The Consequences of Assisted Reproduction Technologies on the Offspring Health Throughout Life: A Placental Contribution

The use of assisted reproductive technologies (ART) worldwide has led to the conception and birth of over eight million babies since being implemented in 1978. ART use is currently on the rise, given growing infertility and the increase in conception age among men and women in industrialized countries. Though obstetric and perinatal outcomes have improved over the years, pregnancies achieved by ART still bear increased risks for the mother and the unborn child. Moreover, given that the first generation of ART offspring is now only reaching their forties, the long-term effects of ART are currently unknown. This is important, as there is a wealth of data showing that life-long health can be predetermined by poor conditions during intrauterine development, including irregularities in the structure and functioning of the placenta. In the current review, we aim to summarize the latest available findings examining the effects of ART on the cardiometabolic, cognitive/neurodevelopmental, and behavioral outcomes in the perinatal period, childhood and adolescence/adulthood; and to examine placental intrinsic factors that may contribute to the developmental outcomes of ART offspring. Altogether, the latest knowledge about life outcomes beyond adolescence for those conceived by ART appears to suggest a better long-term outcome than previously predicted. There are also changes in placenta structure and functional capacity with ART. However, more work in this area is critically required, since the potential consequences of ART may still emerge as the offspring gets older. In addition, knowledge of the placenta may help to foresee and mitigate any adverse outcomes in the offspring.

Why does mode of conception affect early breastfeeding outcomes? A retrospective cohort study

Introduction

It is uncertain whether Assisted Reproductive Technology (ART) is associated with an increased risk of poor breastfeeding outcomes and what could be possible mechanisms. This study aimed to examine the effect of mode of conception on breastfeeding outcomes during the first two months postpartum and identify the potential mediating pathways for this relationship.

Methods

A retrospective cohort study was conducted in a sample of 3,565 women with live births. Participants were classified by mode of conception as follows: fertile women who conceived naturally (fertile women; n = 2,857), women with infertility who conceived naturally (sub-fertile women; n = 483), and women with infertility who conceived through ART (women with infertility; n = 310). The infant-feeding patterns were assessed with four-time points before two months postpartum. Binary and multinomial logistic regression and causal mediation analyses were performed.

Results

The rates of breastfeeding initiation and discontinuation across modes of conception were similar. However, infertile and sub-fertile women had 37% (95% CI 1.02, 1.83) and 56% (95% CI 1.06, 2.27) increased risks of introducing formula before the first week postpartum, respectively, and 35% (95% CI 1.01, 1.82) and 52% (95% CI 1.04, 2.24) higher risks of exclusive breastfeeding for less than one week, respectively, compared to fertile women. The relationships were mainly mediated through multiple gestation and admission to neonatal/pediatric intensive care units (NICU/PICU; proportions of mediation were over 50%). The effects of mode of conception on breastfeeding outcomes became not significant in cases of singleton birth.

Conclusions

Sub-fertile women and women with infertility intended to breastfeed but experienced higher perinatal risks in the early postpartum period. Multiple gestation and admission to NICU/PICU forced them to introduce formula earlier than preferred, thus leading to a shorter duration of exclusive breastfeeding. Single embryo transfer policy and breastfeeding support in NICU/PICU could help those women achieve positive early breastfeeding outcomes.

Transfer of thawed frozen embryo versus fresh embryo to improve the healthy baby rate in women undergoing IVF: the E-Freeze RCT

BACKGROUND

Freezing all embryos, followed by thawing and transferring them into the uterine cavity at a later stage (freeze-all), instead of fresh-embryo transfer may lead to improved pregnancy rates and fewer complications during in vitro fertilisation and pregnancies resulting from it.

OBJECTIVE

We aimed to evaluate if a policy of freeze-all results in a higher healthy baby rate than the current policy of transferring fresh embryos.

DESIGN

This was a pragmatic, multicentre, two-arm, parallel-group, non-blinded, randomised controlled trial.

SETTING

Eighteen in vitro fertilisation clinics across the UK participated from February 2016 to April 2019.

PARTICIPANTS

Couples undergoing their first, second or third cycle of in vitro fertilisation treatment in which the female partner was aged < 42 years.

INTERVENTIONS

If at least three good-quality embryos were present on day 3 of embryo development, couples were randomly allocated to either freeze-all (intervention) or fresh-embryo transfer (control).

OUTCOMES

The primary outcome was a healthy baby, defined as a live, singleton baby born at term, with an appropriate weight for their gestation. Secondary outcomes included ovarian hyperstimulation, live birth and clinical pregnancy rates, complications of pregnancy and childbirth, health economic outcome, and State-Trait Anxiety Inventory scores.

RESULTS

A total of 1578 couples were consented and 619 couples were randomised. Most non-randomisations were because of the non-availability of at least three good-quality embryos (n = 476). Of the couples randomised, 117 (19%) did not adhere to the allocated intervention. The rate of non-adherence was higher in the freeze-all arm, with the leading reason being patient choice. The intention-to-treat analysis showed a healthy baby rate of 20.3% in the freeze-all arm and 24.4% in the fresh-embryo transfer arm (risk ratio 0.84, 95% confidence interval 0.62 to 1.15). Similar results were obtained using complier-average causal effect analysis (risk ratio 0.77, 95% confidence interval 0.44 to 1.10), per-protocol analysis (risk ratio 0.87, 95% confidence interval 0.59 to 1.26) and as-treated analysis (risk ratio 0.91, 95% confidence interval 0.64 to 1.29). The risk of ovarian hyperstimulation was 3.6% in the freeze-all arm and 8.1% in the fresh-embryo transfer arm (risk ratio 0.44, 99% confidence interval 0.15 to 1.30). There were no statistically significant differences between the freeze-all and the fresh-embryo transfer arms in the live birth rates (28.3% vs. 34.3%; risk ratio 0.83, 99% confidence interval 0.65 to 1.06) and clinical pregnancy rates (33.9% vs. 40.1%; risk ratio 0.85, 99% confidence interval 0.65 to 1.11). There was no statistically significant difference in anxiety scores for male participants (mean difference 0.1, 99% confidence interval -2.4 to 2.6) and female participants (mean difference 0.0, 99% confidence interval -2.2 to 2.2) between the arms. The economic analysis showed that freeze-all had a low probability of being cost-effective in terms of the incremental cost per healthy baby and incremental cost per live birth.

LIMITATIONS

We were unable to reach the original planned sample size of 1086 and the rate of non-adherence to the allocated intervention was much higher than expected.

CONCLUSION

When efficacy, safety and costs are considered, freeze-all is not better than fresh-embryo transfer.

TRIAL REGISTRATION

This trial is registered as ISRCTN61225414.

FUNDING

This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 26, No. 25. See the NIHR Journals Library website for further project information.

Maternal and Neonatal Outcomes After Assisted Reproductive Technology: A Retrospective Cohort Study in China

Background

With the progress of assisted reproductive technology (ART) and the increasing number of ART pregnancy, its safety has become the focus of attention. The present study aimed to explore the associations of ART pregnancy with maternal and neonatal outcomes, as compared with naturally pregnancy.

Methods

This retrospective cohort study included all pregnant women who delivered at Women’s Hospital of Nanjing Medical University in 2011–2020. We compared maternal characteristics and pregnancy outcomes between group of ART pregnancy and group of naturally pregnancy using Logistic regression adjusted for confounders.

Results

A total of 13,604 ART pregnancies and 198,002 naturally pregnancies were included. The proportion of ART pregnancies has increased every year for the past 10 years, peaking in 2020 (9.0%). Multivariable logistic regression analysis showed that the risks of gestational diabetes, preeclampsia, moderate or severe anemia, liver-related diseases, thyroid-related diseases, preterm birth, placenta previa, postpartum hemorrhage, and cesarean section were significantly increased in ART pregnancy. For neonatal outcomes, women conceived by ART were more likely to have twins or multiples, and the risk of stillbirth or abnormal development was also significantly increased. When restriction to singletons, these risks were reduced. And the effects of ART on the risk of premature rupture of membrane, cord entanglement, intrapartum fever, cesarean section, and stillbirth or abnormal development were more pronounced in singletons pregnancies compared with that in pregnancies of twins or multiples.

Conclusion

Women conceived by ART were at increased risks of several adverse pregnancy outcomes compared with women conceived naturally. Multiple pregnancies could partly explain this phenomenon. For ART pregnancy, prenatal and intrapartum monitoring should be strengthened, and neonatal outcomes should be closely observed.

Placental Abnormalities are Associated With Specific Windows of Embryo Culture in a Mouse Model

Assisted Reproductive Technologies (ART) employ gamete/embryo handling and culture in vitro to produce offspring. ART pregnancies have an increased risk of low birth weight, abnormal placentation, pregnancy complications, and imprinting disorders. Embryo culture induces low birth weight, abnormal placental morphology, and lower levels of DNA methylation in placentas in a mouse model of ART. Whether preimplantation embryos at specific stages of development are more susceptible to these perturbations remains unresolved. Accordingly, we performed embryo culture for several discrete periods of preimplantation development and following embryo transfer, assessed fetal and placental outcomes at term. We observed a reduction in fetal:placental ratio associated with two distinct windows of preimplantation embryo development, one prior to the morula stage and the other from the morula to blastocyst stage, whereas placental morphological abnormalities and reduced imprinting control region methylation were only associated with culture prior to the morula stage. Extended culture to the blastocyst stage also induces additional placental DNA methylation changes compared to embryos transferred at the morula stage, and female concepti exhibited a higher loss of DNA methylation than males. By identifying specific developmental windows of susceptibility, this study provides a framework to optimize further culture conditions to minimize risks associated with ART pregnancies.

Neurological development in 36‐month‐old children conceived via assisted reproductive technology: The Japan Environment and Children's Study

Purpose

This study aimed to investigate neurodevelopment in children conceived via in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) with several types of embryo transfers.

Methods

We analyzed data for 77 928 children and their mothers included in a Japanese birth cohort study. Among the included children, 4071 were conceived via IVF, while 1542 were conceived via ICSI. Neurodevelopmental delay at the age of 3 years was assessed using the Japanese version of the Ages and Stages Questionnaires, 3rd edition.

