandong University, China. Participants underwent cell-free DNA (cfDNA) sequencing at 11-13 weeks' gestation. Multivariable logistic regressions were performed with the risk of APOs based on various predictor variables.

RESULTS

A total of 8457 women were included in the analysis of which 1563 (18.48%) women developed one or more APOs. The hypertensive disorders of pregnancy (HDP) (N = 515), gestational diabetes mellitus (GDM) (N = 684), preterm birth (PTB) (N = 567), and low birth weight (LBW) (N = 306) groups had lower fetal fraction compared with the no pregnancy complication (NPC) group (all p values < 0.05). Based on the multivariable logistic regression results, the optimal cutoff values of fetal fraction were 9.30%, 12.54%, 9.10%, 12.65%, and 13.83% for at least one APO, HDP, GDM, PTB, and LBW, respectively. After adjustment for potential maternal confounders, women in the low fetal fraction (LFF) group had a higher risk for the APOs compared with high fetal fraction (HFF) group.

CONCLUSIONS

The fetal fraction in HDP, GDM, PTB, and LBW groups were lower than NPC group in IVF singleton pregnancies with single embryo transfer from frozen cycles in China.

Perinatal outcome of babies born after using a simplified IVF culture system versus ICSI with sibling oocytes: a prospective cohort study

RESEARCH QUESTION

Is there a difference in perinatal outcome in the same patient cohort for babies conceived following randomization of sibling oocytes allocated to a simplified IVF culture system (SCS) or intracytoplasmic sperm injection (ICSI) followed by conventional culturing?

DESIGN

The study compared the perinatal outcomes of 367 babies born from 1 January 2013 until 31 December 2020 after using split SCS and ICSI insemination of sibling oocytes in a selected group of normo-responsive women, excluding cases of severe male infertility. Primary outcome measures were preterm birth (PTB; <37 weeks' gestation), low birthweight (LBW; <2.5 kg) and small for gestational age (SGA) as a primary outcome parameter while secondary outcome measures included mean birthweight, mean gestational age, extreme prematurity (<32 weeks), very low birthweight (<1.5 kg), perinatal mortality, multiple pregnancy and Caesarean section rate.

RESULTS

A total of 105 and 103 singleton babies were born after fresh embryo transfer (FRET) and 71 and 50 singletons after frozen embryo transfer (FET) in the SCS and ICSI groups, respectively. For babies born after FRET, the LBW rate was 2.9% (3/105) for SCS and 7.8% (8/103) for ICSI (P = 0.10). LBW occurred in 4.2% (3/71) and 0% (0/50) of babies born after the transfer of cryopreserved-thawed SCS and ICSI embryos, respectively (P = 0.14). The rate of PTB was 3.8% and 6.8% for SCS and ICSI in FRET cycles (P = 0.33), and 8.5% and 6.0% for SCS and ICSI in FET cycles (P = 0.62). One congenital malformation was found in the SCS FET group.

CONCLUSION

There was no difference in perinatal outcome for singleton and twin babies born after SCS and ICSI.

Maternal and obstetric outcomes are influenced by developmental stage and cryopreservation of transferred embryos after clomiphene citrate-based minimal stimulation IVF

STUDY QUESTION

Is the embryo transfer (ET) method associated with maternal and perinatal outcomes after minimal stimulation IVF using clomiphene citrate (CC)?

SUMMARY ANSWER

The incidence of pregnancy complications and adverse perinatal outcomes was influenced by the developmental stage (cleavage versus blastocyst stages) and cryopreservation (fresh versus vitrified) of the transferred embryos.

WHAT IS KNOWN ALREADY

Pregnancies resulting from IVF are associated with higher risks of adverse perinatal outcomes compared to natural conceptions; therefore, the next focus in reproductive medicine should be to assess whether these increased risks are attributable to IVF. Pregnancy complications and perinatal outcomes should be considered in addition to pregnancy outcomes when selecting the ET method, however, studies that describe the influence of transfer methods on perinatal and maternal outcomes are limited.

STUDY DESIGN, SIZE, DURATION

This study retrospectively analysed a large single-centre cohort. The clinical records of 36 827 women who underwent oocyte retrieval (during a CC-based minimal stimulation cycle) followed by their first ET at the fertility treatment centre between January 2008 and December 2017 were retrospectively analysed. The patients underwent a single fresh cleavage-stage ET (SFCT), single vitrified-warmed cleavage-stage ET (SVCT) or single vitrified-warmed blastocyst transfer (SVBT). This study only included one cycle per patient.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Oocyte retrieval was performed following CC-based minimal ovarian stimulation. The embryos were transferred 2–3 days after retrieval or vitrified at the cleavage or blastocyst stage. The vitrified embryos were then warmed and transferred within the natural cycles. Pregnancy complications and perinatal outcomes were stratified according to the transfer methods used. Multivariate logistic regression analysis was performed to evaluate the effect of ET methods on the prevalence of pregnancy complications and congenital anomalies.

