Assisted reproductive technology and perinatal outcomes: conventional versus discordant-sibling design

Comparative Proteomic and Phospho-proteomic Analysis of Mouse Placentas Generated via In Vivo and In Vitro Fertilization

Offspring conceived by assisted reproductive technologies (ART) have increased risk of suffering from gestational complications, and placental dysfunction is related with the adverse outcomes. Studies have revealed that abnormal or adaptive changes can occur in ART placentas, but the potential reasons are not fully understood. Hereby, we tried to use proteomics and phospho-proteomics to find the underlying mechanisms responsible for the changes of ART placentas. Liquid chromatography-tandem mass spectrometry was utilized to perform proteome and phospho-proteome detection on mouse placentas. The differential expressed proteins (DEPs) or phospho-proteins (DEPPs) were analyzed based on subcellular localization, functional classification, and enrichment. Western blot was used to verify the DEPs (Afadin, ZO-1, Ace2, Agt, Slc7a5, and Slc38a10) and measure mTOR signaling activities (mTOR, Rps6, and 4Ebp1). The data showed that 161 DEPs and 304 DEPPs were found in proteome and phospho-proteome, respectively. Multiple biological processes were enriched based on those DEPs and DEPPs, and renin-angiotensin system, cell junction, and PI3K-Akt pathway were investigated. By protein expression identification, two key proteins associated with renin-angiotensin system (Ace2 and Agt) were down-regulated, and the levels of Afadin and ZO-1 (related with cell junction) as well as Slc38a10 were increased in IVF placentas. In addition, mTOR downstream activities were increased as shown by p-Rps6 and p-4Ebp1 in IVF placentas. In conclusion, IVF leads to the changes of cell junction, renin-angiotensin system, amino acid transport, and increased mTOR signaling in mouse placentas, which may be associated with the altered structure and function of IVF placentas.

Assisted reproductive technology, risk of gestational diabetes, and perinatal outcomes in singleton pregnancies

AIMS

To evaluate the impact of assisted reproductive technology (ART) on the risk of gestational diabetes mellitus (GDM) in single pregnancies.

MATERIALS AND METHODS

We retrospectively collected clinical and anthropometric data of 219ART- and 256 age- and body mass index (BMI)-matched women with spontaneous conception screened for GDM. The primary outcome was to evaluate GDM prevalence in ART women.

RESULTS

There were no differences in age, BMI, and family history of diabetes in the two groups of women. ART-women were more frequently primiparous, whereas the prevalence of previous GDM was higher in SC-women. The prevalence of GDM in the whole cohort was 36.1% and was higher in ART-women (52.3% vs. 23.4%; p < 0.0001). In the whole cohort, on multivariate analysis, family history of diabetes (OR 1.67; 95% CI: 1.03-2.69), previous GDM (OR 7.05; 95% CI: 2.92-17.04), pre-pregnancy obesity (OR 2.72; 95% CI 1.21-6.13), and ART (OR 4.14; 95% CI 2.65-6.48) were independent risk factors for GDM. Among ART-women, age over 40 years was associated with GDM. Preterm delivery was more common in ART-women; gestational week at delivery, birth weight, ponderal index, and Apgar score were lower in ART-women than in SC-women, both in the whole cohort and in GDM women.

CONCLUSIONS

Among women undergoing ART treatment, at least one in two develops GDM. ART appears to be an independent risk factor for GDM in single pregnancies, particularly above the age of 40. ART treatment seems to be associated with an increased rate of preterm delivery and lower neonatal birth weight and Apgar score, especially in GDM women.

CLINICAL TRIAL REGISTRATION

The study was not registered as it is an observational retrospective evaluation.

Effects of assisted reproductive technology on gene expression in heart and spleen tissues of adult offspring mouse

OBJECTIVES

Assisted reproductive technology (ART) is an important part of reproductive medicine, whose possible effects on offspring's health have drawn widespread attention in recent years. However, relevant studies are limited to postnatal short-term follow-up and lack of diverse sample sources analysis other than blood.

METHODS

In this study, a mouse model was used to explore the effects of ART on fetal development and gene expression in the organs of offspring in the adulthood using next-generation sequencing. The sequencing results were then analyzed.

RESULTS

The results showed that it caused abnormal expression in 1060 genes and 179 genes in the heart and spleen, respectively. Differentially expressed genes (DEGs) in the heart are mainly enriched in RNA synthesis and processing, and the cardiovascular system development also shows enrichment. STRING analysis identified Ccl2, Ptgs2, Rock1, Mapk14, Agt, and Wnt5a as the core interacting factors. DEGs in the spleen are significantly enriched in anti-infection and immune responses, which include the core factors Fos, Jun and Il1r2. Further exploration revealed the abnormal expression of 42 and 5 epigenetic modifiers in the heart and spleen, respectively. The expression of the imprinted genes Dhcr7, Igf2, Mest and Smoc1 decreased in the hearts of ART offspring, and the DNA methylation levels of Igf2- and Mest-imprinting control regions (ICRs) increased abnormally.

CONCLUSION

In the mouse model, ART can interfere with the gene expression pattern in the heart and spleen of the adult offspring and that these changes are related to the aberrant expression of epigenetic regulators.

Assisted reproductive technology: Short- and long-term outcomes

Assisted reproductive technology (ART) includes fertility treatment in which either eggs or embryos are handled outside a female's body to promote successful pregnancies and healthy offspring. Current ART procedures encompass in vitro fertilization with or without intracytoplasmic sperm injection. The most common complication of ART is related to the consequences of multiple pregnancy, which can be prevented or minimized by reducing the number of embryos transferred to the uterus, commonly single embryo transfer. ART has been shown to be variably associated with adverse short- and long-term perinatal outcomes, including cerebral palsy, autism, neurodevelopmental imprinting disorders, and cancer. However, there is uncertainty as to whether reported problems are related to the ART procedure itself, to factors related to infertility, to other medical and environmental factors, or a combination thereof. From a pathophysiological perspective, whether ART alters epigenetic mechanisms of gene expression, leading to later developmental, medical, and behavioral disorders, is an area of active investigation. With the meticulously conducted short- and long-term outcome studies completed so far, overall, and after controlling for multiple gestations and preterm delivery, the results suggest that ART is a safe procedure, offering hope to many parent(s) wishing for a healthy child. This paper highlights ART methods and the risk factors and confounders in the interpretation of short- and long-term outcome data, providing the reader with a means to evaluate findings and conclusions of outcome studies. WHAT THIS PAPER ADDS: Assisted reproductive technology (ART) is a relatively safe procedure. Single embryo implantation optimizes outcome. Informed consent, including the risks and benefits of ART, should be required. Ongoing longitudinal studies are necessary to fully understand ART outcomes.