Results

In the crude model, the odds ratios for developmental delay in 1–4 domains were higher among children conceived via IVF, ICSI, and non‐ART (ovulatory induction or intrauterine insemination) than in spontaneously conceived children. After adjusting for parental background factors and the child's sex, there were no differences in the risk of developmental delay when comparing singletons conceived by IVF, ICSI, or non‐ART and those conceived spontaneously. Higher odds ratios for developmental delay in one domain were observed in singleton girls conceived via IVF when compared with those who were spontaneously conceived.

Conclusion

Most cases of developmental delay may be associated with multiple pregnancies and factors related to infertility, such as parental age, irrespective of the use of ART.

Obstetric Outcomes and Successful Reduction of Twin Pregnancies Achieved by In Vitro Fertilization

The use of in vitro fertilization methods around the world is constantly increasing. In some developed countries, up to 5% of newborns are as a result of pregnancies after IVF procedures. In vitro fertilization as one of the main and widespread methods for treatment of infertility is the main reason for the high frequency of multiple pregnancies, which, in many countries, is still too high. Most of the multiple pregnancies are in fact twin pregnancies. Twin pregnancies, regardless of how they are achieved, are associated with large number of complications compared with singleton ones. More often these pregnancies can lead to maternal complications and adverse pregnancy outcomes. Maternal complications include development of preeclampsia, gestational diabetes, placenta previa, placental abruption, premature rupture of membranes, antepartum and postpartum hemorrhage, and delivery by cesarean sections. Adverse pregnancy outcomes mostly include preterm birth (PTB), low birth weight (LBW), small for gestational age newborn (SGA), intrauterine growth restriction (IUGR), neonatal respiratory distress syndrome (RDS), and admission to neonatal intensive care unit (NICU). A number of studies have found differences in the course of twin pregnancies according to their mode of occurrence – spontaneous or after IVF. Some of them have found that twin pregnancies after IVF are associated with poorer obstetric and perinatal outcomes, others do not find such a difference, and there are even studies that find a better outcome in IVF twin pregnancies. Twin pregnancy is a common occurrence after IVF procedure, because multiple-embryo transfer is commonly regarded as an effective strategy to improve the likelihood of a successful pregnancy. Understanding the risks of these pregnancies should be a strong motive for the transfer of fewer embryos during IVF procedures. The most effective way to do this is to transfer a single-embryo into the uterus in cases, where this is justified and the chances of getting pregnant are high. An important element in achieving this goal is the use of methods for vitrification of embryos, which leads to a sufficiently high rate of clinical pregnancies after freezing of embryos obtained by IVF and their subsequent transfer after thawing in case of failure of fresh ET.

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.

The role of maternal age on the risk of preterm birth among singletons and multiples: a retrospective cohort study in Lombardy, Norther Italy

Background

All over the world, especially in the developed countries, maternal age at birth is rising. This study aimed to assess the role of maternal age on the occurrence of preterm birth (PTB) in a large birth cohort of Lombardy Region, Northern Italy.

Methods

This population-based study used data from regional healthcare utilization databases of Lombardy to identify women who delivered between 2007 and 2017. PTBs were defined as births before 37 completed weeks of gestation and considered according to the gestational age (two categories: < 32 weeks and 32 to 36 weeks). Six maternal age groups were defined (< 20, 20–24, 25–29, 30–34, 35–39, ≥40 years). Logistic regression models were fitted to estimate the crude and adjusted odds ratio (aOR) and the corresponding 95% confidence interval (CI) for PTB among different maternal age groups. Analyses were separately performed according to type of pregnancy (singletons and multiples). Reference group was the age group with the lowest frequency of PTB.

Results

Overall, 49,759 (6.6%) PTBs were observed, of which 41,807 were singletons and 7952 were multiples. Rates of PTB were lowest in the women aged 25–29 years among singletons and in the 30–34 years old group among multiples. Our results described a U-shaped association between maternal age and risk of PTB. In particular, the risk of a singleton PTB between 32 and 36 weeks was significantly higher for women aged less than 20 years (aOR = 1.16, CI 95%: 1.04–1.30) and more than 40 years (aOR = 1.62 CI 95%: 1.54–1.70). The highest risk of a multiple delivery between 32 and 36 weeks was observed among women aged less than 25 years and more than 40 years (aOR = 1.79, CI 95%: 1.01–3.17, aOR = 1.47, CI 95%: 1.16–1.85 and aOR = 1.36, CI 95%: 1.19–1.55 respectively for < 20, 20–24 and > 40 age categories). PTB before 32 completed weeks occurred more frequently in the same age categories, except that among multiples no association with advanced maternal age emerged.

Conclusion

Our study suggested that, after adjustment for potential confounders, both advance and young maternal age were associated with an increased risk of PTB.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04552-y.

Placental histology and pregnancy complications following intracytoplasmic sperm injection for non-male factor infertility

PURPOSE

To assess obstetric outcomes and placental histology following intracytoplasmic sperm injection (ICSI), for non-male infertility.

METHODS

This was a retrospective cohort of live born singleton deliveries after in vitro fertilization (IVF) at a single university affiliated medical center between 2009 and 2017. Excluded were IVF cycles with male infertility and oocyte recipients. We compared obstetric outcomes and placental histology in cases ICSI was performed (ICSI group) and cases with no ICSI (IVF group).

RESULTS

A total of 400 deliveries following ICSI were compared to 218 in the IVF group. Maternal age was similar between the groups, while diminished ovarian reserve was more common among ICSI patients and tubal disease less common (p < 0.001). The rate of blastocyte transfer was also significantly lower in the ICSI group-67.5% vs. 77%, p = 0.01. Pregnancies following ICSI were characterized by similar rates of preeclampsia, preterm birth, and small for gestational age neonates. Although cesarean delivery rate was significantly higher in the group, this did no attain significance after adjustment for confounders. Placentas in the ICSI group were notable for a lower rate of villitis of unknown etiology (1% vs. 4.5%, p = 0.007) and a higher rate of maternal surface calcifications (33% vs. 23.8%, p = 0.01) after adjustment for confounders.

CONCLUSION

The employment of ICSI with no male indication is associated with similar obstetric outcomes. Despite isolated placental differences among many investigated, placental histology seems overall comparable as well. These results are reassuring to clinicians and patients.

Is there any difference between the obstetric and perinatal complications of pregnancy in patients with and without repeated implantation failure in fresh and frozen-thawed embryo transfer cycles?

Background

Repeated implantation failure (RIF) is the main challenge in assisted reproduction; the present study aimed to compare the obstetric and perinatal outcomes between RIF and control patients who experienced a successful pregnancy after fresh embryo transfer (ET) or frozen-thawed embryo transfer (FET) cycles. Data were obtained from 1150 women experiencing embryo transfer(s), consisting of 720 fresh ET and 430 FET cycles, at the Research and Clinical Center for Infertility, Yazd, Iran. The 370 women, in total, reached chemical pregnancies and finally 321 cases in fresh ET (n=216) and FET (n=105) cycles with singleton deliveries divided into two groups of control and RIF according to the number of last implantation failures. Then, the rate of obstetric and prenatal complications was compared between two groups in fresh ET and FET cycles.

Results

The results showed a higher abortion rate in the RIF group compared to the control group in fresh and FET cycles. In the assessment of the data from the cases with singleton pregnancies in fresh and FET cycles, the results showed almost similar obstetric and perinatal complications in the patients of RIF and control groups. Although the rates of some complications like vaginal bleeding, PROM, preterm delivery, and NICU administration were higher in the RIF patients, these were not significant (P > 0.05).

Conclusion

There was some variation in the normal rates of obstetric and perinatal outcomes between RIF patients compared to control. But, it seems necessary to run studies on more patients to endorse this conclusion.

Clinical outcomes after elective double-embryo transfer in frozen cycles for women of advanced maternal age: A retrospective cohort study

We aimed to determine the clinical outcome of double cleavage-stage embryo transfers in frozen-thawed embryo transfer cycles for older women.This study analyzed a total of 8189 cleavage-stage frozen-thawed embryo transfer cycles between January 2013 and December 2017 at Sir Run Run Shaw Hospital. All cycles were sorted into 3 groups based on patient age: ≤35 years (Group A), 36 to 37 years (Group B), and ≥38 years (Group C). The clinical pregnancy rate (CPR), implantation rate (IR), live birth rate (LBR), miscarriage rate, multiple pregnancy rate (MPR), preterm birth rate, and low-birth-weight rate were compared between the 3 groups.Significant differences in CPR, IR, LBR, MPR, and premature birth rate were found among the 3 groups. The CPR, IR, LBR, and MPR in Group A were higher than those in Group C. Transfers of 2 high-quality embryos resulted in significant differences in CPR, IR, LBR, MPR, and neonatal weight among the 3 groups, but no differences in premature birth and abortion rates were observed. Transfers with 1 high-quality and 1 fair-quality embryo resulted in significant differences in CPR, IR, and LBR among the 3 groups. Comparison of transfers of 2 high-quality embryos with 1 high-quality and 1 fair-quality embryo showed that the CPR and LBR were significantly lower for the latter in Groups A and C, but Group B had no salient changes.Higher IR and LBR and lower MPR may be achieved by selection of optimal embryo types for patients of different ages. Two high-quality embryos need to be transferred in women older than 38 years. For women aged 36 to 37 years, 1 high-quality embryo or 1 high-quality plus 1 fair-quality embryo should be singled out for transfer. For women younger than 35 years, a single high-quality embryo should be selected for transfer.

Elective freezing of embryos versus fresh embryo transfer in IVF: a multicentre randomized controlled trial in the UK (E-Freeze)

STUDY QUESTION

Does a policy of elective freezing of embryos, followed by frozen embryo transfer result in a higher healthy baby rate, after first embryo transfer, when compared with the current policy of transferring fresh embryos?

SUMMARY ANSWER

This study, although limited by sample size, provides no evidence to support the adoption of a routine policy of elective freeze in preference to fresh embryo transfer in order to improve IVF effectiveness in obtaining a healthy baby.

WHAT IS KNOWN ALREADY

The policy of freezing all embryos followed by frozen embryo transfer is associated with a higher live birth rate for high responders but a similar/lower live birth after first embryo transfer and cumulative live birth rate for normal responders. Frozen embryo transfer is associated with a lower risk of ovarian hyperstimulation syndrome (OHSS), preterm delivery and low birthweight babies but a higher risk of large babies and pre-eclampsia. There is also uncertainty about long-term outcomes, hence shifting to a policy of elective freezing for all remains controversial given the delay in treatment and extra costs involved in freezing all embryos.