MAIN RESULTS AND THE ROLE OF CHANCE

The rates of clinical pregnancy and delivery were significantly different among the groups. We analysed pregnancy complications in 7502 singleton births (SFCT, 3395 cycles; SVCT, 586 cycles; and SVBT, 3521 cycles). Multivariate logistic regression analysis revealed that the adjusted odds ratio (AOR) for hypertensive disorders in pregnancy was significantly lower in the SVBT group than in the SFCT group [AOR, 0.72; 95% CI, 0.56–0.92]. The AOR for low-lying placenta was lower in the SVBT group than in the SFCT group (AOR, 0.34; 95% CI, 0.19–0.60). The AOR for placenta previa was lower in the SVCT and SVBT groups than in the SFCT group (AOR, 0.21; 95% CI, 0.07–0.58 versus AOR, 0.53; 95% CI, 0.38–0.75, respectively). A total of 7460 follow-up data on neonatal outcomes was analysed. The AOR for preterm delivery was lower in the SVBT group than in the SFCT group (AOR, 0.78; 95% CI, 0.64–0.94). The AOR for low birthweight was significantly lower after SVCT and SVBT than after SFCT (AOR, 0.68; 95% CI, 0.46–0.98 versus AOR, 0.57; 95% CI, 0.48–0.66, respectively). The AOR for small for gestational age was lower in the SVCT and SVBT groups than in the SFCT group (AOR, 0.68; 95% CI, 0.46–0.98 versus AOR, 0.44; 95% CI, 0.36–0.55, respectively). The AOR for large for gestational age babies was higher in the SVBT group than in the SFCT group (AOR, 1.88; 95% CI, 1.62–2.18). The incidence of each congenital anomaly was similar among the groups.

LIMITATIONS, REASONS FOR CAUTION

The study data were collected through self-reported parental questionnaires on maternal and neonatal outcomes. Our findings were not compared with the incidence of pregnancy complications and congenital anomalies in natural pregnancies. Furthermore, this study was retrospective in nature; therefore, further studies are required to ascertain the generalizability of these findings to other clinics with different protocols and/or different patient demographics.

WIDER IMPLICATIONS OF THE FINDINGS

This study demonstrated reassuring outcomes for SVBT (in terms of a lower incidence of pregnancy complications) compared to SFCT. Our findings provide valuable knowledge that will help improve perinatal and maternal outcomes in CC-based stimulation and inform couples of the possible benefits and risks of each type of ET method.

STUDY FUNDING/COMPETING INTEREST(S)

This research did not receive any specific grants from funding agencies in the public, commercial, or not-for-profit sectors. The authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

DNA methylation in newborns conceived by assisted reproductive technology

Assisted reproductive technology (ART) may affect fetal development through epigenetic mechanisms as the timing of ART procedures coincides with the extensive epigenetic remodeling occurring between fertilization and embryo implantation. However, it is unknown to what extent ART procedures alter the fetal epigenome. Underlying parental characteristics and subfertility may also play a role. Here we identify differences in cord blood DNA methylation, measured using the Illumina EPIC platform, between 962 ART conceived and 983 naturally conceived singleton newborns. We show that ART conceived newborns display widespread differences in DNA methylation, and overall less methylation across the genome. There were 607 genome-wide differentially methylated CpGs. We find differences in 176 known genes, including genes related to growth, neurodevelopment, and other health outcomes that have been associated with ART. Both fresh and frozen embryo transfer show DNA methylation differences. Associations persist after controlling for parents' DNA methylation, and are not explained by parental subfertility.

