High maternal serum estradiol environment in the first trimester is associated with the increased risk of small-for-gestational-age birth

Effect of estrogen exposure on pregnancy outcomes in artificial frozen-thawed embryo transfer cycles

In contemporary times, the employment of vitrification freezing technology has led to the widespread adoption of frozen-thawed embryo transfer (FET) worldwide. Meanwhile, hormone replacement therapy (HRT) is a crucial protocol for priming the endometrium during FET cycles. Estrogen is required in HRT cycles for the induction of progesterone receptors and to promote endometrial thickness. However, there is no universal consensus on the treatment duration, dosage regimen, administration route, and target serum estrogen levels. Therefore, this study aimed to offer a comprehensive review of these topics. A shorter duration of estrogen exposure may elevate the risk of early miscarriage, while prolonged exposure to estrogen does not seem to confer advantages to general population and may be attempted in individuals with thin endometrium. Moreover, excessive estrogen levels on the day of progesterone administration may be associated with higher miscarriage rates and lower live birth rates (LBR). To offer more comprehensive guidance for clinical practice, extensive and prospective studies involving a large sample size are warranted to determine the optimal concentration and duration of estrogen exposure.

The High Estradiol Environment after IVF Causes the Increased Risk of Glucose Metabolic Dysfunction in Offspring

CONTEXT

Assisted reproductive technology (ART) is associated with increased metabolic risks in offspring. The effect of high maternal estradiol (E2) levels during early pregnancy on the glucose metabolism of offspring remains unclear.

OBJECTIVE

To evaluate glucose metabolism in in vitro fertilization (IVF)-conceived children and assess whether high E2 exposure during early pregnancy is associated with metabolic alterations.

DESIGN/SETTING/PARTICIPANTS

This retrospective analysis included 500 singletons aged 3-10 years born after fresh embryo transfer (ET) (n=200), frozen ET (n=100), and natural conception (NC) (n=200) from a university hospital.

METHODS

Children underwent anthropometric measurements and examinations for fasting glucose, insulin, and lipid levels. A mouse model of high E2 exposure during early pregnancy was established to study glucose and insulin tolerance, and insulin secretion.

RESULTS

Compared with NC, children born after fresh ET showed higher fasting glucose/insulin levels, increased insulin resistance, and higher incidence of impaired fasting glucose, which might be associated with a higher maternal E2 levels. Frozen ET showed intermediate results. In mice, offspring exposed to high E2 levels during gestation exhibited impaired glucose/insulin tolerance and defects in insulin secretion.

CONCLUSION

High maternal E2 levels in early pregnancy are associated with altered glucose metabolism and increased metabolic risks in IVF-conceived children. Further studies are needed to elucidate the underlying mechanisms.

Impact of elevated serum estradiol levels before progesterone administration on pregnancy outcomes in frozen-thawed embryo transfer for hormone replacement therapy

OBJECTIVE

The objective of this retrospective cohort study is to investigate the impact of monitoring serum estradiol (E2) levels before progesterone administration within hormone replacement therapy (HRT) on pregnancy outcomes in women undergoing frozen-thawed embryo transfer (FET).

METHODS

Analyzed HRT-FET cycles conducted at a reproductive center from 2017 to 2022. Serum E2 levels were measured prior to progesterone administration. Multivariate stratified and logistic regression analyses were performed on 26,194 patients grouped according to terciles of serum E2 levels before progesterone administration.

RESULTS

The clinical pregnancy rate (CPR) and live birth rate (LBR) exhibited a gradual decline with increasing serum E2 levels across the three E2 groups. Even after controlling for potential confounders, including female age, body mass index, infertility diagnosis, cycle category, number of embryos transferred, fertilization method, indication for infertility, and endometrial thickness, both CPR and LBR persistently showed a gradual decrease as serum E2 levels increased within the three E2 groups. The same results were obtained by multivariate logistic regression analysis.

CONCLUSIONS

This large retrospective study indicates that elevated serum E2 levels before progesterone administration during HRT-FET cycles are associated with reduced CPR and LBR post-embryo transfer. Therefore, it is advisable to monitor serum E2 levels and adjust treatment strategies accordingly to maximize patient outcomes.

The difference in early trimester fetal growth between singletons after frozen embryo transfer and fresh embryo transfer

BACKGROUND

Frozen embryo transfer resulted in a higher birthweight and an increased risk of macrosomia than fresh embryo transfer. However, the mechanism was still unclear. When the impact of frozen embryo transfer on fetal growth began was unknown. Crown-rump length at 11-13 weeks had been regarded as a good indicator of fetal growth in the first trimester and had been used for gestational age calculation in women with uncertain last menstrual periods.

OBJECTIVE

To evaluate the association between frozen embryo transfer and early fetal growth, particularly the crown-rump length, then fresh embryo transfer. The secondary objective was to investigate the potential correlation between crown-rump length and birthweight.

STUDY DESIGN

This was a retrospective cohort study conducted at the Reproductive Medical Center of Shandong University. A total of 4949 patients who obtained singleton pregnancy after frozen embryo transfer and 1793 patients who got singleton pregnancy after fresh embryo transfer between January 1, 2017 and December 31, 2022 were included. The primary outcome was the crown-rump length measured via ultrasound at 11-13 weeks gestation. The secondary outcomes were perinatal outcomes, including birthweight and the risk of large for gestational age, small for gestational age, macrosomia, low birthweight, and premature delivery. Multivariable linear regression models were used to adjust for potential confounders of crown-rump length.

RESULTS

A total of 6742 live singleton births after frozen embryo transfer or fresh embryo transfer were included in this study. In the univariable analysis, the frozen embryo transfer group had a larger crown-rump length (5.75±0.53 cm vs 5.57±0.48 cm, P<.001) and an increased risk of larger-than-expected crown-rump length (13.5% vs11.2%, P=.013) than the fresh embryo transfer group. After adjusting for confounders in multivariable linear regression models, frozen embryo transfer was still associated with a larger crown-rump length (regression coefficient, 3.809 [95% confidence intervals, 3.621-3.997], P<.001). When subgrouped by fetal gender, the crown-rump length of the frozen embryo transfer group was larger than the fresh embryo transfer group in both male and female fetuses. In addition, the crown-rump length was consistently larger in the frozen embryo transfer group than the fresh embryo transfer group in subgroups of the peak estradiol levels. The comparisons among different crown-rump length groups showed that smaller-than-expected crown-rump length was associated with increased risks of small for gestational age (6.3% vs 3.0%, P<.001) and preterm delivery (9.6% vs 6.7%, P=.004) than normal crown-rump length.

CONCLUSION

Frozen embryo transfer was associated with a larger crown-rump length than fresh embryo transfer, suggesting that the effect of frozen embryo transfer on fetal growth may begin in the early trimester. Suboptimal fetal growth in the first trimester may be associated with low birthweight and premature delivery.