STUDY DESIGN, SIZE, DURATION

A pragmatic two-arm parallel randomized controlled trial (E-Freeze) was conducted across 18 clinics in the UK from 2016 to 2019. A total of 619 couples were randomized (309 to elective freeze/310 to fresh). The primary outcome was a healthy baby after first embryo transfer (term, singleton live birth with appropriate weight for gestation); secondary outcomes included OHSS, live birth, clinical pregnancy, pregnancy complications and cost-effectiveness.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Couples undergoing their first, second or third cycle of IVF/ICSI treatment, with at least three good quality embryos on Day 3 where the female partner was ≥18 and <42 years of age were eligible. Those using donor gametes, undergoing preimplantation genetic testing or planning to freeze all their embryos were excluded. IVF/ICSI treatment was carried out according to local protocols. Women were followed up for pregnancy outcome after first embryo transfer following randomization.

MAIN RESULTS AND THE ROLE OF CHANCE

Of the 619 couples randomized, 307 and 309 couples in the elective freeze and fresh transfer arms, respectively, were included in the primary analysis. There was no evidence of a statistically significant difference in outcomes in the elective freeze group compared to the fresh embryo transfer group: healthy baby rate {20.3% (62/307) versus 24.4% (75/309); risk ratio (RR), 95% CI: 0.84, 0.62 to 1.15}; OHSS (3.6% versus 8.1%; RR, 99% CI: 0.44, 0.15 to 1.30); live birth rate (28.3% versus 34.3%; RR, 99% CI 0.83, 0.65 to 1.06); and miscarriage (14.3% versus 12.9%; RR, 99% CI: 1.09, 0.72 to 1.66). Adherence to allocation was poor in the elective freeze group. The elective freeze approach was more costly and was unlikely to be cost-effective in a UK National Health Service context.

LIMITATIONS, REASONS FOR CAUTION

We have only reported on first embryo transfer after randomization; data on the cumulative live birth rate requires further follow-up. Planned target sample size was not obtained and the non-adherence to allocation rate was high among couples in the elective freeze arm owing to patient preference for fresh embryo transfer, but an analysis which took non-adherence into account showed similar results.

WIDER IMPLICATIONS OF THE FINDINGS

Results from the E-Freeze trial do not lend support to the policy of electively freezing all for everyone, taking both efficacy, safety and costs considerations into account. This method should only be adopted if there is a definite clinical indication.

STUDY FUNDING/COMPETING INTEREST(S)

NIHR Health Technology Assessment programme (13/115/82). This research was funded by the National Institute for Health Research (NIHR) (NIHR unique award identifier) using UK aid from the UK Government to support global health research. The views expressed in this publication are those of the author(s) and not necessarily those of the NIHR or the UK Department of Health and Social Care. J.L.B., C.C., E.J., P.H., J.J.K., L.L. and G.S. report receipt of funding from NIHR, during the conduct of the study. J.L.B., E.J., P.H., K.S. and L.L. report receipt of funding from NIHR, during the conduct of the study and outside the submitted work. A.M. reports grants from NIHR personal fees from Merck Serono, personal fees for lectures from Merck Serono, Ferring and Cooks outside the submitted work; travel/meeting support from Ferring and Pharmasure and participation in a Ferring advisory board. S.B. reports receipt of royalties and licenses from Cambridge University Press, a board membership role for NHS Grampian and other financial or non-financial interests related to his roles as Editor-in-Chief of Human Reproduction Open and Editor and Contributing Author of Reproductive Medicine for the MRCOG, Cambridge University Press. D.B. reports grants from NIHR, during the conduct of the study; grants from European Commission, grants from Diabetes UK, grants from NIHR, grants from ESHRE, grants from MRC, outside the submitted work. Y.C. reports speaker fees from Merck Serono, and advisory board role for Merck Serono and shares in Complete Fertility. P.H. reports membership of the HTA Commissioning Committee. E.J. reports membership of the NHS England and NIHR Partnership Programme, membership of five Data Monitoring Committees (Chair of two), membership of six Trial Steering Committees (Chair of four), membership of the Northern Ireland Clinical Trials Unit Advisory Group and Chair of the board of Oxford Brain Health Clinical Trials Unit. R.M. reports consulting fees from Gedeon Richter, honorarium from Merck, support fees for attendance at educational events and conferences for Merck, Ferring, Bessins and Gedeon Richter, payments for participation on a Merck Safety or Advisory Board, Chair of the British Fertility Society and payments for an advisory role to the Human Fertilisation and Embryology Authority. G.S. reports travel and accommodation fees for attendance at a health economic advisory board from Merck KGaA, Darmstadt, Germany. N.R.-F. reports shares in Nurture Fertility. Other authors' competing interests: none declared.

TRIAL REGISTRATION NUMBER

ISRCTN: 61225414.

TRIAL REGISTRATION DATE

29 December 2015.

DATE OF FIRST PATIENT’S ENROLMENT

16 February 2016.

Society for Maternal-Fetal Medicine Consult Series #60: Management of pregnancies resulting from in vitro fertilization

The use of assisted reproductive technology has increased in the United States in the past several decades. Although most of these pregnancies are uncomplicated, in vitro fertilization is associated with an increased risk for adverse perinatal outcomes primarily caused by the increased risks of prematurity and low birthweight associated with in vitro fertilization pregnancies. This Consult discusses the management of pregnancies achieved with in vitro fertilization and provides recommendations based on the available evidence. The recommendations by the Society for Maternal-Fetal Medicine are as follows: (1) we suggest that genetic counseling be offered to all patients undergoing or who have undergone in vitro fertilization with or without intracytoplasmic sperm injection (GRADE 2C); (2) regardless of whether preimplantation genetic testing has been performed, we recommend that all patients who have achieved pregnancy with in vitro fertilization be offered the options of prenatal genetic screening and diagnostic testing via chorionic villus sampling or amniocentesis (GRADE 1C); (3) we recommend that the accuracy of first-trimester screening tests, including cell-free DNA for aneuploidy, be discussed with patients undergoing or who have undergone in vitro fertilization (GRADE 1A); (4) when multifetal pregnancies do occur, we recommend that counseling be offered regarding the option of multifetal pregnancy reduction (GRADE 1C); (5) we recommend that a detailed obstetrical ultrasound examination (CPT 76811) be performed for pregnancies achieved with in vitro fertilization and intracytoplasmic sperm injection (GRADE 1B); (6) we suggest that fetal echocardiography be offered to patients with pregnancies achieved with in vitro fertilization and intracytoplasmic sperm injection (GRADE 2C); (7) we recommend that a careful examination of the placental location, placental shape, and cord insertion site be performed at the time of the detailed fetal anatomy ultrasound, including evaluation for vasa previa (GRADE 1B); (8) although visualization of the cervix at the 18 0/7 to 22 6/7 weeks of gestation anatomy assessment with either a transabdominal or endovaginal approach is recommended, we do not recommend serial cervical length assessment as a routine practice for pregnancies achieved with in vitro fertilization (GRADE 1C); (9) we suggest that an assessment of fetal growth be performed in the third trimester for pregnancies achieved with in vitro fertilization; however, serial growth ultrasounds are not recommended for the sole indication of in vitro fertilization (GRADE 2B); (10) we do not recommend low-dose aspirin for patients with pregnancies achieved with IVF as the sole indication for preeclampsia prophylaxis; however, if 1 or more additional risk factors are present, low-dose aspirin is recommended (GRADE 1B); (11) given the increased risk for stillbirth, we suggest weekly antenatal fetal surveillance beginning by 36 0/7 weeks of gestation for pregnancies achieved with in vitro fertilization (GRADE 2C); (12) in the absence of studies focused specifically on timing of delivery for pregnancies achieved with IVF, we recommend shared decision-making between patients and healthcare providers when considering induction of labor at 39 weeks of gestation (GRADE 1C).

Obstetric outcomes of young women following in-vitro fertilization: a case-control study

BACKGROUND

Women undergoing in-vitro fertilization (IVF) treatments are at increased risk for maternal and neonatal complications compared to women who conceive spontaneously. Though spontaneous pregnancies of young women and adolescents have an increased risk for adverse maternal and neonatal outcomes, pregnancy outcomes of this age group, following IVF treatment have been scarcely reported. The aim of this study was to report maternal and neonatal outcomes of young women who conceived following IVF compared to women in the same age group with spontaneous conception.

METHODS

We performed a multicenter case-control study. The study group included women aged 17-25 years who conceived by IVF with an ongoing singleton pregnancy. For the purpose of the study, a control group matched (1:2 ratio) for maternal age at delivery and parity was constructed. Demographic, medical history, pregnancy related characteristics and maternal and neonatal outcomes were compared between groups. Finally, factors associated with spontaneous vaginal delivery were assessed for the entire cohort using a univariate and multivariate logistic regression model.

RESULTS

Between 2005 and 2021, we identified 80 women aged 19-25 years who conceived by IVF. A control group of 160 women was matched to the study group by age and parity. The unmatched maternal characteristics and pregnancy associated complications were similar among the groups. However, the IVF group had a significantly higher rate of induction of labor (48.1% vs. 26.6%, p = 0.001), meconium-stained amniotic fluid (27.6% vs. 14.1%, p = 0.025), prolonged second stage of labor (26.0% vs. 7.3%, p = 0.001) and operative vaginal delivery (22.5% vs.12.5%, p = 0.048). Neonatal outcomes were for the most part comparable; nevertheless, we found a higher rate of neonates with an umbilical artery pH < 7.1 in the IVF group (9.8% vs. 0.0%, respectively; p = 0.022). A logistic regression analysis for spontaneous vaginal delivery (vs. cesarean or operative vaginal deliveries) found that spontaneous onset of labor (vs. induction of labor) (OR = 2.08; 95% CI = 1.07-4.05, p = 0.03) was positively associated with spontaneous vaginal delivery while prolonged second stage of labor (OR = 0.35; 95% CI = 0.13-0.95, p = 0.04) was negatively associated with this parameter.

CONCLUSION

Young women who conceive by in-vitro fertilization are expected to reach favorable pregnancy outcomes, comparable to women who conceived spontaneously.