Bioethics in human embryology: the double-edged sword of embryo research

There has been a significant increase in the use of assisted reproductive therapies (ARTs) over the past several decades, allowing many couples with infertility to conceive. Despite the achievements in this field, a mounting body of evidence concerning the epigenetic risks associated with ART interventions such as ovarian hormonal stimulation, intracytoplasmic sperm injection (ICSI), and in vitro culture (IVC) of oocytes and embryos has also emerged. Induced development of multiple follicles, the IVC media itself, and extended culture may alter the epigenome of both gametes and embryos, resulting in yet to be fully understood developmental, postnatal, and adult life health consequences. Investigators have attempted to decipher the molecular mechanisms mediating ART-induced epigenetic changes using either human samples or animal models with some success. As research in this field continues to expand, the ethical responsibilities of embryologists and researchers have become critically important. Here, we briefly discuss the ethical aspects of ART research, concentrating on the constraints arising from the perceived 'unnaturalness' of many of these procedures. Secondly, we focus on the bioethics and morality of human embryo research in general and how ethically acceptable model systems may be used to mimic early human embryogenesis. Lastly, we review the 14-day culture limit of human embryos and the notion that this rule could be considered of taken into account using new technologies and cues from animal models. The 'black box' of early post-implantation embryogenesis might be revealed using embryo models. As long as this distinct moral line has been drawn and closely followed, we should not fear scientific growth in embryo research. Although in vitro fertilization (IVF) is ethically acceptable, research with human embryos to improve its success raises serious ethical concerns that are in need of constant revisiting.Glossary index: Moral status: the ascription of obligations and rights to embryos on the basis of sentience; Sentience: the capacity of the developing embryo to experience feelings and sensations, such as the awareness of pain; Ectogenesis: the growth of the embryo in an artificial environment outside the mother's body.

Perinatal outcomes of singletons born after blastocyst or cleavage-stage embryo transfer in FET cycles

PURPOSE

To compare perinatal outcomes of singletons after blastocyst versus cleavage-stage embryo transfer in frozen-thawed embryo transfer (FET) cycles.

METHODS

This was a retrospective cohort study of 4835 women who conceived after frozen-thawed embryo transfer and delivered a singleton baby from January 2015 to March 2020. The perinatal outcomes of the singletons born after blastocyst transfer (N = 3364) were compared to the singletons born after cleavage-stage transfer (N = 1471), including gestational week, birth weight, newborn gender and Apgar score.

RESULTS

Univariate and multivariate analysis found that infants born after blastocyst transfer had a higher risk of preterm birth (PTB) [adjusted odds ratio (aOR) 1.480; 95% confidence interval (CI) 1.213-1.807], large for gestational age (LGA) (aOR 1.329, 95%CI 1.149-1.536) and very large for gestational age (VLGA) (aOR 1.317, 95%CI 1.092-1.590) compared to infants born after cleavage-stage embryo transfer. When categorized by gestational weeks, the proportion of LGA was significantly higher for boys born after BT between GW 37 to 41 (aOR 1.301, 95%CI 1.051-1.609) and for girls born after BT between GW 32 to 41 (aOR 2.690, 95%CI 1.154-6.271, aOR 1.377, 95%CI 1.094-1.733), compared to boys and girls born after CT.

CONCLUSION

Our data suggested that the risk of PTB and LGA increased after blastocyst transfer versus cleavage-stage embryo transfer in FET cycles, and the risk of LGA is more apparent in the last trimester of pregnancy. Further studies are needed to confirm our findings and explored the association between the extended embryo culture and long-term outcomes of offspring.

Effects of early maternal cancer and fertility treatment on the risk of adverse birth outcomes

BACKGROUND

Early maternal cancer and fertility treatment each increase the risk for adverse birth outcomes, but the joint effect of these outcomes has not yet been reported. Thus, the aim was to assess the individual and joint effect of maternal cancer and fertility treatment on the risk for adverse birth outcomes.

METHODS

This population-based cohort study included 5487 live-born singletons identified in the Danish Medical Birth Register (1994-2016) of mothers with previous cancer (<40 years) recorded in the Danish Cancer Registry (1955-2014). We randomly selected 80,262 live-born singletons of mothers with no cancer <40 years matched to mothers with cancer by birth year and month. We calculated odds ratios (ORs) for preterm birth, low birth weight (LBW) (<2500 g) and small for gestational age (SGA), mean differences in birth weight in grams, and additional cases of preterm birth (gestational age<259 days) per 100,000 person-years. Multiplicative and additive interaction of maternal cancer and fertility treatment was compared with outcomes of children conceived naturally to mothers with no maternal cancer (reference group).

FINDINGS

Among 84,332 live-born singletons, increased ORs for preterm birth were observed among children born to mothers with previous cancer (1·48, 95% confidence interval [CI] 1·33-1.65) or after fertility treatment (1·43, 95% 1·28-1-61), with 22 additional cases of preterm birth among both group of children (95% CI 15-29; 95% CI 14-30). In the joint analyses, the OR for SGA for children born after fertility treatment to mothers with previous cancer was similar to that of the reference group (OR 1·02, 95% CI 0·72-1·44, P for interaction=0·52). Children with both exposures had increased ORs for LBW (1·86, 95% CI 1·17-2·96, P for interaction=0·06) and preterm birth (2·31, 955 CI 1·66-3·20, P for interaction = 0·56), with 61 additional cases of preterm birth (95% CI 27-95, P for interaction=0.26) over that of children in the reference group. The mean birth weight was also lower in children born to mothers with both exposures (-140 g, 95% CI -215; -65) (P for interaction=0.06) but decreased to -22 g (95% CI -76; 31) after adjustment for GA.