Aptasensor-encapsulating semi-permeable proteinosomes for direct target detection in non-treated biofluids

Detecting biomarkers in biofluids directly without sample treatments makes molecular diagnostics faster and more efficient. Aptasensors, the nucleic acid-based molecular biosensors, can detect a wide range of target molecules, but their susceptibility to degradation and aggregation by nucleases and charged proteins, respectively, limits their direct use in clinical samples. In this work, we demonstrate that when aptasensors are encapsulated in proteinosomes, the protein-based liposome mimics, clinically important small molecules can be sensitively and selectively detected in non-treated specimens, such as 100 % unpurified serum. As serum albumin is used to form the membrane, the nanomeshed proteinosomes become semi-permeable and antifouling, which enables exclusive admission of small molecules while blocking unwanted large proteins. Consequently, the enclosed aptasensors can maintain close-to-optimal performance for target binding, and nucleolytic degradation and electrostatic aggregation are effectively suppressed. Three different structure-switching aptamers specific for estradiol, dopamine, and cocaine, respectively, are demonstrated to fully conserve their high affinities and specificities inside the microcapsules. The shielding effect of proteinosomes is indeed exceptional; the enclosed DNA aptasensors remain completely intact over 18 h in serum and even in an extremely concentrated DNase solution (1 mg/ml, ∼300,000× the serum level). Moreover, the proteinosome-mediated compartmentalization enables independent operation of multiple aptasensors in the same mixture. Hence, simultaneous real-time sensing of two different targets is demonstrated with different operation modes, 'recording' target appearance and 'reporting' target concentration changes. This work is the first demonstration of small-molecule-specific aptasensors operating with optimal performance in serum environments and will find promising applications in molecular diagnostics.

Long-term health risk of offspring born from assisted reproductive technologies

Since the world's first in vitro fertilization baby was born in 1978, there have been more than 8 million children conceived through assisted reproductive technologies (ART) worldwide, and a significant proportion of them have reached puberty or young adulthood. Many studies have found that ART increases the risk of adverse perinatal outcomes, including preterm birth, low birth weight, small size for gestational age, perinatal mortality, and congenital anomalies. However, data regarding the long-term outcomes of ART offspring are limited. According to the developmental origins of health and disease theory, adverse environments during early life stages may induce adaptive changes and subsequently result in an increased risk of diseases in later life. Increasing evidence also suggests that ART offspring are predisposed to an increased risk of non-communicable diseases, such as malignancies, asthma, obesity, metabolic syndrome, diabetes, cardiovascular diseases, and neurodevelopmental and psychiatric disorders. In this review, we summarize the risks for long-term health in ART offspring, discuss the underlying mechanisms, including underlying parental infertility, epigenetic alterations, non-physiological hormone levels, and placental dysfunction, and propose potential strategies to optimize the management of ART and health care of parents and children to eliminate the associated risks. Further ongoing follow-up and research are warranted to determine the effects of ART on the long-term health of ART offspring in later life.

High estrogen during ovarian stimulation induced loss of maternal imprinted methylation that is essential for placental development via overexpression of TET2 in mouse oocytes

BACKGROUND

Ovarian stimulation (OS) during assisted reproductive technology (ART) appears to be an independent factor influencing the risk of low birth weight (LBW). Previous studies identified the association between LBW and placenta deterioration, potentially resulting from disturbed genomic DNA methylation in oocytes caused by OS. However, the mechanisms by which OS leads to aberrant DNA methylation patterns in oocytes remains unclear.

METHODS

Mouse oocytes and mouse parthenogenetic embryonic stem cells (pESCs) were used to investigate the roles of OS in oocyte DNA methylation. Global 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC) levels were evaluated using immunofluorescence or colorimetry. Genome-wide DNA methylation was quantified using an Agilent SureSelectXT mouse Methyl-Seq. The DNA methylation status of mesoderm-specific transcript homologue (Mest) promoter region was analyzed using bisulfite sequencing polymerase chain reaction (BSP). The regulatory network between estrogen receptor alpha (ERα, ESR1) and DNA methylation status of Mest promoter region was further detected following the knockdown of ERα or ten-eleven translocation 2 (Tet2).

RESULTS

OS resulted in a significant decrease in global 5mC levels and an increase in global 5hmC levels in oocytes. Further investigation revealed that supraphysiological β-estradiol (E2) during OS induced a notable decrease in DNA 5mC and an increase in 5hmC in both oocytes and pESCs of mice, whereas inhibition of estrogen signaling abolished such induction. Moreover, Tet2 may be a direct transcriptional target gene of ERα, and through the ERα-TET2 axis, supraphysiological E2 resulted in the reduced global levels of DNA 5mC. Furthermore, we identified that MEST, a maternal imprinted gene essential for placental development, lost its imprinted methylation in parthenogenetic placentas originating from OS, and ERα and TET2 combined together to form a protein complex that may promote Mest demethylation.

CONCLUSIONS

In this study, a possible mechanism of loss of DNA methylation in oocyte caused by OS was revealed, which may help increase safety and reduce epigenetic abnormalities in ART procedures.

A mutual comparison of pregnancy outcomes between different conception modes: a propensity score matching based retrospective cohort study

Background

Assisted reproductive technology (ART) has been reported to have negative effects on maternal and neonatal health. Ovulation induction (OI) was reported to be associated with alteration of epigenetic modification of mice embryos, and extinguishing the influence of ovulation induction and in vitro operations on maternal and neonatal health will bring benefits for reducing side effects. The present study aimed to determine whether ovulation induction alone and ART are associated with adverse pregnancy outcomes and whether ART could induce a higher risk than ovulation induction alone.

Methods

A total of 51,172 cases with singleton live birth between Jan 2016 and May 2019 at the International Peace Maternal and Child Health Hospital were included in this study. Conception modes documented during registration were classified into natural conception (NC), OI, and ART. Pregnancy outcomes of the three groups with balanced baseline characteristics by propensity score matching were compared. The relative risks of maternal and neonatal outcomes were calculated by logistic regression analysis.

Results

Compared with natural conception, infertility treatments are associated with gestational diabetes (OI: OR 1.72, 95% CI 1.31-2.27; ART: OR 1.67, 95% CI 1.26-2.20), preeclampsia/eclampsia (OI: OR 1.86, 95% CI 1.03-3.36; ART: OR 2.23, 95% CI 1.26-3.92). Even if gestational diabetes, gestational hypertension, and placental problems were adjusted, infertility treatments are associated with birth before 37 weeks (OI: OR 1.99, 95% CI 1.28-3.12; ART: OR 1.70, 95% CI 1.08-2.69), low birth weight (OI: OR 2.19, 95% CI 1.23-3.91; ART: OR 1.90, 95% CI 1.05-3.45), and SGA (OI: OR 2.42, 95% CI 1.20-4.87; ART: OR 2.56, 95% CI 1.28-5.11). ART but not OI is associated with a higher risk of birth before 34 weeks (OR:3.12, 95% CI 1.21-8.05). By comparing the OI group with the ART group, we only found that ART could induce a higher ratio of placental problems (5.0%, 26/518 vs 2.1%, 11/519, p<0.05).