Assisted Reproductive Technology or Infertility: What underlies adverse outcomes? Lessons from the Massachusetts Outcome Study of Assisted Reproductive Technology

Numerous studies have demonstrated that assisted reproductive technology (ART: defined here as including only in vitro fertilization and related technologies) is associated with increased adverse pregnancy, neonatal, and childhood developmental outcomes, even in singletons. The comparison group for many had often been a fertile population that conceived without assistance. The Massachusetts Outcome Study of Assisted Reproductive Technology (MOSART) was initiated to define a subfertile population with which to compare ART outcomes. Over more than 10 years, we have used the MOSART database to study pregnancy abnormalities and delivery complications but also to evaluate ongoing health of women, infants, and children. This article will review studies from MOSART in the context of how they compare with those of other investigations. We will present MOSART studies that identified the influence of ART and subfertility/infertility on adverse pregnancy (pregnancy hypertensive disorder, gestational diabetes, placental abnormality) and delivery (preterm birth, low birthweight) outcomes as well as on maternal and child hospitalizations. We will provide evidence that although subfertility/infertility increases the risk of adverse outcomes, there is additional risk associated with the use of ART. Studies exploring the contribution of placental abnormalities as one factor adding to this increased ART-associated risk will be described.

Association of Assisted Reproductive Technology With Offspring Growth and Adiposity From Infancy to Early Adulthood

Importance

People conceived using assisted reproductive technology (ART) make up an increasing proportion of the world's population.

Objective

To investigate the association of ART conception with offspring growth and adiposity from infancy to early adulthood in a large multicohort study.

Design, Setting, and Participants

This cohort study used a prespecified coordinated analysis across 26 European, Asia-Pacific, and North American population-based cohort studies that included people born between 1984 and 2018, with mean ages at assessment of growth and adiposity outcomes from 0.6 months to 27.4 years. Data were analyzed between November 2019 and February 2022.

Exposures

Conception by ART (mostly in vitro fertilization, intracytoplasmic sperm injection, and embryo transfer) vs natural conception (NC; without any medically assisted reproduction).

Main Outcomes and Measures

The main outcomes were length / height, weight, and body mass index (BMI; calculated as weight in kilograms divided by height in meters squared). Each cohort was analyzed separately with adjustment for maternal BMI, age, smoking, education, parity, and ethnicity and offspring sex and age. Results were combined in random effects meta-analysis for 13 age groups.

Results

Up to 158 066 offspring (4329 conceived by ART) were included in each age-group meta-analysis, with between 47.6% to 60.6% females in each cohort. Compared with offspring who were NC, offspring conceived via ART were shorter, lighter, and thinner from infancy to early adolescence, with differences largest at the youngest ages and attenuating with older child age. For example, adjusted mean differences in offspring weight were -0.27 (95% CI, -0.39 to -0.16) SD units at age younger than 3 months, -0.16 (95% CI, -0.22 to -0.09) SD units at age 17 to 23 months, -0.07 (95% CI, -0.10 to -0.04) SD units at age 6 to 9 years, and -0.02 (95% CI, -0.15 to 0.12) SD units at age 14 to 17 years. Smaller offspring size was limited to individuals conceived by fresh but not frozen embryo transfer compared with those who were NC (eg, difference in weight at age 4 to 5 years was -0.14 [95% CI, -0.20 to -0.07] SD units for fresh embryo transfer vs NC and 0.00 [95% CI, -0.15 to 0.15] SD units for frozen embryo transfer vs NC). More marked differences were seen for body fat measurements, and there was imprecise evidence that offspring conceived by ART developed greater adiposity by early adulthood (eg, ART vs NC difference in fat mass index at age older than 17 years: 0.23 [95% CI, -0.04 to 0.50] SD units).

Conclusions and Relevance

These findings suggest that people conceiving or conceived by ART can be reassured that differences in early growth and adiposity are small and no longer evident by late adolescence.

Comparison of perinatal outcomes after frozen or fresh embryo transfer: separate analyses of singleton, twin, and sibling live births from a linked national in vitro fertilization registry

OBJECTIVE

To determine whether perinatal outcomes following frozen vs. fresh embryo transfer (ET) differ within singletons, within sets of twins, and between siblings.

DESIGN

Population-based retrospective cohort study.

SETTING

Academic Medical School PATIENT(S): 200,075 live births in 151,561 women who underwent in vitro fertilization with frozen or fresh ET between 1992 and 2017.

MAIN OUTCOME MEASURE(S)

Gestational age at birth, birthweight, congenital anomaly, and healthy baby (≥37 weeks of gestation, birthweight 2,500-4,000 g, no congenital malformations).