In-Hospital Complications in Pregnancies Conceived by Assisted Reproductive Technology

Background Assisted reproductive technology (ART) has emerged as a common treatment option for infertility, a problem that affects an estimated 48 million couples worldwide. Advancing maternal age with increasing prepregnancy cardiovascular risk factors, such as chronic hypertension, obesity, and diabetes, has raised concerns about pregnancy complications associated with ART. However, in-hospital complications following pregnancies conceived by ART are poorly described. Methods and Results To assess the patient characteristics, obstetric outcomes, vascular complications and temporal trends of pregnancies conceived by ART, we analyzed hospital deliveries conceived with or without ART between January 1, 2008, and December 31, 2016, from the United States National Inpatient Sample database. We included 106 248 deliveries conceived with ART and 34 167 246 deliveries conceived without ART. Women who conceived with ART were older (35 versus 28 years; P<0.0001) and had more comorbidities. ART-conceived pregnancies were independently associated with vascular complications (acute kidney injury: adjusted odds ratio [aOR], 2.52; 95% CI 1.99-3.19; and arrhythmia: aOR, 1.65; 95% CI, 1.46-1.86), and adverse obstetric outcomes (placental abruption: aOR, 1.57; 95% CI, 1.41-1.74; cesarean delivery: aOR, 1.38; 95% CI, 1.33-1.43; and preterm birth: aOR, 1.26; 95% CI, 1.20-1.32), including in subgroups without cardiovascular disease risk factors or without multifetal pregnancies. Higher hospital charges ($18 705 versus $11 983; P<0.0001) were incurred compared with women who conceived without ART. Conclusions Pregnancies conceived by ART have higher risks of adverse obstetric outcomes and vascular complications compared with spontaneous conception. Clinicians should have detailed discussions on the associated complications of ART in women during prepregnancy counseling.

Critical Care in SARS-CoV-2 Infected Pregnant Women: A Prospective Multicenter Study

Evidence suggests that pregnant women are at a higher risk of complications compared to the general population when infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the reasons that lead them to need intensive care are not clear. This is a prospective multicenter study of SARS-CoV-2 positive pregnant women, registered by the Spanish Obstetric Emergency Group, with the objective to define the characteristics of the mothers who were admitted to the Intensive Care Unit (ICU) and to investigate the causes and risk factors for ICU admission. A total of 1347 infected pregnant women were registered and analyzed, of whom, 35 (2.6%) were admitted to the ICU. No differences in maternal characteristics or comorbidities were observed between ICU and non-ICU patients, except for in vitro fertilization and multiple pregnancies. The main causes of admission to the ICU were non-obstetric causes (worsening of the maternal condition and respiratory failure due to SARS-CoV-2 pneumonia, 40%) and a combination of coronavirus disease 2019 (COVID-19) symptoms and obstetrical complications (31.4%). The multivariable logistic analysis confirmed a higher risk of ICU admission when pre-eclampsia or hemorrhagic events coexist with pneumonia. The incidence of thromboembolic events and disseminated intravascular coagulation were also significantly higher among patients admitted to the ICU. Therefore, surveillance and rapid intervention should be intensified in SARS-CoV-2 infected pregnant women with the mentioned risk factors and complications. Emphasis should always be placed on anticoagulant therapy in these patients due to the increased thromboembolic risk, C-section surgery and immobilization in the ICU.

Impact of Maternal Age on Singleton Pregnancy Outcomes in Primiparous Women in South Korea

We aimed to determine the association between maternal age and pregnancy outcomes in singleton primigravidae in South Korea. We reviewed the medical data of singleton primigravidae women who gave birth between 2013 and 2018 and underwent the National Health Screening Examination using the administrative database from the National Health Insurance claims data. As advanced maternal age is associated with various comorbidities that could affect pregnancy outcomes, we divided the patients according to their age and comparatively analyzed the prevalence of high-risk pregnancy complications including rates of cesarean delivery, after adjusting for maternal demographics. Perinatal and postpartum complications according to maternal age were also investigated. Overall, 548,080 women were included in this study: 441,902 were aged <35 years; 85,663, 35–39 years; 20,515, ≥40 years. Patients’ demographics differed according to their age. Increasing maternal age was significantly associated with higher income levels and higher rates of obesity, pre-existing diabetes, and hypertension. With the increasing maternal age, the rate of obstetric complications, including gestational diabetes, preeclampsia, placenta previa, placental abruption, and cesarean delivery, increased. Maternal age was also positively correlated with perinatal morbidity including preterm birth and low birth weight. Additionally, advanced maternal age was a risk factor for hospitalization before delivery, more frequent outpatient visits, and readmission after delivery. These observations were maintained in the multivariate analysis results. Advanced maternal age appears to be associated with various adverse obstetric outcomes for primigravidae women, and the frequency of hospitalizations was higher in this group. Considering the current social environment of late pregnancies and childbirth in South Korea, effective policy consideration is required to support safe childbirth in women with advanced maternal age.

Reproductive function in men conceived with in vitro fertilization and intracytoplasmic sperm injection

OBJECTIVE

To determine the semen quality and reproductive hormones of men conceived by in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) compared with men conceived without assisted reproductive technology (ART).

DESIGN

Cohort study.

SETTING

IVF centers in Victoria and the Western Australian Raine Study.

PATIENT(S)

Men conceived with IVF/ICSI and men conceived without ART aged 18-25 years.

INTERVENTION(S)

Clinical review.

MAIN OUTCOME MEASURE(S)

The primary outcome was the prevalence of severe oligozoospermia (sperm concentration, <5 million/mL). The secondary outcomes were total sperm count, total and progressive motility, total motile count, normal morphology, and serum testosterone, luteinizing hormone (LH) and follicle-stimulating hormone (FSH).

RESULTS

There was no difference in the prevalence of severe oligozoospermia between 120 men conceived with IVF/ICSI and 356 men conceived without ART (9% vs. 5.3%). Men conceived with IVF/ICSI had similar sperm concentration, total sperm count, and total motile count but lower mean total (55.3% vs. 60.6%) and progressive (44.7% vs. 53.9%) sperm motility with higher mean normal morphology (8.5% vs. 5.4%). Differences in progressive motility (ß, -9.9; 95% confidence interval [CI], -16.7 - -3.0), normal morphology (ß, 4.3; 95% CI, 3.0-5.7), and proportion with abnormal morphology (adjusted odds ratios, 0.1; 95% CI, 0.04-0.5) remained significant after adjusting for confounders. Men conceived with IVF/ICSI had lower mean FSH (3.3 IU/L) and LH (3.9 IU/L) levels and higher mean testosterone levels (19.1 nmol/L) than controls (4.2 IU/L, 11.0 IU/L, and 16.8 nmol/L).

CONCLUSION

This study of men conceived with IVF/ICSI found similar sperm output to men conceived without ART. Overall, the results are reassuring.

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.

Live birth, cumulative live birth and perinatal outcome following assisted reproductive treatments using donor sperm in single women vs. women in lesbian couples: a prospective controlled cohort study

Purpose

Assisted reproductive technology (ART) treatments with donor sperm have been allowed for women in lesbian relationships (WLR) since 2005 in Sweden, but for single women (SW), these became approved only recently in 2016. This study was conducted to compare the outcomes of ART treatments in SW vs. WLR.

Methods

This is a prospective controlled cohort study of 251 women undergoing intrauterine insemination (D-IUI) or in vitro fertilization (D-IVF) using donor sperm between 2017 and 2019 at the department of Reproductive Medicine, Karolinska University Hospital. The cohort comprised 139 SW and 112 WLR. The main outcomes included differences in live birth rate (LBR) and cumulative live birth rate (cLBR) between the groups. The SW underwent 66 D-IUI and 193 D-IVF treatments and WLR underwent 255 D-IUI and 69 D-IVF treatments. Data on clinical characteristics, treatment protocols and clinical outcomes were extracted from the clinic’s electronic database. The outcomes of D-IUI and D-IVF were separately assessed.

Results

The cohort of SW was significantly older than WLR (37.6 vs. 32.4 years, P < 0.001), and more commonly underwent IVF at first treatment (83% vs. 29%, P < 0.000). Conversely, WLR underwent more frequently D-IUI as a first treatment (71% vs. 17% of SW, P < 0.001) and more often in the natural cycle (89.9% vs. 70.8%, P = 0.019), respectively. There was no statistically significant difference in the main outcome LBR between the two groups, or between the two different types of treatment, when adjusted for age. Perinatal outcomes and cLBR were also similar among the groups.

Conclusions

SW were, on average, older than WLR undergoing treatment with donor sperm. No significant differences were seen in the LBR and cLBR when adjusted for age between the two groups and between the two types of treatment (D-IVF vs. D-IUI).

Trial registration

ClinicalTrials.gov NTC04602962.

Medically Assisted Reproduction Treatment Types and Birth Outcomes

Medically assisted reproduction treatments are associated with adverse birth outcomes; however, those risks are unlikely to be associated with the infertility treatments themselves.

OBJECTIVE:

To compare risks of adverse birth outcomes among pregnancies conceived with and without medically assisted reproduction treatments.

METHODS:

Birth certificates were used to study birth outcomes of all neonates born in Utah from 2009 through 2017. Of the 469,919 deliveries, 52.8% (N=248,013) were included in the sample, with 5.2% of the neonates conceived through medically assisted reproduction. The outcome measures included birth weight, gestational age, low birth weight (LBW, less than 2,500 g), preterm birth (less than 37 weeks of gestation), and small for gestational age (SGA, birth weight less than the 10th percentile). Linear models were estimated for the continuous outcomes (birth weight, gestational age), and linear probability models were used for the binary outcomes (LBW, preterm birth, SGA). First, we compared the birth outcomes of neonates born after medically assisted reproduction and natural conception in the overall sample (between-family analyses), before and after adjustment for parental background and neonatal characteristics. Second, we employed family fixed effect models to investigate whether the birth outcomes of neonates conceived through medically assisted reproduction differed from those of their naturally conceived siblings (within-family comparisons).