Conclusion

Both OI and ART are associated with adverse pregnancy outcomes. ART induced comparable negative effects with OI on gestational complications, birth weight, and premature birth (<37 weeks). However, ART resulted in a higher risk of placental problems than group NC and OI. The incidence of birth before 34 weeks of gestation in the ART group tends to be higher than in the OI group, but not statistically significant. The side effects of ART may originate from OI.

The pathophysiological role of estrogens in the initial stages of pregnancy: molecular mechanisms and clinical implications for pregnancy outcome from the periconceptional period to end of the first trimester

BACKGROUND

Estrogens regulate disparate female physiological processes, thus ensuring reproduction. Altered estrogen levels and signaling have been associated with increased risks of pregnancy failure and complications, including hypertensive disorders and low birthweight babies. However, the role of estrogens in the periconceptional period and early pregnancy is still understudied.

OBJECTIVE AND RATIONALE

This review aims to summarize the current evidence on the role of maternal estrogens during the periconceptional period and the first trimester of pregnancies conceived naturally and following ART. Detailed molecular mechanisms and related clinical impacts are extensively described.

SEARCH METHODS

Data for this narrative review were independently identified by seven researchers on Pubmed and Embase databases. The following keywords were selected: 'estrogens' OR 'estrogen level(s)' OR 'serum estradiol' OR 'estradiol/estrogen concentration', AND 'early pregnancy' OR 'first trimester of pregnancy' OR 'preconceptional period' OR 'ART' OR 'In Vitro Fertilization (IVF)' OR 'Embryo Transfer' OR 'Frozen Embryo Transfer' OR 'oocyte donation' OR 'egg donation' OR 'miscarriage' OR 'pregnancy outcome' OR 'endometrium'.

OUTCOMES

During the periconceptional period (defined here as the critical time window starting 1 month before conception), estrogens play a crucial role in endometrial receptivity, through the activation of paracrine/autocrine signaling. A derailed estrogenic milieu within this period seems to be detrimental both in natural and ART-conceived pregnancies. Low estrogen levels are associated with non-conception cycles in natural pregnancies. On the other hand, excessive supraphysiologic estrogen concentrations at time of the LH peak correlate with lower live birth rates and higher risks of pregnancy complications. In early pregnancy, estrogen plays a massive role in placentation mainly by modulating angiogenic factor expression-and in the development of an immune-tolerant uterine micro-environment by remodeling the function of uterine natural killer and T-helper cells. Lower estrogen levels are thought to trigger abnormal placentation in naturally conceived pregnancies, whereas an estrogen excess seems to worsen pregnancy development and outcomes.

WIDER IMPLICATIONS

Most current evidence available endorses a relation between periconceptional and first trimester estrogen levels and pregnancy outcomes, further depicting an optimal concentration range to optimize pregnancy success. However, how estrogens co-operate with other factors in order to maintain a fine balance between local tolerance towards the developing fetus and immune responses to pathogens remains elusive. Further studies are highly warranted, also aiming to identify the determinants of estrogen response and biomarkers for personalized estrogen administration regimens in ART.

The Association between Early Menarche and Small for Gestational Age Birth

In the U.S., approximately 11% of infants are born small for gestational age (SGA). While there are many known behavioral risk factors for SGA births, there are still many factors yet to be explored. The purpose of this study was to investigate the maternal early menarche (< 12 years old)- SGA birth association. Data were retrieved from the 2011-2017 National Survey of Family Growth, and multivariate logistic regression was used to evaluate the association. Approximately 4% of mothers reported having an SGA infant and 24% of mothers reported early age at menarche. After controlling for maternal age, race/ethnicity, and annual household income, early menarche was associated with 3% increased odds of SGA, although this finding was not statistically significant (adjusted odds ratio: 1.03, 95% CI: 0.70, 1.53). Additional research is needed on the long-term birth outcomes and health consequences of early menarche.

Associations of periconceptional oral contraceptive use with pregnancy complications and adverse birth outcomes

BACKGROUND

Periconceptional use of oral contraceptives (OCs) has been reported to increase risks of pregnancy complications and adverse birth outcomes, but risks are suggested to differ depending on the timing of discontinuation, amount of oestrogen and progestin content.

METHODS

Prospective cohort study among 6470 pregnancies included in the PRegnancy and Infant DEvelopment (PRIDE) Study in 2012-19. Exposure was defined as any reported use of OCs within 12 months pre-pregnancy or after conception. Outcomes of interest were gestational diabetes, gestational hypertension, pre-eclampsia, pre-term birth, low birthweight and small for gestational age (SGA). Multivariable Poisson regression using stabilized inverse probability weighting estimated relative risks (RRs) with 95% CIs.

RESULTS

Any periconceptional OC use was associated with increased risks of pre-eclampsia (RR 1.38, 95% CI 0.99-1.93), pre-term birth (RR 1.38, 95% CI 1.09-1.75) and low birthweight (RR 1.45, 95% CI 1.10-1.92), but not with gestational hypertension (RR 1.09, 95% CI 0.91-1.31), gestational diabetes (RR 1.02, 95% CI 0.77-1.36) and SGA (RR 0.96, 95% CI 0.75-1.21). Associations with pre-eclampsia were strongest for discontinuation 0-3 months pre-pregnancy, for OCs containing ≥30 µg oestrogen and for first- or second-generation OCs. Pre-term birth and low birthweight were more likely to occur when OCs were discontinued 0-3 months pre-pregnancy, when using OCs containing <30 µg oestrogen and when using third-generation OCs. Associations with SGA were observed for OCs containing <30 µg oestrogen and for third- or fourth-generation OCs.

CONCLUSIONS

Periconceptional OC use, particularly those containing oestrogen, was associated with increased risks of pre-eclampsia, pre-term birth, low birthweight and SGA.

The gestational age-specific difference in birthweight between singletons born after fresh and frozen embryo transfer: A cohort study

INTRODUCTION

Accumulating studies have suggested singletons born after frozen embryo transfer (FET) were higher than those born after fresh embryo transfer (Fre-ET). However, fewer studies had investigated the gestational age-specific between-group difference in birthweight. This study aimed to investigate the gestational week-specific difference in singleton birthweight after FET vs Fre-ET and explore potential factors that impact the difference.

MATERIAL AND METHODS

In this retrospective cohort study, a total of 25 863 singletons were included. Multivariable linear regression and logistic regression were used to evaluate the between-group differences in mean birthweight and the incidences of large for gestational age (LGA) and small for gestational age (SGA), respectively.