RESULT(S)

There were 200,075 live births in 151,561 women including 132,679 singletons, 33,698 sets of twins, and 5,723 pairs of singleton siblings. In singletons, frozen ET was associated with a lower risk of very preterm birth (adjusted relative risk [aRR], 0.83; 95% confidence interval [CI], 0.73, 0.94), preterm birth (aRR, 0.93; 95% CI, 0.88, 0.97), low birthweight (<2,500 g) (aRR, 0.72; 95% CI, 0.68, 0.77), small for gestational age (aRR, 0.66; 95% CI, 0.62, 0.70) and congenital anomaly (aRR, 0.85; 95% CI, 0.78, 0.94), but higher risk of high birthweight (>4,000 g) (aRR, 1.64; 95% CI, 1.58, 1.72) and large for gestational age (aRR, 1.62; 95% CI, 1.55, 1.70) in comparison with fresh ET. In twins, frozen ET was associated with lower risk of very preterm birth (aRR, 0.84; 95% CI, 0.73, 0.97), and low birthweight (aRR, 0.72; 95% CI, 0.68, 0.77), but with a higher chance of a healthy baby (aRR, 1.11; 95% CI, 1.06, 1.16) compared to fresh ET. Singletons conceived following frozen ET had a lower risk of low birthweight (aRR, 0.56; 95% CI, 0.44, 0.74) and being small for gestational age (aRR, 0.54; 95% CI, 0.42, 0.68) than a singleton sibling born after a fresh ET. Frozen ET also was associated with higher risk of high birthweight (aRR, 1.85; 95% CI, 1.54, 2.24) and being large for gestational age (aRR, 1.81; 95% CI, 1.50, 2.20), and also were less likely to be preterm (aRR, 0.81; 95% CI, 0.67, 0.99).

CONCLUSION(S)

Our key finding is that singletons born following a frozen ET are less likely to be small for gestational age than a singleton sibling born following fresh ET but are more likely to be large for gestational age.

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.

Obstetric outcomes in pregnancies resulting from in vitro fertilization are not different in fertile, sterilized women compared to infertile women: A Society for Assisted Reproductive Technology database analysis

OBJECTIVE

To compare obstetric and neonatal outcomes resulting from assisted reproductive technology in couples with a history of female sterilization to couples with other infertility diagnoses.

DESIGN

Retrospective cohort study.

SETTING

Not applicable.

PATIENT(S)

Fresh, nondonor cycles excluding gestational surrogacy from 2004 to 2013 in the United States.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Preterm birth rates and low birth weight rates from in vitro fertilization (IVF) pregnancies in couples with infertility and in couples with prior tubal ligation as their sole indication for IVF.

RESULT(S)

The mean ages of fertile women (N = 8,478) and infertile women (N = 371,488) were 35.3 and 34.6 years, respectively. Of the singletons born to parous women (N = 26,463), the incidence of preterm birth was not significantly different in fertile, sterilized couples compared to infertile couples (13.7% vs. 12.0%). The incidence of low birth weight among term singletons was also not significantly different between fertile couples compared to infertile couples (3.5% vs. 3.2%).

CONCLUSION(S)

Fertile couples have similar preterm birth and low birth weight rates after IVF compared to infertile couples. This suggests that differences in perinatal outcomes may be due to assisted reproductive technology procedures rather than infertility itself.

Long-Term Disturbed Expression and DNA Methylation of SCAP/SREBP Signaling in the Mouse Lung From Assisted Reproductive Technologies

Assisted reproductive technology (ART) has been linked to cholesterol metabolic and respiratory disorders later in life, but the mechanisms by which biosynthetic signaling remain unclear. Lung inflammatory diseases are tightly linked with the sterol regulatory element-binding protein (SREBP) and SREBP cleavage-activating protein (SCAP), but this has not been shown in an ART offspring. Here, mouse models from a young to old age were established including in vitro fertilization (IVF), intracytoplasmic injection (ICSI), and in vivo fertilized groups. In our results, significantly higher plasma levels of CRP, IgM, and IgG were identified in the aged ICSI mice. Additionally, pulmonary inflammation was found in four aged ART mice. At three weeks, ART mice showed significantly downregulated levels of Scap, Srebp-1a, Srebp-1c, and Srebf2 mRNA in the lung. At the same time, significant differences in the DNA methylation rates of Scap-Srebfs and protein expression of nuclear forms of SREBPs (nSREBPs) were detected in the ART groups. Only abnormalities in the expression levels of Srebp-1a and Srebp-1c mRNA and nSREBP1 protein were found in the ART groups at 10 weeks. However, at 1.5 years old, aberrant expression levels and DNA methylation of SCAP, SREBP1, and SREBP2, and their associated target genes, were observed in the lung of the ART groups. Our results indicate that ART increases long-term alterations in SCAP/SREBP expression that may be associated with their aberrant methylation status in mouse.

Separating parental and treatment contributions to perinatal health after fresh and frozen embryo transfer in assisted reproduction: A cohort study with within-sibship analysis

BACKGROUND

Compared to naturally conceived children, adverse perinatal outcomes are more common among children born after assisted reproductive technology with fresh embryo transfer (fresh-ET) or frozen embryo transfer (frozen-ET). However, most previous studies could not adequately control for family confounding factors such as subfertility. We compared birth size and duration of pregnancy among infants born after fresh-ET or frozen-ET versus natural conception, using a within-sibship design to account for confounding by maternal factors.

METHODS AND FINDINGS

This registry-based cohort study with nationwide data from Denmark (1994-2014), Norway (1988-2015), and Sweden (1988-2015) consisted of 4,510,790 live-born singletons, 4,414,703 from natural conception, 78,095 from fresh-ET, and 17,990 from frozen-ET. We identified 33,056 offspring sibling groups with the same mother, conceived by at least 2 different conception methods. Outcomes were mean birthweight, small and large for gestational age, mean gestational age, preterm (<37 weeks, versus ≥37), and very preterm birth (<32 weeks, versus ≥32). Singletons born after fresh-ET had lower mean birthweight (-51 g, 95% CI -58 to -45, p < 0.001) and increased odds of small for gestational age (odds ratio [OR] 1.20, 95% CI 1.08 to 1.34, p < 0.001), while those born after frozen-ET had higher mean birthweight (82 g, 95% CI 70 to 94, p < 0.001) and increased odds of large for gestational age (OR 1.84, 95% CI 1.56 to 2.17, p < 0.001), compared to naturally conceived siblings. Conventional population analyses gave similar results. Compared to naturally conceived siblings, mean gestational age was lower after fresh-ET (-1.0 days, 95% CI -1.2 to -0.8, p < 0.001), but not after frozen-ET (0.3 days, 95% CI 0.0 to 0.6, p = 0.028). There were increased odds of preterm birth after fresh-ET (OR 1.27, 95% CI 1.17 to 1.37, p < 0.001), and in most models after frozen-ET, versus naturally conceived siblings, with somewhat stronger associations in population analyses. For very preterm birth, population analyses showed increased odds for both fresh-ET (OR 2.03, 95% CI 1.90 to 2.12, p < 0.001) and frozen-ET (OR 1.66, 95% CI 1.42 to 1.94, p < 0.001) compared with natural conception, but results were notably attenuated within siblings (OR 1.18, 95% CI 1.0 to 1.41, p = 0.059, and OR 0.92, 95% CI 0.67 to 1.27, p = 0.6, for fresh-ET and frozen-ET, respectively). Sensitivity analyses in full siblings, in siblings born within 3-year interval, by birth order, and restricting to single embryo transfers and blastocyst transfers were consistent with the main analyses. Main limitations were high proportions of missing data on maternal body mass index and smoking.