RESULTS:

Neonates conceived through medically assisted reproduction weighed less, were born earlier, and were more likely to be LBW, preterm, and SGA than neonates conceived naturally. More invasive treatments (assisted reproductive technology [ART] and artificial insemination [AI] or intrauterine insemination) were associated with worse birth outcomes; for example, the proportion of LBW and preterm birth was 6.1% and 7.9% among neonates conceived naturally and 25.5% and 29.8% among neonates conceived through ART, respectively. After adjustments for various neonatal and parental characteristics, the differences in birth outcomes between neonates conceived through medically assisted reproduction and naturally were attenuated yet remained statistically significant; for example, neonates conceived through ART were at 3.2 percentage points higher risk for LBW (95% CI 2.4–4.1) and 4.8 percentage points higher risk for preterm birth (95% CI 3.9–5.7). Among siblings, the differences in the frequency of adverse outcomes between neonates conceived through medically assisted reproduction and neonates conceived naturally were small and statistically insignificant for all types of treatments.

CONCLUSION:

Medically assisted reproduction treatments are associated with adverse birth outcomes; however, those risks are unlikely to be associated with the infertility treatments itself.

Use of reproductive technology for sex selection for nonmedical reasons: an Ethics Committee opinion

Because the practice of preimplantation sex selection is ethically controversial, clinics are encouraged to develop and make available their policies regarding its use. Practitioners offering assisted reproductive services are under no ethical obligation to provide or refuse to provide nonmedically-indicated methods of sex selection. This document replaces the document of the same name, last published in 2015.

Maternal advanced age, single parenthood, and ART increase the risk of child morbidity up to five years of age

Background

Advanced maternal age, single status and use of assisted reproductive technology (ART) are increasing in mothers in high-income countries, and all are known risk factors for negative obstetric outcomes. Less is known about their long-term consequences for childhood morbidity. Thus, the aim of this study was to investigate morbidity up to five years of age, in the children of older, single, and/or ART-treated mothers.

Methods

A cross-sectional using Swedish registers was performed comprising 23 772 children. The prevalence of diagnosis and the number of hospital visits for specialist care, were compared and analyzed in relation to maternal age at childbirth, maternal civil status, and mode of conception. The odds ratio for specialized care within each ICD-chapter were estimated using single and multiple logistic regression.

Results

Children born to single mothers and children conceived using ART had significantly more outpatient visits for specialist care and significantly more diagnoses compared to children with married/cohabiting mothers, and spontaneously conceived children. Children born to mothers of advanced maternal age (≥40) had fewer in- and outpatient visits. However, they were significantly more often diagnosed within ICD-chapters XVI, XVII i.e., they experienced more morbidity in the neonatal period.

Conclusion

The results indicate that children born to single mothers and children of ART-treated mothers have a higher morbidity and consume more specialist care than children of married/cohabiting and spontaneously pregnant mothers. We conclude that the use of ART, maternal single status and advanced maternal age are risk factors of importance to consider in pediatric care and when counseling women who are considering ART treatment.

Placental Dysfunction in Assisted Reproductive Pregnancies: Perinatal, Neonatal and Adult Life Outcomes

Obstetric and newborn outcomes of assisted reproductive technology (ART) pregnancies are associated with significative prevalence of maternal and neonatal adverse health conditions, such as cardiovascular and metabolic diseases. These data are interpreted as anomalies in placentation involving a dysregulation of several molecular factors and pathways. It is not clear which extent of the observed placental alterations are the result of ART and which originate from infertility itself. These two aspects probably act synergically for the final obstetric risk. Data show that mechanisms of inappropriate trophoblast invasion and consequent altered vascular remodeling sustain several clinical conditions, leading to obstetric and perinatal risks often found in ART pregnancies, such as preeclampsia, fetal growth restriction and placenta previa or accreta. The roles of factors such as VEGF, GATA3, PIGF, sFLT-1, sEndoglin, EGFL7, melatonin and of ART conditions, such as short or long embryo cultures, trophectoderm biopsy, embryo cryopreservation, and supraphysiologic endometrium preparation, are discussed. Inflammatory local conditions and epigenetic influence on embryos of ART procedures are important research topics since they may have important consequences on obstetric risk. Prevention and treatment of these conditions represent new frontiers for clinicians and biologists involved in ART, and synergic actions with researchers at molecular levels are advocated.

Comparing maternal outcomes in spontaneous singleton pregnancies versus in vitro fertilization conception: Single-center 10-year cohort study

OBJECTIVE

A successful assisted reproductive technique (ART) cycle is not flawless, and several studies have reported high incidences of maternal complications, but the association is inconclusive. In addition, the racial and ethnic effects of the Asian population undergoing ART on maternal outcomes is not well studied. This study attempts to compare various maternal outcome parameters ART and spontaneously conceived singleton pregnancies from a single high volume tertiary care centre.

METHODS

A retrospective cohort study from a single tertiary infertility center was conducted from January 2011 to September 2020. The study included 1125 IVF conceived singletons (AP group) and 7193 spontaneous conceived singletons (SP group). The groups were compared using the Pearson Chi-square test and the adjusted odds ratio calculated using multivariate analysis.

RESULTS

Maternal outcomes like gestational hypertension, pre-eclampsia, gestational diabetes (GDM), oligohydramnios, chorioamnionitis, operative, and instrumental delivery were significantly different in the two groups (p<0.05). The AP group had a significantly increased risk of GDM (aOR 1.093; 95% CI 1.076-1.110) and pregnancy-induced hypertension (PIH) (aOR 1.577; 95% CI 1.288-1.930) as compared to the SP group. IVF significantly increases the risk of abruption by 2 times (p=0.028), and independently increases the risk of caesarean section by 3.1-fold (p<0.001). But overall the IVF is the protective factor for oligohydramnios (p=0.024).

CONCLUSIONS

ART increases the likelihood of pregnancy-related maternal complications, such as PIH, GDM, abruption, chorioamnionitis, and an increased rate of caesarean delivery. Thus, all patients undergoing ART procedures should receive pre-conceptional counselling regarding the associated obstetric risks and consider ART pregnancy as a high-risk pregnancy.

OUP accepted manuscript

STUDY QUESTION

Are there differences in thyroid function between adolescents and young adults conceived with and without ART?

SUMMARY ANSWER

This study demonstrated no evidence of clinically relevant differences in thyroid function between adolescents and young adults conceived with and without ART.

WHAT IS KNOWN ALREADY

Studies to date have reported an increase in subclinical hypothyroidism in offspring conceived after ART. It has been suggested that the increase in maternal estrogen (E2) after fresh embryo transfers could affect thyroid function of the offspring. Suboptimal thyroid function at a young age can cause irreversible damage to the central nervous system, which makes early detection and correct treatment essential.

STUDY DESIGN, SIZE, DURATION

The Growing Up Healthy Study (GUHS) is a prospective cohort study, which aimed to recruit all adolescents born after conception with ART between 1991 and 2001 in the study area. The included participants (n = 303, aged 13–20 years) completed various health assessments. Depending on the age at enrolment, participants completed thyroid assessments at the 14- or 20-year follow-up. The outcomes of these replicated thyroid assessments were compared to those of participants conceived without ART from the Raine Study Generation 2 (Gen2). The Gen2 participants (n = 2868) were born between 1989 and 1992 and have been recognized to be representative of the local population.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Thyroid function assessments were compared between n = 134 GUHS and n = 1359 Gen2 adolescents at age 14 years and between n = 47 GUHS and n = 914 Gen2 young adults at age 20 years. The following mean thyroid hormone concentrations were compared between the cohorts: thyroid-stimulating hormone (TSH), free triiodothyronine (fT3), free thyroxine (fT4) and thyroid peroxidase antibodies (TPOAb). The prevalence of the following thyroid hormone profiles, based on individual thyroid hormone concentrations, was compared: euthyroidism, subclinical and overt hypo- and hyperthyroidism and thyroid autoimmunity. Outcomes were compared between the cohorts, and univariately between fresh embryo transfers (ET) and frozen ET (FET) within the GUHS. The correlation between maternal peak E2 concentrations (pE2) and fT4 was assessed within the GUHS.

MAIN RESULTS AND THE ROLE OF CHANCE

All mean thyroid function outcomes fell within the normal range. At both ages, we report no differences in TSH concentrations. At age 14 years, lower fT3 concentrations (4.80 versus 5.35 pmol/L, P < 0.001) and higher fT4 concentrations (12.76 versus 12.19 pmol/L, P < 0.001) were detected in the GUHS adolescents compared to Gen2 adolescents. At age 20 years, higher fT3 and fT4 concentrations were reported in GUHS adolescents (4.91 versus 4.63 pmol/L, P = 0.012; 13.43 versus 12.45 pmol/L, P < 0.001, respectively) compared to Gen2 participants. No differences in the prevalence of subclinical and overt hypo- and hyperthyroidism or thyroid autoimmunity were demonstrated between the cohorts at age 14 and 20 years. Thyroid function did not differ between ET and FET, and no correlation between pE2 and fT4 was reported.

LIMITATIONS, REASONS FOR CAUTION

The observational nature of the study limits the ability to prove causation. Furthermore, the comparison of ET and FET offspring at age 20 years may be lacking power. We were unable to differentiate between different types of ART (e.g. IVF versus ICSI) owing to the low number of ICSI cycles at the time of study. As ART laboratory and clinic data were collected contemporaneously with the time of treatment, no other data pertaining to the ART cycles were sought retrospectively; hence, some factors could not be accounted for.

WIDER IMPLICATIONS OF THE FINDINGS

This study does not support previous findings of clinically relevant differences in thyroid function when comparing a cohort of adolescents conceived after ART to counterparts conceived without ART. The minor differences detected in fT3 and fT4 were considered not biologically relevant. Although these findings appear reassuring, they warrant reinvestigation in adulthood.

STUDY FUNDING/COMPETING INTERESTS

This project was funded by an NHMRC Grant (Hart et al., ID 1042269). R.J.H. is the Medical Director of Fertility Specialists of Western Australia and a shareholder in Western IVF. He has received educational sponsorship from MSD, Merck-Serono and Ferring Pharmaceuticals. P.B. is the Scientific Director of Concept Fertility Centre, Subiaco, Western Australia. J.L.Y. is the Medical Director and a shareholder of PIVET Medical Centre, Perth, Western Australia.

TRIAL REGISTRATION NUMBER

N/A.

Comparison of outcomes of monochorionic twin pregnancies conceived by assisted reproductive technology vs. spontaneous conceptions: A systematic review and meta-analysis

BACKGROUND

This review aimed to assess if monochorionic twin pregnancies conceived by assisted conception have worse maternal and neonatal outcomes as compared to those conceived naturally.