RESULTS

Multivariable regression analyses showed a statistically significant interaction between types of embryo transfer (ie FET vs Fre-ET) and the gestational week on mean birthweight (P < 0.001) and on the risks of large for gestational age (P = 0.001) and small for gestational age (P < 0.001). When stratified by gestational week, the differences in mean birthweight and the risks of LGA and SGA were only observed in singletons born at 37 gestational weeks or later. After adjusting for confounders, full-term but not preterm singletons born after FET had a higher birthweight (3497.58 ± 439.73 g vs 3445.67 ± 450.24 g; adjusted mean difference 58.35 g; 95% confidence interval [CI] 38.72-77.98 g), a higher risk of LGA (24.3% vs 21.1%; adjusted odds ratio [OR] 1.28, 95% CI 1.15-1.42) and a lower risk of SGA (3.1% vs 4.8%; adjusted OR 0.61, 95% CI 0.53-0.70) compared with those born after Fre-ET.

CONCLUSIONS

The differences in birthweight between FET and Fre-ET were observed in full-term singletons but not preterm singletons.

High birth weight and greater gestational age at birth in singletons born after frozen compared to fresh embryo transfer

OBJECTIVE

While many studies agree that the fetal birth weight is higher after frozen embryo transfer (FET), few studies have explored the difference in fetal weight change during such pregnancies. This cohort study was to identify the difference in fetal birth weight and gestational age at birth between singletons born following fresh ET and those born following FET.

MATERIALS AND METHODS

This was a hospital-based cohort study using clinical data from the Kaohsiung Chang Gung Memorial Hospital Obstetric and Neonatal Database from January 1, 2007, to December 1, 2018. A sample of 784 eligible women who had singleton pregnancies and live-born deliveries after 428 fresh ET or 356 FET between January 2007 and December 2018.

RESULTS

Compared with those in the fresh ET group, singletons in the FET group had higher birth weight (3137 g [2880-3441 g] vs. 3060 g [2710-3340 g], p < 0.05), were born later (39.0 weeks of gestation [38.0-40.0 weeks] vs. 38.0 weeks of gestation [37.0-39.0 weeks], p < 0.05), and had a lower incidence of preterm birth (10.4% vs. 15.2%, p < 0.05). The difference in birth weight was not associated with maternal body weight (BW) or body mass index, increase in maternal BW in the third trimester, but related to the total increase in maternal BW during pregnancy.

CONCLUSIONS

The birthweight of singletons born following FET and fresh ET became significant in the late third trimester. The main reason is that singletons conceived from FET were at a lower relative risk of preterm delivery and had a higher gestational age at birth.

Adverse effect of assisted reproductive technology-related hyperoestrogensim on the secretion and absorption of uterine fluid in superovulating mice during the peri-implantation period

OBJECTIVES

This study aimed to investigate the potential mechanism of hyperoestrogensim elicited by ovulation induction affects endometrial receptivity and leads to embryo implantation abnormality or failure.

STUDY DESIGN

Establishment of ovulation induction mouse model. Changes in mouse body weight, ovarian weight, serum E2 level and oestrous cycle were observed. During the peri-implantation period, morphological changes in the mouse uterus and implantation sites and the localization and protein levels of oestrogen receptors ERα and ERβ, the tight junction factors CLDN3 and OCLN, the aquaporins AQP3, AQP4 and AQP8, and the sodium channel proteins SCNN1α, SCNN1β and SCNN1γ were observed. The expression and cellular localization of ERα, CLDN3, AQP8 and SCNN1 β in RL95-2 cell line were also detected by western blotting and immunofluorescence.

RESULTS

Ovarian and body weights were significantly higher in the 5 IU and 10 IU groups than in the CON group. The E2 level was significantly higher in the 10 IU group than in the CON group. The mice in the 10 IU group had a disordered oestrous cycle and were in oestrus for a long time. At 5.5 dpc, significantly fewer implantation sites were observed in the 10 IU group than in the CON (p<0.001) and 5 IU (p<0.05) groups. The probability of abnormal implantation and abortion was higher in the 10 IU group than in the CON and 5 IU groups. CLDN3, OCLN, AQP8 and SCNN1β in the mouse endometrium were localized on the luminal epithelium and glandular epithelium and expression levels were lower in the 10 IU group than in the CON group. The protein expression level of ERα was increased by 50% in the 10 IU group compared to the CON group. The expressions of CLDN3, AQP8, SCNN1β in RL95-2 cell line were significantly depressed by the superphysiological E2, ERα agonist or ERβ agonist, which could be reversed by the oestrogen receptor antagonist.

CONCLUSION

ART-induced hyperoestrogenism reduces CLDN3, AQP8 and SCNN1β expression through ERα, thereby destroying tight junctions and water and sodium channels in the endometrial cavity epithelium, which may cause abnormal implantation due to abnormal uterine fluid secretion and absorption.

Effect of a High Estrogen Level in Early Pregnancy on the Development and Behavior of Marmoset Offspring

The use of assisted reproductive technology (ART) has risen steadily worldwide over the past 3 decades and helps many infertile families. However, ART treatments lead to an abnormal internal environment in the uterus, which may increase the risks of health problems for the offspring. Higher maternal estradiol (E₂) is a notable feature in women who use ART treatments, and this has been suggested as a key factor for the risk of diseases in the offspring. In the current study, we have established a marmoset model with a high E₂ level in early pregnancy to examine its potential risk to the development and behavior of the offspring. In comparison with the normal group, babies of the high E₂ group exhibited lower average survival rates and birth weights. However, those who survived in the high E₂ group demonstrated normal vocal production with rich call repertoires, normal speed during locomotion, and normal behaviors in the home cage. In contrast to the normal group, surviving babies of the high E₂ group spent more time sleeping during development without signs of sleep disorders. In summary, our study revealed that high estrogen in early pregnancy may cause low survival rates and birth weights of the offspring, though the surviving infants did not show obvious behavioral deficiencies during development. The current study is a valuable and highly important non-human primate study for evaluating the safety of ART treatments. However, it is worth noting that some results did not reach the significant level, which may be due to the small sample size caused by animal shortage stemming from the COVID-19 epidemic.

Validation of Non-invasive Measurement of Cardiac Output: Using Whole-Body Bio-impedance Versus Inert Gas Rebreathing in Healthy Women Undergoing In Vitro Fertilisation

Background

Haemodynamic assessment in and before pregnancy is becoming increasingly important in relation to pregnancy complications and outcomes. Different methodologies exist but there is no gold-standard technique for non-invasive measurement of cardiac output (CO). We sought to assess two methods of CO measurement in healthy women undergoing in vitro fertilisation cycles (IVF). This was a prospective longitudinal study of 71 women aged 18–44 years planning IVF undergoing CO measurements obtained via inert gas rebreathing (IGR) using Innocor™ and whole-body bio-impedance (WBI) using Nicas™ to assess the reproducibility between the methods. Four visits occurred at which both techniques were used: initial assessment, embryo transfer, day of pregnancy test and 4 weeks post-transfer (regardless of whether conception occurred). Cross-sectional agreement of the methods was assessed using the calculation of bias, percentage error and limits of agreement (LOA) via the Bland–Altman analysis. Longitudinal agreement of the methods was assessed using a 4-quadrant plot with concordance rate, angular bias and radial limits of agreement (%).