CONCLUSIONS

We found that infants conceived by fresh-ET had lower birthweight and increased odds of small for gestational age, and those conceived by frozen-ET had higher birthweight and increased odds of large for gestational age. Conception by either fresh-ET or frozen-ET was associated with increased odds of preterm birth. That these findings were observed within siblings, as well as in conventional multivariable population analyses, reduces the likelihood that they are explained by confounding or selection bias.

TRIAL REGISTRATION

ClinicalTrials.gov ISRCTN11780826.

Growth in children conceived by ART

STUDY QUESTION

Is the growth pattern of children conceived by ART different compared to naturally conceived children.

SUMMARY ANSWER

Both ART and underlying parental subfertility may contribute to differences in early childhood growth between children conceived with and without the use of ART.

WHAT IS KNOWN ALREADY

Children conceived by ART weigh less and are shorter at the time of delivery. The extent to which differences in growth according to mode of conception persist during childhood, and the role of underlying parental subfertility, remains unclear.

STUDY DESIGN, SIZE, DURATION

We conducted a prospective study population-based study. We studied 81 461 children participating in the Norwegian Mother, Father and Child Cohort Study (MoBa) and 544 113 adolescents screened for military conscription.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Conception by ART as registered in the Medical Birth Registry. We compared maternally reported length/height and weight among children in MoBa from mid-pregnancy to age 7 according to mode of conception using mixed-effects linear regression. Differences in self-reported height and weight at 17 years of age at screening for military conscription were assessed with linear regression.

MAIN RESULTS AND THE ROLE OF CHANCE

At birth, children conceived by ART were shorter (boys −0.3 cm; 95% CI, −0.5 to −0.1), girls −0.4 cm; 95% CI, −0.5 to −0.3) and lighter (boys −113 grams; 95% CI, −201 to −25, girls −107 grams; 95% CI, −197 to −17). After birth, children conceived by ART grew more rapidly, achieving both greater height and weight at age 3. Children conceived by ART had a greater height up to age 7, but did not have a greater height or weight by age 17. Naturally conceived children of parents taking longer time to conceive had growth patterns similar to ART children. Children born after frozen embryo transfer had larger ultrasound measures and were longer and heavier the first 2 years than those born after fresh embryo transfer.

LIMITATIONS, REASONS FOR CAUTIONS

Selection bias could have been introduced due to the modest participation rate in the MoBa cohort. Our reliance on self-reported measures of length/height and weight could have introduced measurement error.

WIDER IMPLICATIONS OF THE FINDINGS

: Our findings provide reassurance that offspring conceived by ART are not different in height, weight or BMI from naturally conceived once they reach adolescence.

STUDY FUNDING/COMPETING INTEREST(S)

Research Council of Norway; Medical Research Council; National Institute of Environmental Health Sciences. The authors have no competing interest.

TRIAL REGISTRATION NUMBER

N/A.

DNA methylation differences at birth after conception through ART

STUDY QUESTION

Is there a relation between ART and DNA methylation (DNAm) patterns in cord blood, including any differences between IVF and ICSI?

SUMMARY ANSWER

DNAm at 19 CpGs was associated with conception via ART, with no difference found between IVF and ICSI.

WHAT IS KNOWN ALREADY

Prior studies on either IVF or ICSI show conflicting outcomes, as both widespread effects on DNAm and highly localized associations have been reported. No study on both IVF and ICSI and genome-wide neonatal DNAm has been performed.

STUDY DESIGN, SIZE, DURATION

This was a cross-sectional study comprising 87 infants conceived with IVF or ICSI and 70 conceived following medically unassisted conception. The requirement for inclusion in the study was an understanding of the Swedish language and exclusion was the use of donor gametes.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Participants were from the UppstART study, which was recruited from fertility and reproductive health clinics, and the Born into Life cohort, which is recruited from the larger LifeGene study. We measured DNAm from DNA extracted from cord blood collected at birth using a micro-array (450k array). Group differences in DNAm at individual CpG dinucleotides (CpGs) were determined using robust linear models and post-hoc Tukey’s tests.

MAIN RESULTS AND THE ROLE OF CHANCE

We found no association of ART conception with global methylation levels, imprinted loci and meta-stable epialleles. In contrast, we identify 19 CpGs at which DNAm was associated with being conceived via ART (effect estimates: 0.5–4.9%, P_FDR < 0.05), but no difference was found between IVF and ICSI. The associated CpGs map to genes related to brain function/development or genes connected to the plethora of conditions linked to subfertility, but functional annotation did not point to any likely functional consequences.

LIMITATIONS, REASONS FOR CAUTION

We measured DNAm in cord blood and not at later ages or in other tissues. Given the number of tests performed, our study power is limited and the findings need to be replicated in an independent study.

WIDER IMPLICATIONS OF THE FINDINGS

We find that ART is associated with DNAm differences in cord blood when compared to non-ART samples, but these differences are limited in number and effect size and have unknown functional consequences in adult blood. We did not find indications of differences between IVF and ICSI.