METHODS

Datasets of PubMed, ScienceDirect, CENTRAL, Embase, and Google Scholar were searched for studies comparing maternal and neonatal outcomes of monochorionic twin pregnancies conceived by assisted vs. spontaneous methods.

RESULTS

Eight studies comparing 337 assisted with 2,711 spontaneously conceived monochorionic twin pregnancies were included. Meta-analysis revealed that the mode of conception of monochorionic twin pregnancies had no impact on the risk of hypertensive disorders of pregnancy (HDP) (OR: 1.36 95% CI, 0.73, 2.54 I ² = 9% p = 0.03), twin-twin transfusion syndrome (TTTS) (OR: 0.83 95% CI, 0.52, 1.31 I ² = 0% p = 0.42), and very preterm delivery (OR: 1.18 95% CI, 0.74, 1.88 I ² = 41% p = 0.49). We noted no statistically significant difference in the mean birth weights (MD: -17.66 95% CI, -157.23, 121.91 I ² = 82% p = 0.80), risk of intra-uterine death (OR: 0.90 95% CI, 0.51, 1.60 I ² = 36% p = 0.73) and small for gestational age between the two groups (OR: 0.92 95% CI, 0.67, 1.26 I ² = 0% p = 0.59). There was an increased risk of caesarean sections (OR: 1.34 95% CI, 1.00, 1.80 I ² = 0% p = 0.05) and neonatal death with assisted conceptions as compared to spontaneous conceptions (OR: 2.35 95% CI, 1.11, 5.01 I ² = 37% p = 0.03).

CONCLUSION

Monochorionic twin pregnancies conceived via assisted reproductive technology have a heightened risk of cesarean section and neonatal deaths. However, there is a need for further studies to supplement current evidence.Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=325133, identifier: CRD42022325133.

Retrospective comparison of pregnancy outcomes of fresh and frozen-warmed single blastocyst transfer: a 5-year single-center experience

PURPOSE

To assess whether live birth rates (LBR) and maternal/neonatal complications differed following single fresh and frozen-warmed blastocyst transfer.

METHODS

The present retrospective observational study analyzed 4,613 single embryo transfers (SET) (646 fresh and 3,967 frozen) from January 1, 2014, to December 31, 2018. Fresh embryo transfer at blastocyst stage was considered according to the age of the patient and her prognosis. In case of the risk of ovarian hyperstimulation syndrome, premature progesterone rise, non-optimal endometrial growth, or supernumerary embryos, cryopreservation with subsequent frozen embryo transfer (FET) was indicated.

RESULTS

No differences in LBR were recorded. Fresh embryo transfers yielded an increase both in neonatal complications OR 2.15 (95% CI 1.20-3.86, p 0.010), with a higher prevalence of singletons weighting below the 5th percentile (p 0.013) and of intrauterine growth retardation (p 0.015), as well as maternal complications, with a higher placenta previa occurrence OR 3.58 (95% CI 1.54-8.28, p 0.003), compared to FET.

CONCLUSION

LBR appears not to be affected by the transfer procedure preferred. Fresh embryo transfer is associated with higher risk of neonatal complications (specifically a higher prevalence of singletons weighting below the 5th percentile and of intrauterine growth retardation) and placenta previa. Reflecting on the increased practice of ART procedures, it is imperative to understand whether a transfer procedure yields less complications than the other and if it is time to switch to a "freeze-all" procedure as standard practice.

TRIAL REGISTRATION

Clinical Trial Registration Number: NCT04310761. Date of registration: March 17, 2020, retrospectively registered.

Assisted Reproductive Technology Treatment, the Catalyst to Amplify the Effect of Maternal Infertility on Preterm Birth

OBJECTIVE

To identify the influence of different infertility causes and assisted reproductive technology (ART) treatment on perinatal outcomes and clarify the relationship between the maternal pathophysiological changes and artificial interventions.

METHODS

A total of 1,629 fertile women and 27,112 infertile women with sole infertility causes were prospectively recruited from July 2014 to December 2017, and 9,894 singletons were finally enrolled into the study. Pregnancies with more than one cause of infertility and/or multiple births were excluded. According to the causes of infertility and the exposure of ART treatment, the participants were divided into four groups, namely, fertile naturally conceived (NC) group, infertile NC group, female factor ART group, and male factor ART group. Perinatal outcomes, including gestational age of delivery (GA), birth weight (BW), preterm birth (PTB), low birth weight (LBW), small for gestational age (SGA), and large for gestational age (LGA), were compared among groups. Logistic regression was performed for the adjustment of several covariates.

RESULTS

The birth outcomes of the infertile NC group and fertile NC group, female factor ART group, and infertile NC group were comparable. Compared to the fertile NC group, the female factor ART group had a shorter GA (39.0 ± 1.6 vs. 39.3 ± 1.5 weeks, BW: P < 0.05). An interaction test showed that ART treatment had an interaction on the effect of female infertility on GA (P = 0.023). The female factor ART group also had a higher risk of PTB (OR 1.56, 95% CI 1.18-2.07) and LGA (OR 1.27, 95% CI 1.10-1.47) compared to the fertile NC group. The risk of PTB was increased for tubal factor ART (OR 1.49, 95% CI 1.12-2.00), ovulatory dysfunction ART (OR 1.87, 95% CI 1.29-2.72), and unexplained infertility ART (OR 1.88, 95% CI 1.11-3.17). The risk of LGA was increased for tubal factor ART (OR 1.28, 95% CI 1.11-1.48) and ovulatory dysfunction ART (OR 1.27, 95% CI 1.03-1.57).

CONCLUSIONS

Our findings indicated that ART treatment could amplify the adverse effect of female infertility on neonates. Women with tubal factor infertility, ovulatory dysfunction, and unexplained infertility have a higher risk of PTB after ART treatment. Thus, clinicians should be vigilant in such patients and provide corresponding prevention strategies before and during pregnancy.

Placental Abnormalities and Placenta-Related Complications Following In-Vitro Fertilization: Based on National Hospitalized Data in China

INTRODUCTION

Emerging evidence has shown that in-vitro fertilization (IVF) is associated with higher risks of certain placental abnormalities or complications, such as placental abruption, preeclampsia, and preterm birth. However, there is a lack of large population-based analysis focusing on placental abnormalities or complications following IVF treatment. This study aimed to estimate the absolute risk of placental abnormalities or complications during IVF-conceived pregnancy.

METHODS

We conducted a retrospective cohort study of 16 535 852 singleton pregnancies with delivery outcomes in China between 2013 and 2018, based on the Hospital Quality Monitoring System databases. Main outcomes included placental abnormalities (placenta previa, placental abruption, placenta accrete, and abnormal morphology of placenta) and placenta-related complications (gestational hypertension, preeclampsia, eclampsia, preterm birth, fetal distress, and fetal growth restriction (FGR)). Poisson regression modeling with restricted cubic splines of exact maternal age was used to estimate the absolute risk in both the IVF and non-IVF groups.

RESULTS

The IVF group (n = 183 059) was more likely than the non-IVF group (n = 16 352 793) to present placenta previa (aRR: 1.87 [1.83-1.91]), placental abruption (aRR: 1.16 [1.11-1.21]), placenta accrete (aRR: 2.00 [1.96-2.04]), abnormal morphology of placenta (aRR: 2.12 [2.07 to 2.16]), gestational hypertension (aRR: 1.55 [1.51-1.59]), preeclampsia (aRR: 1.54 [1.51-1.57]), preterm birth (aRR: 1.48 [1.46-1.51]), fetal distress (aRR: 1.39 [1.37-1.42]), and FGR (aRR: 1.36 [1.30-1.42]), but no significant difference in eclampsia (aRR: 0.91 [0.80-1.04]) was found. The absolute risk of each outcome with increasing maternal age in both the IVF and non-IVF group presented two patterns: an upward curve showing in placenta previa, placenta accreta, abnormal morphology of placenta, and gestational hypertension; and a J-shape curve showing in placental abruption, preeclampsia, eclampsia, preterm birth, fetal distress, and FGR.

CONCLUSION

IVF is an independent risk factor for placental abnormalities and placental-related complications, and the risk is associated with maternal age. Further research is needed to evaluate the long-term placenta-related chronic diseases of IVF patients and their offspring.

Birthweight associations with parental obesity: retrospective analysis of 1,778 singleton term births following assisted reproductive treatment

Objective

To determine the association of combined parental preconception overweight and obesity on infant birthweight.

Design

Retrospective study of fresh in vitro fertilization or intracytoplasmic sperm injection cycles (2009–2017).

Setting

Repromed, South Australia, assisted reproductive technology clinic.

Patients

Couples undergoing in vitro fertilization/intracytoplasmic sperm injection insemination with their own gametes and transfer of a fresh single blastocyst (N = 1,778).

Intervention(s)

None.

Main Outcome Measures

Parental body mass index (BMI) was recorded prior to cycle initiation. Infant birthweight was recorded at delivery. The impact of parental obesity and their interaction on first singleton term (≥37 weeks’ gestation) birthweight was assessed using linear regressions assessing nonlinearity and a pairwise linear interactions.

Results

In the base model where parental BMI is assumed linear, there was strong evidence for higher birthweight with increasing maternal BMI (11.2 g per maternal kg/m²; 95% confidence interval, 7.2, 15.1) but not paternal BMI. The inclusion of a pairwise linear interaction indicated that paternal BMI attenuates the positive association between maternal BMI and infant birthweight (interaction −0.88; 95% confidence interval, −1.49, −0.27). The inclusion of nonlinear maternal BMI terms did not change the conclusions.

Conclusions

Increases in the mean infant birthweight associated with maternal obesity are attenuated when the father is obese. While maternal BMI contributed more to the mean infant birthweight than paternal BMI, a couple-centered approach to preconception health advice is recommended, given the documented relationships between parental obesity and childhood weight beyond infancy. Further studies in both assisted reproductive technology and general population cohorts assessing the parental BMI interaction on infant birthweight are warranted.

Prevalence of Congenital Heart Defects in Pregnancies Conceived by Assisted Reproductive Technology: A Cohort Study

BACKGROUND AND AIM OF THE STUDY

Pregnancies obtained by assisted reproductive technology (ART) are associated with an increased risk of complications and congenital anomalies, particularly congenital heart defects (CHDs). Therefore, our aim is to evaluate, retrospectively, the prevalence of CHD in ART pregnancies in our two centers and analyze their characteristics and outcomes.