Results

One hundred and thirteen measurements from 44 participants were suitable for cross-sectional (Bland–Altman) analysis. IGR (Innocor™) Mean CO was 4.61 L/min and 5.05 L/min with WBI (Nicas™). The bias was 0.44 L/min. The percentage error was 76% and intra-correlation coefficient was 0.135 (95% CI −0.43–0.306). Fifty-nine measurements from 28 participants were suitable for longitudinal (4Q-plot) analysis. The concordance rate was 64.4%, angular bias – 0.14, and radial limits of agreement + − 13.25°.

Conclusion

There was poor cross-sectional and longitudinal agreement between inert gas rebreathing and whole-body bio-impedance techniques. These techniques cannot be used interchangeably when measuring CO in women undergoing IVF, and these results may be more generalizable, to women in the peri-conception period.

Forskolin Induces Endocrine Disturbance in Human JEG-3 Placental Cells

Forskolin, used in folk medicine since ancient times, is now available as a dietary supplement, with an indication as a fat burner and appetite suppressant. However, the safety of forskolin is poorly documented especially for pregnant women. The question that we raised is what about the safety of forskolin in pregnant women? As the placenta, an endocrine organ, is the key organ of pregnancy, we evaluated the in vitro placental toxicity of forskolin. We focused first on the activation of a P2X7 degenerative receptor as a key biomarker for placental toxicity, and second on steroid and peptide hormonal secretion. We observed that forskolin activated P2X7 receptors and disturbed estradiol, progesterone, hPL and hyperglycosylated hCG secretion in human placental JEG-Tox cells. To the best of our knowledge, we highlighted, for the first time, that forskolin induced endocrine disturbance in placental cells. Forskolin does not appear to be a safe product for pregnant women and restrictions should be taken.

Characteristics of fetal physiological and pathological uterine effusion observed on prenatal ultrasonography: a case report

Background

The prenatal detection rate of fetal uterine effusion is very low, and current case reports mainly focus on pathological hydrometrocolpos. We presented two cases of fetal physiological uterine effusion with different ultrasonic characteristics and compared them with one case of hydrometrocolpos with the hope of identifying strategies to reduce misdiagnosis of fetal uterine effusion.

Case presentation

This paper reports the cases of two female fetuses with abnormal pelvic echoes in the third trimester, referred to a tertiary center to be screened for suspected pelvic teratoma and cystic mass, respectively. Ultrasound consultation revealed fetal uterine effusion. The two fetuses were delivered at our hospital after a full term. Re-examining the uterus and adnexa of the neonates revealed that the uterine effusion had subsided naturally. Another female fetus had a large cystic mass in the pelvic cavity in the third trimester, and prenatal examination indicated fetal hydrometrocolpos. The fetus was delivered at our hospital after a full term. The hydrometrocolpos existed even after birth. After consultation with a neonatal surgeon and gynecologist, the newborn was diagnosed with congenital imperforate hymen with hydrometrocolpos. Hymen puncture and open drainage led to a good prognosis.

Conclusions

Prenatal ultrasonography plays an important role in diagnosing and differentiating between physiological and pathological fetal uterine effusion. It can help reduce misdiagnoses that can lead to incorrect clinical decisions.

Environmental epigenetic interaction of gametes and early embryos

In recent years, the developmental origins of diseases have been increasingly recognized and accepted. As such, it has been suggested that most adulthood chronic diseases such as diabetes, obesity, cardiovascular disease, and even tumors may develop at a very early stage. In addition to intrauterine environmental exposure, germ cells carry an important inheritance role as the primary link between the two generations. Adverse external influences during differentiation and development can cause damage to germ cells, which may then increase the risk of chronic disease development later in life. Here, we further elucidate and clarify the concept of gamete and embryo origins of adult diseases by focusing on the environmental insults on germ cells, from differentiation to maturation and fertilization.

Comparative study on risk of birth defects in singleton ART birth under high levels of estrogen after fresh embryo transfer and frozen embryo transfer

OBJECTIVE

To investigate whether high estrogen (E2) levels caused by controlled ovarian hyperstimulation affect the birth defect rate in singleton assisted reproductive technology (ART) birth after conceived by fresh embryo transfer and frozen embryo transfer (FET).

METHODS

This was a retrospective cohort study. A total of 581 women with singletons, as well as those who have become pregnant and have had an unwanted abortion under high E2 levels on trigger day were divided into three groups. Group A received FET and the E2 levels on trigger day were higher than 5000 pg/ml. Group B received fresh embryo transfer and the E2 levels were between 3000 and 5000 pg/ml. Group C received FET and the E2 levels were between 3000 and 5000 pg/ml.

RESULTS

There were no significant differences in birth weight, delivery mode, preterm birth rate, and fetal sex between the three groups (p > .05). Birth defect rate in Group B was higher than that in Group A and C, and the rate between Group B and C had significant differences (p < .05). After adjusting for maternal age, BMI, and type of infertility, only a FET cycle is significantly associated with decreased birth defect rate.

CONCLUSION

Fresh embryo transfer under supraphysiological level of estrogen exposure may increase the birth defect rate of ART singletons. Even after prenatal screening and diagnosis, a part of birth defect could not be detected during pregnancy. When the estrogen levels on trigger day were no lower than 3000 pg/ml, FET should be advocated to reduce the occurrence of such risk.

The sex-specific difference in singleton birth weight after frozen embryo transfer compared with fresh embryo transfer: a secondary analysis of 3 randomized trials

OBJECTIVE

To assess whether the between-group difference in singleton birth weight following frozen vs. fresh embryo transfer varied with infant sex.

DESIGN

A post hoc exploratory secondary analysis of data from three multicenter randomized trials compared the live birth rates between freeze-only vs. fresh embryo transfer.

SETTING

Academic fertility centers.

PATIENT(S)

A total of 1,886 women who achieved singleton live birth after a frozen or fresh embryo transfer during these trials were included.

INTERVENTION(S)

Women underwent either a frozen or fresh embryo transfer.

MAIN OUTCOME MEASURE(S)

Mean birth weight, large for gestational age (LGA), and small for gestational age (SGA).

RESULT(S)

There was an interaction between the types of embryo transfer and infant sex on the birth weight and on the incidences of LGA and SGA. Among male infants, compared with singletons following fresh embryo transfer, singletons following frozen embryo transfer had higher mean birth weights (3,520.6 ± 526.1 vs. 3,345.1 ± 524.9 g), a higher risk of being LGA (25.2% vs. 15.7%), and a lower risk of being SGA (3.3% vs. 6.1%). However, among the female infants, no statistically significant difference was found in the mean birth weight (3,336.5 ± 514.8 vs. 3,299.5 ± 485.0 g) or the risks of being LGA (18.8% vs. 15.7%) or SGA (5.2% vs. 6.0%) between frozen and fresh embryo transfer.

CONCLUSION(S)

Male singletons born after frozen embryo transfer were more likely to have a higher birth weight than those born after fresh embryo transfer.