STUDY FUNDING/COMPETING INTEREST(S)

E.W.T. was supported by a VENI grant from the Netherlands Organization for Scientific Research (91617128) and JPI-H2020 Joint Programming Initiative a Healthy Diet for a Healthy Life (JPI HDHL) under proposal number 655 (PREcisE Project) through ZonMw (529051023). Financial support was provided from the European Union’s Seventh Framework Program IDEAL (259679), the Swedish Research Council (K2011-69X-21871-01-6, 2011-3060, 2015-02434 and 2018-02640) and the Strategic Research Program in Epidemiology Young Scholar Awards, Karolinska Institute (to A.N.I.) and through the Swedish Initiative for Research on Microdata in the Social And Medical Sciences (SIMSAM) framework grant no 340-2013-5867, grants provided by the Stockholm County Council (ALF-projects), the Strategic Research Program in Epidemiology at Karolinska Institutet and the Swedish Heart-Lung Foundation and Danderyd University Hospital (Stockholm, Sweden). The funders had no role in study design, data collection, analysis, decision to publish or preparation of the manuscript. The authors declare no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

Pregnancy outcomes of Chinese women undergoing IVF with embryonic cryopreservation as compared to natural conception

Background

To examine differences in the maternal characteristics and pregnancy outcomes of Chinese women with various causes of infertility who underwent in vitro fertilization (IVF) with embryonic cryopreservation treatment.

Methods

Cases were pregnancies after IVF-ET with embryonic cryopreservation; controls were spontaneously conceived pregnancies. Subgroup analysis was carried out according to etiology of infertility. The IVF treatment group was divided into 5 subgroups according to infertility etiology as follows: ovulation disorder, tubal disease, male infertility, endometriosis, and mixed infertility. Data on demographic characteristics, medical history, laboratory tests, and delivery were reviewed. Logistic regression analysis was performed for pregnancy and perinatal complications and neonatal outcomes. The multivariable model was adjusted for potential confounders.

Results

Among singleton pregnancies, compared with spontaneous pregnancies, IVF pregnancies were associated with significant increases in the rates of the following: gestational diabetes mellitus (GDM) (aOR 1.76[95% CI 1.33–2.33]), preeclampsia (2.60[1.61–4.20]), preterm preeclampsia (4.52[2.03–10.06]), postpartum hemorrhage (1.57[1.04–2.36]), intrahepatic cholestasis of pregnancy (3.84[1.06–13.94]), preterm premature rupture of membranes (2.11[1.17–3.81]), preterm birth (1.95[CI 1.26–3.01]), low birthweight (1.90[1.13–3.20]), macrosomia (1.53[1.03–2.27]), and neonatal intensive care unit (NICU) admission (1.69[1.22–2.34]) in the ovulation disorder group; GDM (1.50[1.21–1.86]), placenta previa (2.70[1.59–4.59]), placenta accreta (1.78[1.10–2.89]), postpartum hemorrhage (1.61[1.19–2.18]), macrosomia (1.60[1.21–2.13]) and 5-min Apgar score ≤ 7 (4.09[1.04–16.08]) in the tubal disease group; placenta previa (9.33[4.22–20.62]), small for gestational age (2.29[1.04–5.08]), macrosomia (2.00[1.02–3.95]) and NICU admission (2.35[1.35–4.09]) in the endometriosis group; placenta previa (4.14[2.23–7.68]) and placenta accreta (2.05[1.08–3.87]) in the male infertility group; and GDM (1.85[1.15–2.98]), placenta previa (4.73[1.83–12.21]), placental abruption (3.39[1.20–9.56]), chorioamnionitis (2.93[1.04–8.26]), preterm birth (2.69[1.41–5.15]), and 1-min Apgar score ≤ 7 (4.68[1.62–13.51]) in the mixed infertility group. Among multiple pregnancies, most of the differences that were significant in singleton pregnancies were less extensive or had disappeared.

Conclusions

Infertility etiology within the IVF population was found to affect maternal and neonatal outcomes among all births. During the perinatal period, infertility etiology appears to be an additional risk factor for abnormal pregnancy outcomes besides the use of IVF techniques compared with spontaneous pregnancies. Higher risk was found for ovulation disorders, and lower risk was found for male infertility.

Birthweight of IVF children is still a current issue and still related to maternal factors

RESEARCH QUESTION

Does fresh embryo transfer after IVF with or without intracytoplasmic sperm injection (ICSI) increase the small for gestational age (SGA) rate, and frozen embryo transfer (FET) after IVF with or without ICSI increase the large for gestational age (LGA) rate versus natural conception?

DESIGN

Retrospective comparison of an exposed historical group/cohort involving singletons conceived after fresh embryo transfer and after FET with an unexposed group/cohort involving singletons conceived after a natural conception.

RESULTS

A total of 1961 fresh embryo transfer babies and 366 FET babies were compared with 6981 natural conception babies. The SGA rate in fresh embryo transfer babies was not significantly different to natural conception babies (6.9% versus 6.8%, P = 0.856). This outcome was not influenced by the fresh embryo transfer (adjusted odds ratio [aOR] 1.0; 95% confidence interval [CI] 0.8-1.3), but rather by a low rate of multiparity (aOR 0.5; 95% CI 0.3-0.7), advanced maternal age (aOR 1.1; 95% CI 1.0-1.2), maternal underweight (aOR 1.5; 95% CI 1.1-2.1), maternal smoking or cessation during pregnancy (aOR 1.8; 95% CI 1.4-2.3), pre-existing hypertension (aOR 2.3; 95% CI 1.3-4.1) and pregnancy-induced hypertension (aOR 2.5; 95% CI 1.7-3.7). The LGA rate in FET babies was significantly different from natural conception babies (6.6% versus 3.2%, P = 0.012). This outcome was influenced by the transfer of frozen embryos (aOR 2.2; 95% CI 1.3-3.8) and by a high maternal weight (aOR 1.9; 95% CI 1.1-3.6).