INTERPRETATION

Although we did not find any statistically significant additive interaction between maternal cancer and fertility treatment, children born after fertility treatment of mothers with previous cancer were at increased risk for adverse birth outcomes. Thus, pregnant women with both exposures need close follow-up during pregnancy.

FUNDING

The Danish Cancer Society and the Danish Childhood Cancer Foundation.

Assisted Reproductive Technology Surveillance - United States, 2018

Problem/Condition

Since the first U.S. infant conceived with assisted reproductive technology (ART) was born in 1981, both the use of ART and the number of fertility clinics providing ART services have increased steadily in the United States. ART includes fertility treatments in which eggs or embryos are handled in the laboratory (i.e., in vitro fertilization [IVF] and related procedures). Although the majority of infants conceived through ART are singletons, women who undergo ART procedures are more likely than women who conceive naturally to have multiple births because multiple embryos might be transferred. Multiple births can pose substantial risks for both mothers and infants, including obstetric complications, preterm birth (<37 weeks), and low birthweight (<2,500 g). This report provides state-specific information for the United States (including the District of Columbia and Puerto Rico) on ART procedures performed in 2018 and compares birth outcomes that occurred in 2018 (resulting from ART procedures performed in 2017 and 2018) with outcomes for all infants born in the United States in 2018.

Period Covered

2018.

Description of System

In 1995, CDC began collecting data on ART procedures performed in fertility clinics in the United States as mandated by the Fertility Clinic Success Rate and Certification Act of 1992 (Public Law 102–493 [October 24, 1992]). Data are collected through the National ART Surveillance System (NASS), a web-based data collection system developed by CDC. This report includes data from the 50 U.S. states, the District of Columbia, and Puerto Rico.

Results

In 2018, a total of 203,119 ART procedures (range: 196 in Alaska to 26,028 in California) were performed in 456 U.S. fertility clinics and reported to CDC. These procedures resulted in 73,831 live-birth deliveries (range: 76 in Puerto Rico and Wyoming to 9,666 in California) and 81,478 infants born (range: 84 in Wyoming to 10,620 in California). Nationally, among women aged 15–44 years, the rate of ART procedures performed was 3,135 per 1 million women. ART use exceeded 1.5 times the national rate in seven states (Connecticut, Illinois, Maryland, Massachusetts, New Jersey, New York, and Rhode Island) and the District of Columbia. ART use rates exceeded the national rate in an additional seven states (California, Delaware, Hawaii, New Hampshire, Utah, Vermont, and Virginia).

Nationally, among all ART transfer procedures, the average number of embryos transferred was similar across age groups (1.3 among women aged <35 years, 1.3 among women aged 35–37 years, and 1.4 among women aged >37 years). The national single-embryo transfer (SET) rate among all embryo-transfer procedures was 74.1% among women aged <35 years (range: 28.2% in Puerto Rico to 89.5% in Delaware), 72.8% among women aged 35–37 years (range: 30.6% in Puerto Rico to 93.7% in Delaware), and 66.4% among women aged >37 years (range: 27.1% in Puerto Rico to 85.3% in Delaware).

In 2018, ART contributed to 2.0% of all infants born in the United States (range: 0.4% in Puerto Rico to 5.1% in Massachusetts) from procedures performed in 2017 and 2018. Approximately 78.6% of ART-conceived infants were singleton infants. Overall, ART contributed to 12.5% of all multiple births, including 12.5% of all twin births and 13.3% of all triplets and higher-order births. ART-conceived twins accounted for approximately 97.1% (15,532 of 16,001) of all ART-conceived multiple births. The percentage of multiple births was higher among infants conceived with ART (21.4%) than among all infants born in the total birth population (3.3%). Approximately 20.7% (15,532 of 74,926) of ART-conceived infants were twins, and 0.6% (469 of 74,926) were triplets and higher-order multiples.

Nationally, infants conceived with ART contributed to 4.2% of all low birthweight (<2,500 g) infants. Among ART-conceived infants, 18.3% were low birthweight compared with 8.3% among all infants. ART-conceived infants contributed to 5.1% of all preterm (gestational age <37 weeks) infants. The percentage of preterm births was higher among infants conceived with ART (26.1%) than among all infants born in the total birth population (10.0%).