METHODS

Observational study including fetuses conceived by ART referred between June 2011 and September 2020 and undergoing a fetal cardiac ultrasound scan. Cases with genetic, chromosomal abnormalities or extracardiac malformations were excluded. Population included 1511 pregnancies, which consisted of 269 twins and 1242 singletons, 547 IVF (in vitro fertilization), 773 ICSI (intracytoplasmic sperm injection) and 191 oocyte donations (OD).

RESULTS

CHDs were found in 29 fetuses, with an overall prevalence of 1.92% (29/1511), 1.85% (23/1242) in singletons and 2.23% in twins (6/269). Thirteen were IVF, eight ICSI and eight OD cases, with a greater risk of CHD after IVF and OD (IVF: 13/29 (44.8%)-one twin; ICSI: 8/29 (27.6%)-three twins); 22 had major and 7 minor defects. Two pregnancies with a hypoplastic left heart were terminated; the majority of live-born cases needed surgery. Three babies died (two post-surgery, one had a late death).

CONCLUSIONS

Our data show an increased prevalence of CHD after ART with a heterogeneous spectrum of diagnoses, mainly major defects.

Prevalence of Congenital Heart Defects in Pregnancies Conceived by Assisted Reproductive Technology: A Cohort Study

BACKGROUND AND AIM OF THE STUDY

Pregnancies obtained by assisted reproductive technology (ART) are associated with an increased risk of complications and congenital anomalies, particularly congenital heart defects (CHDs). Therefore, our aim is to evaluate, retrospectively, the prevalence of CHD in ART pregnancies in our two centers and analyze their characteristics and outcomes.

METHODS

Observational study including fetuses conceived by ART referred between June 2011 and September 2020 and undergoing a fetal cardiac ultrasound scan. Cases with genetic, chromosomal abnormalities or extracardiac malformations were excluded. Population included 1511 pregnancies, which consisted of 269 twins and 1242 singletons, 547 IVF (in vitro fertilization), 773 ICSI (intracytoplasmic sperm injection) and 191 oocyte donations (OD).

RESULTS

CHDs were found in 29 fetuses, with an overall prevalence of 1.92% (29/1511), 1.85% (23/1242) in singletons and 2.23% in twins (6/269). Thirteen were IVF, eight ICSI and eight OD cases, with a greater risk of CHD after IVF and OD (IVF: 13/29 (44.8%)-one twin; ICSI: 8/29 (27.6%)-three twins); 22 had major and 7 minor defects. Two pregnancies with a hypoplastic left heart were terminated; the majority of live-born cases needed surgery. Three babies died (two post-surgery, one had a late death).

CONCLUSIONS

Our data show an increased prevalence of CHD after ART with a heterogeneous spectrum of diagnoses, mainly major defects.

Obstetric and neonatal outcomes of pregnancies resulting from preimplantation genetic testing: a systematic review and meta-analysis

BACKGROUND

Preimplantation genetic testing (PGT) includes methods that allow embryos to be tested for severe inherited diseases or chromosomal abnormalities. In addition to IVF/ICSI and repeated freezing and thawing of the embryos, PGT requires a biopsy to obtain embryonic genetic material for analysis. However, the potential effects of PGT on obstetric and neonatal outcomes are currently uncertain.

OBJECTIVE AND RATIONALE

This study aimed to investigate whether pregnancies conceived after PGT were associated with a higher risk of adverse obstetric and neonatal outcomes compared with spontaneously conceived (SC) pregnancies or pregnancies conceived after IVF/ICSI.

SEARCH METHODS

PubMed, EMBASE, MEDLINE, Web of Science and The Cochrane Library entries from January 1990 to January 2021 were searched. The primary outcomes in this study were low birth weight (LBW) and congenital malformations (CMs), and the secondary outcomes included gestational age, preterm delivery (PTD), very preterm delivery (VPTD), birth weight (BW), very low birth weight (VLBW), neonatal intensive care unit (NICU) admission, hypertensive disorders of pregnancy (HDP), gestational diabetes, placenta previa and preterm premature rupture of membranes (PROM). We further pooled the results of PGT singleton pregnancies. Subgroup analyses included preimplantation genetic diagnosis (PGD), preimplantation genetic screening (PGS), cleavage-stage biopsy combined with fresh embryo transfer (CB-ET) and blastocyst biopsy combined with frozen-thawed embryo transfer (BB-FET).

OUTCOMES

This meta-analysis included 15 studies involving 3682 babies born from PGT pregnancies, 127 719 babies born from IVF/ICSI pregnancies and 915 222 babies born from SC pregnancies. The relative risk (RR) of LBW was higher in PGT pregnancies compared with SC pregnancies (RR = 3.95, 95% confidence interval [CI]: 2.32-6.72), but the risk of CMs was not different between the two groups. The pooled results for the risks of LBW and CMs were similar in PGT and IVF/ICSI pregnancies. The risks of PTD (RR = 3.12, 95% CI: 2.67-3.64) and HDP (RR = 3.12, 95% CI: 2.18-4.47) were significantly higher in PGT pregnancies compared with SC pregnancies. Lower gestational age (mean difference [MD] = -0.76 weeks, 95% CI -1.17 to -0.34) and BW (MD = -163.80 g, 95% CI: -299.35 to -28.24) were also noted for PGT pregnancies compared with SC pregnancies. Nevertheless, compared with IVF/ICSI pregnancies, the risks of VPTD and VLBW in PGT pregnancies were significantly decreased by 41% and 30%, respectively, although the risk of HDP was still significantly increased by 50% in PGT pregnancies compared with IVF/ICSI pregnancies. The combined results of obstetric and neonatal outcomes of PGT and IVF/ICSI singleton pregnancies were consistent with the overall results. Further subgroup analyses indicated that both PGD and PGS pregnancies were associated with a higher risk of PTD and a lower gestational age compared with SC pregnancies.

WIDER IMPLICATIONS

This meta-analysis showed that PGT pregnancies may be associated with increased risks of LBW, PTD and HDP compared with SC pregnancies. The overall obstetric and neonatal outcomes of PGT pregnancies are favourable compared with those of IVF/ICSI pregnancies, although PGT pregnancies were associated with a higher risk of HDP. However, because the number of studies that could be included was limited, more randomised controlled trials and prospective cohort studies are needed to confirm these conclusions.

Asthma and allergies in offspring conceived by ART: a systematic review and meta-analysis

BACKGROUND

Currently, 1 in 25 children born in Australia are conceived through ARTs such as IVF and ICSI. Worldwide over 8 million children have been born after ART. There is evidence that these children are at an increased risk of congenital malformations, preterm birth, low birth weight and neonatal morbidity. However, studies on long-term health outcomes of offspring conceived after ART are lacking. Atopic disorders, such as asthma, atopic dermatitis and various allergies are increasingly common within society, and concerns have been raised that ART increases the risk of atopy amongst offspring.

OBJECTIVE AND RATIONALE

The aim of this study was to systematically summarise and quantify the risk of atopic disorders in offspring conceived with ART compared to those conceived without ART.

SEARCH METHODS

A systematic review was conducted according to the PRISMA guidelines. Several systematic searches were performed in the following international databases: Medline, Embase, Cinahl, PsychINFO, AMED, Global Health and ISI Web of Science. Search terms utilised were all terms pertaining to ART, IVF, ICSI, asthma, atopic dermatitis and allergies. The search period was 1978-2021. Included observational studies stated a primary outcome of asthma or allergies in offspring conceived after ART, with a comparison group conceived without ART. Individual studies were scored on quality and risk of bias, using the Newcastle-Ottawa scale (NOS).

OUTCOMES

There were 26 studies which met the inclusion criteria; of these, 24 studies investigated asthma in offspring conceived after ART. While 10 studies, including the two largest population-based studies, reported a significantly increased risk of asthma in offspring conceived after ART (adjusted odds ratio (aOR) range: 1.20-2.38), 14 smaller cohort studies found no difference (aOR range 0.70-1.27). In the meta-analysis of the 14 highest-quality studies (NOS ≥ 7), a modest yet significantly increased risk of asthma was demonstrated in offspring conceived after ART [risk ratio (RR) 1.28 (1.08-1.51)]. Although heterogeneity in these 14 studies was high (I2 = 85%), the removal of outliers and high weight studies significantly reduced heterogeneity (I2 = 0% and I2 = 34% respectively) while still demonstrating a significantly increased risk [RR 1.19 (1.10-1.28) and RR 1.31 (1.03-1.65), respectively]. The increased asthma risk was also observed in most subgroup and sensitivity analyses. The allergy rates were not increased in offspring conceived after ART in 9 of 12 studies (aOR range 0.60-1.30). In summary, the findings of this systematic review and meta-analysis suggest a trend towards a significantly increased risk of asthma, but not allergies, in offspring conceived after ART. There was no evidence of publication bias in the asthma studies and minimal evidence of publication bias in the allergy studies (both P > 0.05).

WIDER IMPLICATIONS

Asthma brings considerable burden to the quality of life of individuals and to society. Hence, it is of great importance to untangle potential causal pathways. Although ART use is common, knowledge about its long-term health effects is required to provide evidence-based advice to couples considering ART, and to be vigilant for any potential adverse health effects on offspring conceived after ART.

Impact of endometriosis on obstetric outcome after natural conception: a multicenter Italian study

Purpose

To evaluate obstetric outcome in women with endometriosis who conceive naturally and receive standard obstetric care in Italy.

Methods

Cases were consecutive women with endometriosis managed in eleven Italian referral centers. Controls were women in whom endometriosis was excluded. All women filled in a questionnaire addressing previous natural pregnancies. Marginal logistic regression models were fitted to evaluate the impact of endometriosis on obstetric outcome. A post hoc analysis was performed within the endometriosis group comparing women with severe adenomyosis versus women with absent or mild adenomyosis.