CONCLUSIONS

Maternal background and obstetric parameters are more likely to influence the SGA rate than fresh embryo transfer conception. FET conception could be associated with an increase in LGA rate.

Maternal and Fetal Risk Associated With Assisted Reproductive Technology

Infertility is a disease that affects up to 15.5% of reproductive-aged couples. Until the birth of the first neonate born from in vitro fertilization (IVF) in 1978, many infertile couples did not have an opportunity to conceive a biological child. Over the past 40 years, access to and effectiveness of IVF have increased; currently 1.7% of births in the United States result from IVF. As with any medical intervention, potential risk exists. In the case of IVF, both maternal risks (ovarian stimulation, oocyte retrieval, and subsequent pregnancy) and fetal risks that vary based on maternal age and fetal number must be considered. Importantly, risk quantification varies by comparison group, which is typically either spontaneous conception in a fertile couple or assisted non-IVF conception in an infertile couple. It must also be considered compared with the alternative of not undergoing IVF, which may mean not having a biological child. Although increased compared with spontaneous conception, absolute maternal-fetal-assisted reproductive technology risks are low and can be minimized by optimizing ovarian stimulation and transferring a single embryo. In this article, we aim to summarize maternal and fetal risk associated with use of assisted reproductive technology. The review focuses on ovarian stimulation and procedural risks as well as adverse perinatal outcomes among resultant singleton and twin pregnancies in young women and women of advanced maternal age.

Differences in First-Trimester Maternal Metabolomic Profiles in Pregnancies Conceived From Fertility Treatments

CONTEXT

Maternal metabolic status reflects underlying physiological changes in the maternal-placental-fetal unit that may help identify contributors to adverse pregnancy outcomes associated with infertility and treatments used.

OBJECTIVE

To determine if maternal metabolomic profiles differ between spontaneous pregnancies and pregnancies conceived with fertility treatments that may explain the differences in pregnancy outcomes.

DESIGN

Metabolon metabolomic analysis and ELISAs for 17-β-estradiol and progesterone were performed during the late first trimester of pregnancy.

SETTING

Academic institution.

SUBJECTS

Women in the Spontaneous/Medically Assisted/Assisted Reproductive Technology cohort (N = 409), 208 of whom conceived spontaneously and 201 with infertility [non in vitro fertilization treatments (NIFT), n=90; in vitro fertilization (IVF), n=111].

INTERVENTION

Mode of conception.

MAIN OUTCOME MEASURES

Levels of of 806 metabolites within eight superpathways, 17-β-estradiol, and progesterone in maternal plasma in the late first trimester.

RESULTS

Metabolomic differences in the lipid superpathway (i.e., steroid metabolites, lipids with docosahexaenoyl acyl chains, acyl cholines), and xanthine and benzoate metabolites (P < 0.05) were significant among the spontaneous and two infertility groups, with greatest differences between the spontaneous and IVF groups. 17-β-estradiol and progesterone levels were significantly elevated in the infertility groups, with greatest differences between the spontaneous and IVF groups.

CONCLUSION

Metabolomic profiles differ between spontaneous and infertility pregnancies, likely driven by IVF. Higher levels of steroids and their metabolites are likely due to increased hormone production from placenta reprogrammed from fertility treatments, which may contribute to adverse outcomes associated with infertility and the treatments used.

Medically assisted reproduction and birth outcomes: a within-family analysis using Finnish population registers

BACKGROUND

Children born after medically assisted reproduction are at higher risk of adverse birth outcomes than are children conceived naturally. We aimed to establish the extent to which this excess risk should be attributed to harmful effects of treatment or to pre-existing parental characteristics that confound the association.

METHODS

We used data from Finnish administrative registers covering a 20% random sample of households with at least one child aged 0-14 years at the end of 2000 (n=65 723). We analysed birthweight, gestational age, risk of low birthweight, and risk of preterm birth among children conceived both by medically assisted reproduction and naturally. First, we estimated differences in birth outcomes by mode of conception in the general population, using standard multivariate methods that controlled for observed factors (eg, multiple birth, birth order, and parental sociodemographic characteristics). Second, we used a sibling-comparison approach that has not been used before in medically assisted reproduction research. We compared children conceived by medically assisted reproduction with siblings conceived naturally and, thus, controlled for all observed and unobserved factors shared by siblings.

FINDINGS

Between 1995 and 2000, 2776 (4%) children in our sample were conceived by medically assisted reproduction; 1245 children were included in the sibling comparison. Children conceived by medically assisted reproduction had worse outcomes than did those conceived naturally, for all outcomes, even after adjustments for observed child and parental characteristics-eg, difference in birthweight of -60 g (95% CI -86 to -34) and 2·15 percentage point (95% CI 1·07 to 3·24) increased risk of preterm delivery. In the sibling comparison, the gap in birth outcomes was attenuated, such that the relation between medically assisted reproduction and adverse birth outcomes was statistically and substantively weak for all outcomes-eg, difference in birthweight of -31 g (95% CI -85 to 22) and 1·56 percentage point (95% CI -1·26 to 4·38) increased risk of preterm delivery.

INTERPRETATION

Children conceived by medically assisted reproduction face an elevated risk of adverse birth outcomes. However, our results indicate that this increased risk is largely attributable to factors other than the medically assisted reproduction treatment itself.

FUNDING

European Research Council, the Academy of Finland, and the Signe and Ane Gyllenberg Foundation.

Factors associated with increased odds of cesarean delivery in ART pregnancies

OBJECTIVE

To quantify the effect of medical and obstetrical factors on the odds of cesarean delivery, comparing assisted reproductive technology (ART)-treated women and women with subfertility not treated with ART versus fertile women.

DESIGN

Retrospective cohort.

SETTING

Not applicable.

PATIENT(S)

Singleton deliveries to primiparous women; with the source of this data being the Massachusetts vital and hospital records linked to the Society for Assisted Reproductive Technology Clinic Outcome Reporting System data (2004-2010).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Mode of delivery.