The percentage of low birthweight among singletons was 8.3% among ART-conceived infants and 6.6% among all infants born. The percentage of preterm births among ART-conceived singleton infants was 14.9% compared with 8.3% among all singleton infants. The percentages of small for gestational age infants was 7.3% among ART-conceived infants compared with 9.4% among all infants.

Interpretation

Although singleton infants accounted for the majority of ART-conceived infants, multiple births from ART varied substantially among states and nationally, contributing to >12% of all twins, triplets, and higher-order multiple infants born in the United States. Because multiple births are associated with higher rates of prematurity than singleton births, the contribution of ART to poor birth outcomes continues to be noteworthy. Although SET rates increased among all age groups, variations in SET rates among states and territories remained, which might reflect variations in embryo-transfer practices among fertility clinics and might in part account for variations in multiple birth rates among states and territories.

Public Health Action

Reducing the number of embryos transferred and increasing use of SET, when clinically appropriate, can help reduce multiple births and related adverse health consequences for both mothers and infants. Whereas risks to mothers from multiple-birth pregnancy include higher rates of caesarean delivery, gestational hypertension, and gestational diabetes, infants from multiple births are at increased risk for numerous adverse sequelae such as preterm birth, birth defects, and developmental disabilities. Long-term follow-up of ART infants through integration of existing maternal and infant health surveillance systems and registries with data available from NASS might be useful for monitoring adverse outcomes on a population basis.

Association of Preterm Singleton Birth With Fertility Treatment in the US

IMPORTANCE

Preterm birth is a global health issue. The association between fertility treatment and preterm singleton births has not been clarified.

OBJECTIVE

To examine the association between fertility treatment and preterm birth.

DESIGN, SETTING, AND PARTICIPANTS

This population-based cohort study used birth data that were submitted by 50 states and the District of Columbia to the National Vital Statistics System database. All mothers in the database who had a singleton live birth from January 1, 2016, to December 31, 2019, were included. Those who had preexisting hypertension or diabetes were excluded.

EXPOSURES

Fertility treatment categorized as assisted reproductive technology (ART) or non-ART treatment.

MAIN OUTCOMES AND MEASURES

The main outcome was a diagnosis of preterm birth, which was defined as birth before 37 complete weeks (<259 days) of gestation. Gestational age was calculated by obstetric estimation at delivery and was collected from the database.

RESULTS

The final sample consisted of 14 370 920 mothers (mean [SD] age, 28.79 [5.79] years) with singleton live births. Of these women, 122 944 (0.9%) conceived by ART and 71 176 (0.5%) received non-ART treatment. The prevalence of preterm birth was 7.6% (n = 1 071 994) in natural conception, 10.7% (n = 13 205) in ART, and 9.3% (n = 6629) in non-ART groups. Compared with neonates who were naturally conceived, newborns who were conceived with ART (adjusted risk difference [aRD], 3.10% [95% CI, 2.93%-3.27%]; adjusted odds ratio [aOR], 1.49 [95% CI, 1.46-1.52]; P < .001) and non-ART treatment (aRD, 2.22% [95% CI, 2.00%-2.44%]; aOR, 1.35 [95% CI, 1.31-1.38]; P < .001) had significantly higher risk for preterm birth after full adjustment. These associations were similar in subgroups of participants as defined by baseline characteristics.

CONCLUSIONS AND RELEVANCE

This study found that singleton neonates who were conceived by fertility treatment had higher rates of preterm birth. Further investigations are warranted into the association between ART or non-ART treatment and the risk of preterm birth in singleton neonates.

Maternity After Orthotopic Liver Transplantation: Can the Use of Biological Fertility Indicators Help? Our Own Experience and Literature-based Recommendations

Over the last 5 decades, the fulfillment of maternity wishes in solid organ transplanted women has become a reality. Despite pregnancy contraindication in transplanted women during the early post-transplant period, such a condition can be overcome after 12 months if patients show a good clinical evolution and do not present other general pre-conceptional findings. This article presents the case report of a young female liver transplanted patient that used symptothermal method as a reliable family planning method. After her gestational contraindication was lifted, observation of biological fertility indicators and fertility-guided sexual intercourse helped her fulfill her maternity wish and conceive and carry out a healthy offspring. Based on this case and on the available bibliographic evidence, this paper reviews the potential implications of the use of this kind of approach as a safe and effective alternative to assisted reproduction technology in the management of potential infertility problems in the young female transplanted population, a population which according to literature has higher rates of unsuccessful parenthood and might also be more vulnerable to iatrogenicity of ovarian hyperstimulation process and to multiple pregnancy.