Elevated Expression of lncRNA MEG3 Induces Endothelial Dysfunction on HUVECs of IVF Born Offspring via Epigenetic Regulation

Cardiovascular dysfunction in children born after in vitro fertilization (IVF) has been of great concern, the potential molecular mechanisms for such long-term outcomes are still unknown. Here, we found that systolic blood pressure was a little higher in IVF born offspring at 2 years old compared to those born after being naturally conceived. Besides, the expression level of maternally expressed gene 3 (MEG3) was higher in human umbilical vein endothelial cells (HUVECs) from IVF offspring than that in spontaneously born offspring. Pearson correlation test showed that MEG3 relative expression is significantly related to the children's blood pressure (Coefficient = 0.429, P = 0.0262). Furthermore, we found decreased expression of endothelial nitric oxide synthase (eNOS) and vascular endothelial growth factor (VEGF) along with elevated expression of endothelial-1(ET1) in HUVECs from IVF offspring, accompanied by lower secretion of nitrite, VEGF, and higher secretion of ET1 in the umbilical cord serum of IVF offspring. Correlation analysis showed MEG3 expression highly correlated with ET1 and Nitrate concentration. With pyrosequencing technology, we found that elevated expression of MEG3 was the result of hypomethylation of the MEG3 promoter. Therefore, our results provide a potential mechanism addressing the high-risk of hypertension in IVF offspring via MEG3 epigenetic regulation.

High Maternal Serum Estradiol in First Trimester of Multiple Pregnancy Contributes to Small for Gestational Age via DNMT1-Mediated CDKN1C Upregulation

High maternal serum estradiol (E₂) levels in the first trimester of pregnancy are associated with a high incidence of low birth weight (LBW) and small for gestational age (SGA). This study aimed to investigate the effect of first-trimester high maternal serum E₂ levels on fetal growth and the underlying mechanisms in multiple pregnancies. Maternal serum E₂ levels of women at 8 weeks of gestation were measured. The expression levels of imprinted genes and DNMT1 were determined by RT-qPCR, and KvDMR1 methylation in embryo tissue, placenta, and newborn cord blood samples was examined by bisulfite sequencing PCR. The effect of E₂ on CDKN1C expression was investigated in HTR8 cells. The incidence of SGA was significantly higher in multiple pregnancies reduced to singleton than that in primary singleton pregnancies (11.4% vs. 2.9%) (P < 0.01) and multiple pregnancies reduced to twins than primary twins (38.5% vs. 27.3%) (P < 0.01). The maternal serum E₂ level at 8 weeks of gestation increased with the number of fetuses and was negatively correlated with offspring birth weight. CDKN1C and DNMT1 expression was significantly upregulated in embryo tissue, placenta, and cord blood from multiple pregnancies. Furthermore, there was a positive correlation between CDKN1C mRNA expression and KvDMR1 methylation levels. In HTR8 cells, DNMT1 mediated the estrogen-induced upregulation of CDKN1C, which might contribute to SGA. To minimize the risks of LBW and SGA, our findings suggest that abnormally high maternal serum E₂ levels should be avoided during the first trimester of multiple pregnancies from assisted reproductive technology (ART).

Do live birth rate and obstetric outcomes vary between immediate and delayed embryo transfers following freeze-all cycles?

RESEARCH QUESTION

Do live birth rates (LBR), obstetric and perinatal outcomes vary between women who underwent frozen embryo transfer (ET) in the immediately subsequent menstrual cycle, and with those who underwent delayed frozen ET.

DESIGN

Retrospective cohort study (n = 198) consisting of 119 women who underwent immediate transfer within 30 days of oocyte retrieval (OR) and 79 women who underwent delayed transfer which was performed after >30 days following OR. Either flexible antagonist or flexible progestin-primed ovarian stimulation protocols were started after a baseline ultrasonography on the second or third day of menstrual cycle. Only freeze all cycles were included in the study and all transfers were with hormonal endometrial preparation. Main outcome measures were LBR, birth weight, gestational day at birth and pregnancy complications.

RESULTS

Peak estradiol level on trigger day (2746 vs 2081 pg/ml) and number of metaphase-two oocytes (13 vs 10) were significantly higher in the immediate transfer group. Clinical pregnancy rate per ET was similar between the groups (50.4% vs 44.3%). However, miscarriage rate per positive pregnancy was significantly higher (12.3% vs 31.1%) while LBR per ET was significantly lower (42.9% vs 26.6%) in the delayed transfer group. Median gestational age at delivery were 267.5 and 268 days in the immediate and delayed transfer groups. Median birthweight was significantly higher in the delayed transfer group (3520 vs 3195 g). Adjusted analyses also suggest similar LBR with immediate and delayed transfer.

CONCLUSION(S)

Frozen ET in the immediate menstrual cycle and delayed ET, after a freeze all strategy did not show significant difference in terms of LBR after adjustment. Obstetric and perinatal outcomes of frozen ET in the immediate menstrual cycle appear reassuring.

Evaluation of the relationship between serum estradiol levels on human chorionic gonadotropin administration day and intracytoplasmic sperm injection outcomes: A retrospective population-based study

Background

The correlation between high estradiol (E2) levels induced by controlled ovarian hyperstimulation (COH) and pregnancy is controversial.

Objective

To assess the effect of serum E2 levels on the day of human chorionic gonadotropin administration on the intracytoplasmic sperm injection (ICSI) outcome.

Materials and Methods

The current study included 551 participants who had undergone ICSI between May 2014 and May 2016. Based on E2 levels, the individuals aged < 37 yr (n = 502) and 37-42 yr (n = 49) were categorized into six and three groups, respectively. ICSI outcomes including the number of retrieved oocytes (NRO), number of embryos (NE), pregnancy rate, and abortion rate were analyzed in both groups.

Results

Among participants aged < 37 yr, the NRO and NE were 8.69 ± 3.82 and 5.24 ± 2.32, respectively and they had a significant correlation with the E2 level on human chorionic gonadotropin administration day (p < 0.001 for both). Among participants aged > 37 yr, NRO and NE were 5.18 ± 3.17 and 3.40 ± 2.23, respectively, and the NRO (p < 0.001), NE (p < 0.001), pregnancy rate (p < 0.001), abortion rate (p = 0.007), and the number of grade A and B embryos (p = 0.003) had a significant association with the E2 level.

Conclusion

COH is a costly procedure that may have negative effects on endometrial receptivity. Thus, in order to prevent these effects and also to reduce the costs of COH, we recommend gaining optimum number of oocytes rather than maximum number during the procedure.

Immediate versus delayed frozen embryo transfer in women following a failed IVF-ET attempt: a multicenter randomized controlled trial

BACKGROUND

The optimal time at which to perform a frozen-thawed embryo transfer (FET) following a failed in-vitro fertilization-embryo transfer (IVF-ET) attempt remains elusive to most reproductive experts. Physicians often delay the introduction of FET due to concerns related to potential residual effects of ovarian hyperstimulation which may interfere with the regular menstrual cycle. Moreover, given that most of the published studies on the topic are retrospective and have inconsistent findings, it is crucial to develop evidence-based randomized control guides for clinical practice. Therefore, this well-designed randomized controlled trial (RCT) was conducted to determine whether it is necessary to delay FET for at least one menstrual cycle after the failure of fresh embryo transfer.