RESULT(S)

The 173,130 deliveries included 5,768 ART-treated, 2,657 subfertile (1,627 non-ART medically assisted reproduction [MAR] and 1,030 unassisted infertile), and 164,705 fertile pregnancies and 117,743 vaginal and 55,387 cesarean deliveries. ART-treated women were older, more often white and non-Hispanic, and with more private insurance, previous uterine surgery, gestational diabetes, pregnancy hypertension, bleeding, and placental complications than fertile women. Overall rates of cesarean delivery were 45.7%, 43.3%, and 31.1% for ART-treated, subfertile, and fertile women and 41.7% and 45.9% for MAR and unassisted infertile deliveries. When adjusted for demographics, underlying medical factors, previous uterine surgery, and placental and delivery complications, adjusted odds ratios (ORs) compared with fertile women were 1.27 for ART-treated and 1.15 for subfertile women, with greater odds among unassisted infertile (OR 1.26) but not MAR (OR 1.09) women. The strongest confounders of odds of cesarean delivery were age and previous uterine surgery.

CONCLUSION(S)

ART and unassisted infertility were associated with greater odds of cesarean compared with fertile women. Underlying medical and obstetrical risks had strong confounding effects strongly attenuating the odds for cesarean delivery.

In vitro fertilization alters phospholipid profiles in mouse placenta

PURPOSE

Studies on humans and rodents have clearly shown that in vitro fertilization (IVF) is associated with abnormal placenta formation and function. Currently, dysregulated placental lipid metabolism is one of the emerging pathogenetic pathways implicated in adverse pregnancy outcomes. The purpose of this study was to identify the effects of IVF on lipid metabolism in the mouse placenta.

METHODS

Two groups of mouse placentas, composed of control and IVF, were collected at embryonic day 18.5. Placental lipid profiles were measured using liquid chromatography coupled with mass spectrometry. The relative levels of individual lipid were examined and compared. The proteins and enzymes that regulate the phospholipid biosynthesis were also compared by western blot.

RESULTS

A significant increase in levels of phosphatidylcholines, phosphatidylethanolamines, phosphatidylinositols, phosphatidylglycerols, lysophosphatidylcholines, and mitochondrial cardiolipin were found in the IVF placenta. In addition, proteins and enzymes that regulate the phospholipid biosynthesis were also altered in IVF placentas.

CONCLUSIONS

After lipidomic analysis, we present the first detailed overview of the effect of IVF on lipid metabolism, especially phospholipid profiles in the placenta in a mouse model. The widespread lipidomic shifts identified in this study might explicate some of the placental dysfunction observed after IVF, thereby illustrating that phospholipids serve as early warning biomarkers of health risks in IVF offspring.

In vitro fertilization, interpregnancy interval, and risk of adverse perinatal outcomes

OBJECTIVE

To compare associations between interpregnancy intervals (IPIs) and adverse perinatal outcomes in deliveries following IVF with deliveries following spontaneous conception or other (non-IVF) fertility treatments.

DESIGN

Cohort using linked birth certificate and assisted reproductive technology surveillance data from Massachusetts and Michigan.

SETTING

Not applicable.

PATIENT(S)

1,225,718 deliveries.

INTERVENTION(S)

None.

MAIN OUTCOMES MEASURE(S)

We assessed associations between IPI and preterm birth (PTB), low birth weight (LBW), and small for gestational age (SGA) according to live birth or nonlive pregnancy outcome in the previous pregnancy.

RESULT(S)

In IVF deliveries following previous live birth, risk of PTB was 22.2% for IPI 12 to <24 months (reference); risk of PTB was higher for IPI <12 months (adjusted relative risk [aRR] 1.24, 95% confidence interval [CI] 1.09-1.41) and IPI ≥60 months (aRR 1.12, 95% CI 1.00-1.26). In non-IVF deliveries following live birth, risk of PTB was 6.4% for IPI 12 to <24 months (reference); risk of PTB was higher for IPI <12 and ≥60 months (aRR 1.19, 95% CI 1.16-1.21, for both). In both populations, U-shaped or approximately U-shaped associations were observed for SGA and LBW, although the association of IPI <12 months and SGA was not significant in IVF deliveries. In IVF and non-IVF deliveries following nonlive pregnancy outcome, IPI <12 months was not associated with increased risk of PTB, LBW, or SGA, but IPI ≥60 months was associated with significant increased risk of those outcomes in non-IVF deliveries.

CONCLUSION(S)

Following live births, IPIs <12 or ≥60 months were associated with higher risks of most adverse perinatal outcomes in both IVF and non-IVF deliveries.

Birth outcomes of singleton vaginal deliveries to ART-treated, subfertile, and fertile primiparous women

PURPOSE

To determine whether differences in birth outcomes among assisted reproductive technology (ART)-treated, subfertile, and fertile women exist in primiparous women with, singleton, vaginal deliveries.

METHODS

Society for Assisted Reproductive Technology Clinic Outcome Reporting System (SART CORS) data were linked to Massachusetts vital records and hospital discharges for deliveries between July 2004 and December 2010. Primiparous women with in-state vaginal deliveries, adequate prenatal care, and singleton birth at ≥ 20 weeks (n = 117,779) were classified as ART-treated (linked to ART data from SART CORS, n = 3138); subfertile (not ART-treated but with indicators of subfertility, n = 1507); or fertile (neither ART-treated nor subfertile, n = 113,134). Outcomes of prematurity (< 37 weeks), low birthweight (< 2500 g), perinatal death (death at ≥ 20 weeks to ≤ 7 days), and maternal prolonged length of hospital stay (LOS > 3 days) were compared using multivariable logistic regression.

RESULTS

Compared to fertile, higher odds were found for prematurity among ART-treated (adjusted odds ratio [AOR] 1.40, 95% confidence interval [CI] 1.25-1.50) and subfertile (AOR 1.25, 95% CI 1.03-1.50) women, low birthweight among ART-treated (AOR 1.41, 95% CI 1.23-1.62) and subfertile (AOR 1.40, 95% CI 1.15-1.71) women, perinatal death among subfertile (AOR 2.64, 95% CI 1.72-4.05), and prolonged LOS among ART-treated (AOR 1.33, 95% CI 1.19-1.48) women. Differences remained despite stratification by young age and absence of pregnancy/delivery complications.