Results

Three hundred and fifty-five pregnancies in endometriosis group and 741 pregnancies in control group were included. Women with endometriosis had a higher risk of preterm delivery < 34 weeks (6.4% vs 2.8%, OR 2.42, 95% CI 1.22–4.82), preterm delivery < 37 weeks (17.8% vs 9.7%, OR 1.98, 95% CI 1.23–3.19), and neonatal admission to Intensive Care Unit (14.1% vs 7.0%, OR 2.04, 95% CI 1.23–3.36). At post hoc analysis, women with endometriosis and severe adenomyosis had an increased risk of placenta previa (23.1% vs 1.8%, OR 16.68, 95% CI 3.49–79.71), cesarean delivery (84.6% vs 38.9%, OR 8.03, 95% CI 1.69–38.25) and preterm delivery < 34 weeks (23.1% vs 5.7%, OR 5.52, 95% CI 1.38–22.09).

Conclusion

Women with endometriosis who conceive naturally have increased risk of preterm delivery and neonatal admission to intensive care unit. When severe adenomyosis is coexistent with endometriosis, women may be at increased risk of placenta previa and cesarean delivery.

Trial registration

Clinical trial registration number: NCT03354793.

Secular changes in human reproduction and assisted reproductive technologies

Since the middle to late 20th century the majority of children born in the developing world have been likely to enter into post-reproductive age. Currently, child mortality is at its lowest level in human history. While more children are living to post reproductive age, approximately 15% of couples are experiencing infecundity. This is either a result of one or both members of the couple being infecund, or, despite both being fecund, the interaction between them prevents fertility for some reason. Assisted reproductive technologies have provided many infertile couples an opportunity to have children. Assisted reproductive technologies operate by intervening and manipulating gametic and intrauterine natural selection. This paper discusses the possible influence of assisted reproductive technologies on child development. This paper outlines some of the reported changes in children resulting from assisted reproductive technologies. Although, few people are either aware or care about possible long term consequences of relaxed natural selection contributed by medical intervention (i.e. assisted reproductive technologies) we have little understanding to what extent such medical interference may affect long term fitness in humans.

Analyses of child cardiometabolic phenotype following assisted reproductive technologies using a pragmatic trial emulation approach

Assisted reproductive technologies (ART) are increasingly used, however little is known about the long-term health of ART-conceived offspring. Weak selection of comparison groups and poorly characterized mechanisms impede current understanding. In a prospective cohort (Growing Up in Singapore Towards healthy Outcomes; GUSTO; Clinical Trials ID: NCT01174875) including 83 ART-conceived and 1095 spontaneously-conceived singletons, we estimate effects of ART on anthropometry, blood pressure, serum metabolic biomarkers, and cord tissue DNA methylation by emulating a pragmatic trial supported by machine learning-based estimators. We find ART-conceived children to be shorter (-0.5 SD [95% CI: -0.7, -0.2]), lighter (-0.6 SD [-0.9, -0.3]) and have lower skinfold thicknesses (e.g. -14% [-24%, -3%] suprailiac), and blood pressure (-3 mmHg [-6, -0.5] systolic) at 6-6.5 years, with no strong differences in metabolic biomarkers. Differences are not explained by parental anthropometry or comorbidities, polygenic risk score, breastfeeding, or illnesses. Our simulations demonstrate ART is strongly associated with lower NECAB3 DNA methylation, with negative control analyses suggesting these estimates are unbiased. However, methylation changes do not appear to mediate observed differences in child phenotype.

Do frozen embryo transfers modify the epigenetic control of imprinted genes and transposable elements in newborns compared with fresh embryo transfers and natural conceptions?

OBJECTIVE

To determine whether the epigenetic control of imprinted genes (IGs) and transposable elements (TEs) differs at birth between fresh or frozen embryo transfers and natural conceptions.

DESIGN

Prospective study.

SETTING

University hospital.

PATIENT(S)

A total of 202 singleton births were divided into three groups: 84 natural pregnancies (controls), 66 in vitro fertilization/intracytoplasmic sperm injection with fresh embryo transfers, and 52 vitro fertilization/intracytoplasmic sperm injection with frozen embryo transfers.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Pyrosequencing was used to assess the DNA methylation profiles of three IGs (H19/IGF2:IG-DMR [two sequences], KCNQ1OT1:TSS-DMR, and SNURF:TSS-DMR) and two TEs (LINE-1 and HERV-FRD) in cord blood and placenta. The quantitative reverse transcriptase polymerase chain reaction was used to study the transcription of three IGs (H19, KCNQ1, and SNRPN) and two TEs (LINE-1 and ORF2).

RESULT(S)

After adjustment, the placental DNA methylation levels of H19/IGF2 were lower in the fresh embryo transfer group than in the control (H19/IGF2-seq1) and frozen embryo transfer (H19/IGF2-seq2) groups. The DNA methylation rate for LINE-1 was lower in placentas from the fresh embryo transfer group than in placentas from the control and frozen embryo transfer groups and for HERV-FRD compared with controls. In cord blood, DNA methylation levels were not significantly associated with the mode of conception. The relative expression of LINE-1 and ORF2 was decreased in both cord blood and placental tissues from fresh embryo transfer conceptions compared with natural conceptions and frozen embryo transfer conceptions.

CONCLUSION(S)

Compared with natural conceptions and frozen embryo transfers, fresh embryo transfers were associated with methylation and/or transcription changes in some TEs and IGs, mostly in placental samples, which could indicate altered placental epigenetic regulation resulting from ovarian stimulation protocols.

Maternal haemodynamic profile in pregnancy after assisted reproductive technology: A pilot study

Singleton pregnancies obtained by assisted reproductive technology (ART) are at increased risk of adverse pregnancy outcome. Aim of this pilot study was to compare maternal hemodynamic profile in ART and spontaneous singleton pregnancies. Patients were enrollered during a third trimester routine obstetric examination. Maternal haemodynamic assessment was carried out by a single trained operator using an UltraSonic Cardiac Output Monitor in standardized conditions. Our pilot data suggests that women conceived after ART may have significantly lower Cardiac Output and significantly higher Systemic Vascular Resistance when compared to those conceiving spontaneously. These differences, if confirmed in larger studies, might explain the increased prevalence of adverse outcome, especially hypertensive disorders of pregnancy, in singleton ART pregnancies.

Absolute Risk of Adverse Obstetric Outcomes Among Twin Pregnancies After In Vitro Fertilization by Maternal Age

IMPORTANCE

Twin pregnancy is a common occurrence in pregnancies conceived with in vitro fertilization (IVF), but the absolute risk of adverse obstetric outcomes stratified by IVF, twin or singleton pregnancy, and maternal age are unknown.

OBJECTIVE

To estimate the absolute risk of adverse obstetric outcomes at each maternal age among twin pregnancies conceived with IVF.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study included pregnant women with infants born from January 1, 2013, to December 31, 2018, based on the Hospital Quality Monitoring System in China. Data were analyzed from September 1, 2020, to June 30, 2021.

EXPOSURES

Twin pregnancy with IVF (IVF-T), singleton pregnancy with IVF (IVF-S), twin pregnancy with non-IVF (nIVF-T), and singleton pregnancy with non-IVF (nIVF-S).

MAIN OUTCOMES AND MEASURES

Sixteen obstetric outcomes, including 10 maternal complications (gestational hypertension, eclampsia and preeclampsia, gestational diabetes, placenta previa, placental abruption, placenta accreta, preterm birth, dystocia, cesarean delivery, and postpartum hemorrhage) and 6 neonatal complications (fetal growth restriction, low birth weight, very low birth weight, macrosomia, malformation, and stillbirth).

RESULTS

Among 16 879 728 pregnant women aged 20 to 49 years (mean [SD] age, 29.2 [4.7] years), the twin-pregnancy rates were 32.1% in the IVF group and 1.5% in the non-IVF group (relative risk, 20.8; 95% CI, 20.6-20.9). The most common adverse obstetric outcomes after pregnancy conceived with IVF were cesarean delivery (88.8%), low birth weight (43.8%), preterm birth (39.6%), gestational diabetes (20.5%), gestational hypertension and preeclampsia and eclampsia (17.5%), dystocia (16.8%), and postpartum hemorrhage (11.9%). The absolute risk of most adverse obstetric outcomes in each subgroup presented in 2 dominant patterns: Pattern A indicated the absolute risk ranging from IVF-T to nIVF-T to IVF-S to nIVF-S, and pattern B indicated the absolute risk ranging from IVF-T to IVF-S to nIVF-T to nIVF-S. Both patterns showed an elevated obstetric risk with increasing maternal age in each subgroup.

CONCLUSIONS AND RELEVANCE

In this cohort study, twin pregnancy, IVF, and advanced maternal age were independently associated with adverse obstetric outcomes. Given these findings, promotion of the elective single embryo transfer strategy is needed to reduce multiple pregnancies following IVF technologies. Unnecessary cesarean delivery shouldh be avoided in all pregnant women.

Does amniotic fluid sludge result in preterm labor in pregnancies after assisted reproduction technology? A nested Case - Control study

OBJECTIVE

to investigate the relationship between the Amniotic fluid Sludge exposure during pregnancy and the Preterm Labor (PTL) in pregnant women who had undergone Assisted Reproductive Technology procedures (ART) in Royan institute.

MATERIALS AND METHODS

It was a nested case-control study that was conducted on 110 eligible pregnant women who had undergone IVF procedure in Royan institute, Tehran, Iran. The final sample size was 63 subjects with Amniotic fluid Sludge and 67 subjects with normal Amniotic fluid. Delivery before 37 of gestation was considered as PTL.The study was approved by the ethics committee of the Royan institute and the written consent form was filled by participants. Data was entered to the SPSS (version 21, SPSS, Inc.). The baseline characteristics of the participants were described as absolute (n) and relative (%) frequencies for the covariates. Man Whitney and T-Test were used to compare the mean of covariates and the P-value lower than 0.05 was considered significant. The prevalence of the PTL was compared between two groups.

RESULTS

The mean Gestational Age at delivery in case and control group were 36.46 ± 3.45 and 38.03 ± 1.61, respectively which was significant (p = .01). The prevalence of PTL in case and control group were 23.8% and 10.4% respectively which was significant (p = .04). The percentage of cases with cervical length less than 30 (mm) in case and control group were 28.6% and 10.4%, respectively (p = .008) and the percentage of cerclage in case and control group were 33.3% and 7.5% respectively, (p = .00) which were significant statistically.

CONCLUSION

The amniotic fluid sludge has a direct effect on the cervical length of pregnancies after ART. In such cases, PTB will be probable in the presence of sludge in spite of preventive treatments such as cerclage.