METHODS

Infertile women eligible for IVF-ET were invited to participate in this multicenter, randomized, non-inferiority, parallel-group, unblinded, controlled trial at the academic fertility centers of four public hospitals in Chinese Mainland. Infertile women scheduled to receive their first FET cycle after a failed IVF-ET attempt were randomly assigned to either (a) the immediate FET group in which FET was performed in the first menstrual cycle following the failed IVF-ET cycle (n = 366) or (b) the delayed FET group in which FET was performed in the second or subsequent menstrual cycle following the failed IVF-ET cycle (n = 366). All FET cycles were performed during hormone replacement cycles for endometrial preparation. The primary outcome was the ongoing pregnancy, defined as a detectable fetal heart beat beyond twelve weeks of gestation. Secondary outcomes were other pregnancy-related outcomes, maternal and neonatal complications. Analysis was performed by both intention-to-treat and per-protocol principles.

RESULTS

A total of 646 FETs were completed. The frequency of moderate to severe depression and high stress level prior to FET in delayed FET group were significantly higher than that in immediate FET group (10.6% vs 6.1%, p = 0.039; 30.3% vs 22.4%, p = 0.022, respectively). Immediate FET resulted in a higher frequency of clinical pregnancy than did delayed FET (41.7% vs 34.1%), for a relative risk (RR) of 1.23 (95% confidence interval [CI], 1.00-1.50; p = 0.045). Women who underwent immediate FET also had a lower frequency of biochemical pregnancy loss (11.7% vs. 30.6%), with a RR of 0.28 (95% CI 0.23-0.63, p < 0.001), and a higher frequency of embryo implantation (25.2% vs. 20.2%), with a RR of 1.25 (95% CI 1.01-1.53; p = 0.038). Although the ongoing pregnancy and live birth rates did not differ significantly between the immediate FET and delayed FET groups (37.1% vs 30.3%, RR 1.22, 95% CI 0.99-1.52, p = 0.067; 36.5% vs 30.0%, RR 1.22, 95% CI 0.98-1.52, p = 0.079, respectively), a multivariate logistic regression analysis adjusted for potential confounders such as depression and stress levels revealed that the immediate FET group had a significantly higher ongoing pregnancy and live birth rates than the delayed FET group (odds ratio 0.68, 95% CI 0.47-0.99, p = 0.041; odds ratio 0.67, 95% CI 0.46-0.96, p = 0.031). The risks of maternal and neonatal complications were comparable between the two groups.

CONCLUSIONS

In women with a previous failed IVF-ET attempt, immediate FET resulted in higher ongoing pregnancy and live birth rates than delayed FET. These findings warrant caution in the indiscriminate application of a delayed FET strategy when apparent risk of high stress level is perceived.

TRIAL REGISTRATION

ChiCTR2000033313 .

Propylparaben concentrations in the urine of women and adverse effects on ovarian function in mice in vivo and ovarian cells in vitro

Female reproduction is precisely regulated by hormones, and the ovary is easily affected by environmental endocrine disruptors (EDCs), which are ubiquitous in industrialized societies. Parabens are EDCs that are used as antibacterial preservatives in cosmetics, personal care products (PCPs), medicines, and food. We used ultrahigh-performance liquid chromatography-mass spectrometry to quantitatively detect methyl-, ethyl-, butyl-, and propylparaben (PP) concentrations in urine samples from 74 women of childbearing age. Balb/c mice were subcutaneously injected with 100 mg/kg/day of PP for 21 consecutive days or 100 or 1,000 mg/kg/day of PP during superovulation. Various concentrations of PP (ranging from 1 to 1,000 nM) were added to a human ovarian granulosa tumor-derived cell line (KGN) culture for 24 h. The urinary paraben concentrations of women who used cosmetics and other PCPs within 48 h prior to sample collection were significantly elevated, and the PP concentration was significantly positively correlated with the basal estradiol concentration. After PP injection, the mouse serum estradiol concentrations were significantly increased, estrus cycles were disordered, corpus luteum number was reduced, and number of oocytes retrieved was significantly reduced. In in vitro experiments, PP treatment increased estradiol synthesis and the expression levels of aromatase enzyme (CYP19A1) and steroidogenic acute regulatory protein. This study demonstrates the adverse effects of PP on ovarian estradiol secretion and ovulation, further evaluates the safety of PP as a preservative, and provides guidance for the use of PCPs and cosmetics by women of childbearing age.

Comparison of Genome-Wide DNA Methylation Profiles of Human Fetal Tissues Conceived by in vitro Fertilization and Natural Conception

Background

Assisted reproductive technology (ART) might induce adverse pregnancy outcomes and increase the risk of metabolic diseases in offspring' later life with unknown reasons. Here we evaluated the global methylation level and methylation profile of fetal tissue from elective terminations of pregnancy (ETP) after natural conception and multifetal pregnancy reduction (MFPR) after in vitro fertilization and embryo transfer (IVF-ET).

Results

Global methylation levels were comparable between the fetal tissue of ETP after natural conception group and MFPR after IVF-ET group. The methylation levels were lower in the hypermethylated regions of the MFPR group than in the ETP group, while the methylation levels were higher in the hypomethylated regions of the MFPR group. Heatmap visualization and hierarchical clustering of the candidate differentially methylated regions (DMRs) showed differences between the DMRs in the ETP and MFPR samples. We identified 196 differentially methylated regions that matched 164 genes between the ETP and MFPR groups. In the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses, skeletal system morphogenesis and diabetes mellitus ranked first. Ingenuity Pathway Analysis (IPA) revealed 8 diseases and functional annotations associated with IVT-ET. In the MFPR group, the final validation showed lower methylation levels in gene bodies of bone morphogenetic protein 4 (BMP4), higher methylation levels in the 1st exon and 5'UTR of thyroid peroxidase (TPO), and higher methylation levels in TSS1500 and TSS200 of interleukin 1 beta (IL1B).

Conclusions

ART does not alter global DNA methylation level, but influences DNA methylation variation in specific regions of human fetus in the early stage of life. Further studies are warranted to clarify the potential role of DNA methylation alterations in the gene expression profile.

Rare case of obstetric cholestasis presenting in the first trimester following in vitro fertilisation

Intrahepatic cholestasis of pregnancy (ICP) generally presents in the third trimester with pruritus without a rash, characterised by elevated bile acids, with or without transaminitis and hyperbilirubinaemia. Risk factors include a family history of cholestasis, South Asian ethnicity, multifetal gestation, in vitro fertilisation (IVF) and history of hepatitis or biliary disorders.IVF involves the use of high dose gonadotropin stimulation and human chorionic gonadotropin trigger. High doses of progesterone supplementation are additionally given after embryo transfer. The increase in oestrogen and progesterone levels early on in the pregnancy is a possible explanation for the development of ICP in IVF pregnancies at earlier gestations.We present a rare case of iatrogenic ICP presenting in the first trimester in a pregnancy conceived by IVF. Unlike other cases reported, our patient did not have recurrence of ICP in the third trimester, and also had no history of ICP in her first pregnancy.