CONCLUSIONS

Greater odds of prematurity and low birthweight in ART-treated and subfertile, and perinatal death in subfertile deliveries are evident among singleton vaginal deliveries. The data suggest that even low-risk pregnancies to ART-treated and subfertile women be managed for adverse outcomes.

Clinical review of 24-35 year olds conceived with and without in vitro fertilization: study protocol

Background

Children conceived by assisted reproductive technologies (ART) currently comprise 4% of Australian births. The manipulation of biological parameters related to fertilization and implantation are integral to successful ART but potentially pose a risk to the longer-term health of the offspring. There is consensus that many common adult health problems (particularly cardiovascular, metabolic and respiratory conditions) have their origins in early life, possibly before birth, and that risk trajectories track through childhood until clinical disease manifests in adulthood. Early life epigenetic variation may play a role in this process. However little is known about the long-term health of individuals conceived by ART. In a previous study, based on telephone-interviews, we found that young adults conceived by in vitro fertilization (IVF) had significantly more maternal reported atopic respiratory, endocrine, nutritional, and metabolic conditions than non-IVF conceived matched controls. Here we outline the protocol for a follow-up biomedical assessment of this cohort and a questionnaire to obtain information on potential confounders.

Methods

We are conducting a clinical review of an existing, well characterised cohort comprising 547 IVF-conceived adults and 549 matched controls. We are measuring cardiovascular intermediate phenotypes, metabolic parameters and respiratory function, complemented by epigenome-wide DNA methylation analysis. A pilot study demonstrated the feasibility of our proposed protocol and its acceptability to participants. Participants attend a 2–3 h clinical assessment and complete a study-specific online questionnaire. Measurements include: 1) cardiovascular phenotypes: carotid artery intima-media thickness and distensibility, retinal vascular calibre, resting blood pressure, pulse wave velocity and pulse wave analysis; 2) respiratory function: spirometry, plethysmography, multiple breath washout; 3) auxology: height, weight, waist circumference, bio-impedance. Blood is collected for 4) biomarkers of cardiometabolic profile including inflammatory markers and 5) epigenetic analysis.

Discussion

Recruitment for this clinical review is challenging as many of the participants have moved to regional, interstate or international locations. Additionally, many female participants are pregnant or breastfeeding, and are therefore ineligible. Nevertheless, comprehensive strategies have been developed to optimize recruitment. Given the increasing use of IVF and related technologies, the potential long-term consequences for risk of common adult diseases is an important clinical and public health issue.

Perinatal outcomes among singletons after assisted reproductive technology with single-embryo or double-embryo transfer versus no assisted reproductive technology

OBJECTIVE

To examine outcomes of singleton pregnancies conceived without assisted reproductive technology (non-ART) compared with singletons conceived with ART by elective single-embryo transfer (eSET), nonelective single-embryo transfer (non-eSET), and double-embryo transfer with the establishment of 1 (DET -1) or ≥2 (DET ≥2) early fetal heartbeats.

DESIGN

Retrospective cohort using linked ART surveillance data and vital records from Florida, Massachusetts, Michigan, and Connecticut.

SETTING

Not applicable.

PATIENT(S)

Singleton live-born infants.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Preterm birth (PTB <37 weeks), very preterm birth (VPTB <32 weeks), small for gestational age birth weight (<10th percentile), low birth weight (LBW <2,500 g), very low birth weight (VLBW <1,500 g), 5-minute Apgar score <7, and neonatal intensive care unit (NICU) admission.

RESULT(S)

After controlling for maternal characteristics and employing a weighted propensity score approach, we found that singletons conceived after eSET were less likely to have a 5-minute Apgar <7 (adjusted odds ratio [aOR] 0.33; 95% CI, 0.15-0.69) compared with non-ART singletons. There were no differences among outcomes between non-ART and non-eSET infants. We found that PTB, VPTB, LBW, and VLBW were more likely among DET -1 and DET ≥2 compared with non-ART infants, with the odds being higher for DET ≥2 (PTB aOR 1.58; 95% CI, 1.09-2.29; VPTB aOR 2.46; 95% CI, 1.20-5.04; LBW aOR 2.17; 95% CI, 1.24-3.79; VLBW aOR 3.67; 95% CI, 1.38-9.77).

CONCLUSION(S)

Compared with non-ART singletons, singletons born after eSET and non-eSET did not have increased risks whereas DET -1 and DET ≥2 singletons were more likely to have adverse perinatal outcomes.

Risk of adverse pregnancy and perinatal outcomes after high technology infertility treatment: a comprehensive systematic review

In the literature, there is growing evidence that subfertile patients who conceived after infertility treatments have an increased risk of pregnancy and perinatal complications and this is particularly true for patients who conceived through use of high technology infertility treatments. Moreover, high technology infertility treatments include many concomitant clinical and biological risk factors. This review aims to summarize in a systematic fashion the current evidence regarding the relative effect of the different procedures for high technology infertility treatments on the risk of adverse pregnancy and perinatal outcome. A literature search up to August 2016 was performed in IBSS, SocINDEX, Institute for Scientific Information, PubMed, Web of Science and Google Scholar and an evidence-based hierarchy was used to determine which articles to include and analyze. Data on prepregnancy maternal factors, low technology interventions, specific procedures for male factor, ovarian tissue/ovary and uterus transplantation, and chromosomal abnormalities and malformations of the offspring were excluded. The available evidences were analyzed assessing the level and the quality of evidence according to the Oxford Centre for Evidence-Based Medicine guidelines and the Grading of Recommendations Assessment, Development, and Evaluation system, respectively. Current review highlights that every single procedure of high technology infertility treatments can play a crucial role in increasing the risk of pregnancy and perinatal complications. Due to the suboptimal level and quality of the current evidence, further well-designed studies are needed.