Neurogenesis Potential Evaluation and Transcriptome Analysis of Fetal Hypothalamic Neural Stem/Progenitor Cells With Prenatal High Estradiol Exposure

High maternal estradiol is reported to induce metabolic disorders by modulating hypothalamic gene expression in offspring. Since neurogenesis plays a crucial role during hypothalamus development, we explored whether prenatal high estradiol exposure (HE) affects proliferation and differentiation of fetal hypothalamic neural stem/progenitor cells (NSC/NPCs) in mice and performed RNA sequencing to identify the critical genes involved. NSC/NPCs in HE mice presented attenuated cell proliferation but increased neuronal differentiation in vitro compared with control (NC) cells. Gene set enrichment analysis of mRNA profiles indicated that genes downregulated in HE NSC/NPCs were enriched in neurogenesis-related Gene Ontology (GO) terms, while genes upregulated in HE NSC/NPCs were enriched in response to estradiol. Protein-protein interaction analysis of genes with core enrichment in GO terms of neurogenesis and response to estradiol identified 10 Hub mRNAs, among which three were potentially correlated with six differentially expressed (DE) lncRNAs based on lncRNA profiling and co-expression analysis. These findings offer important insights into developmental modifications in hypothalamic NSC/NPCs and may provide new clues for further investigation on maternal environment programmed neural development disorders.

Effect of parental and ART treatment characteristics on perinatal outcomes

STUDY QUESTION

Do parental characteristics and treatment with ART affect perinatal outcomes in singleton pregnancies?

SUMMARY ANSWER

Both parental and ART treatment characteristics affect perinatal outcomes in singleton pregnancies.

WHAT IS KNOWN ALREADY

Previous studies have shown that singleton pregnancies resulting from ART are at risk of preterm birth. ART children are lighter at birth after correction for duration of gestation and at increased risk of congenital abnormalities compared to naturally conceived children. This association is confounded by parental characteristics that are also known to affect perinatal outcomes. It is unclear to which extent parental and ART treatment characteristics independently affect perinatal outcomes.

STUDY DESIGN, SIZE, DURATION

All IVF clinics in the Netherlands (n = 13) were requested to provide data on all ART treatment cycles (IVF, ICSI and frozen-thawed embryo transfers (FET)), performed between 1 January 2000, and 1 January 2011, which resulted in a pregnancy. Using probabilistic data-linkage, these data (n = 36 683) were linked to the Dutch Perinatal Registry (Perined), which includes all children born in the Netherlands in the same time period (n = 2 548 977).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Analyses were limited to singleton pregnancies that resulted from IVF, ICSI or FET cycles. Multivariable models for linear and logistic regression were fitted including parental characteristics as well as ART treatment characteristics. Analyses were performed separately for fresh cycles and for fresh and FET cycles combined. We assessed the impact on the following perinatal outcomes: birth weight, preterm birth below 37 or 32 weeks of gestation, congenital malformations and perinatal mortality.

MAIN RESULTS AND THE ROLE OF CHANCE

The perinatal outcomes of 31 184 out of the 36 683 ART treatment cycles leading to a pregnancy were retrieved through linkage with the Perined (85% linkage). Of those, 23 671 concerned singleton pregnancies resulting from IVF, ICSI or FET. Birth weight was independently associated with both parental and ART treatment characteristics. Characteristics associated with lower birth weight included maternal hypertensive disease, non-Dutch maternal ethnicity, nulliparity, increasing duration of subfertility, hCG for luteal phase support (compared to progesterone), shorter embryo culture duration, increasing number of oocytes retrieved and fresh embryo transfer. The parental characteristic with the greatest effect size on birth weight was maternal diabetes (adjusted difference 283 g, 95% CI 228-338). FET was the ART treatment characteristic with the greatest effect size on birth weight (adjusted difference 100 g, 95% CI 84-117) compared to fresh embryo transfer. Preterm birth was more common among mothers of South-Asian ethnicity. Preterm birth was less common among multiparous women and women with 'male factor' as treatment indication (compared to 'tubal factor').

LIMITATIONS, REASONS FOR CAUTION

Due to the retrospective nature of our study, we cannot prove causality. Further limitations of our study were the inability to adjust for mothers giving birth more than once in our dataset, missing values for several variables and limited information on parental lifestyle and general health.

WIDER IMPLICATIONS OF THE FINDINGS

Multiple parental and ART treatment characteristics affect perinatal outcomes, with birth weight being influenced by the widest range of factors. This highlights the importance of assessing both parental and ART treatment characteristics in studies that focus on the health of ART-offspring, with the purpose of modifying these factors where possible. Our results further support the hypothesis that the embryo is sensitive to its early environment.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by Foreest Medical School, Alkmaar, the Netherlands (grants: FIO 1307 and FIO 1505). B.W.M. reports grants from NHMRC and consultancy for ObsEva, Merck KGaA, iGenomics and Guerbet. F.B. reports research support grants from Merck Serono and personal fees from Merck Serono. A.C. reports travel support from Ferring BV. and Theramex BV. and personal fees from UpToDate (Hyperthecosis), all outside the remit of the current work. The remaining authors report no conflict of interests.

TRIAL REGISTRATION NUMBER

N/A.

Supraphysiological estradiol levels on the hCG trigger day are associated with SGA for singletons born from fresh embryo transfer

The effects of supraphysiological estradiol (E2) on neonatal outcomes and the significance of specific E2 concentrations remain unclear. The purpose of this study was to investigate whether supraphysiological E2 levels on the human chorionic gonadotropin (hCG) trigger day are associated with small size for gestational age (SGA) in singletons born from fresh embryo transfer (ET) cycles. Patients with singleton pregnancies who delivered after the transfer of fresh embryos, during the period from July 2012 to December 2017, at our center were included. We excluded cycles involving a vanishing twin, maternal age >35 years, basal follicle-stimulating hormone ≥10 mIU/ml, or anti-Müllerian hormone ≤1 ng/ml. We then divided all cycles into five groups by E2 level on trigger day: group A, <2000 pg/ml (reference group); group B, 2000 pg/ml≤E2<2999 pg/ml; group C, 3000 pg/ml≤E2<3999 pg/ml; group D, 4000 pg/ml≤E2<4999 pg/ml; and group E, ≥5000 pg/ml. The prevalence of SGA among singletons from fresh ET was the primary outcome. The SGA rate significantly increased when the E2 level was ≥4000 pg/ml, as observed by comparing groups D (odds ratio [OR]: 1·79, 95% confidence interval [CI]: 1·16-2·76, P = 0·01) and E (OR: 1·68, 95% CI: 1·10-2·56, P = 0·02) with the reference group. Multivariate logistic regression indicated that a serum E2 level of at least 4000 pg/ml on the hCG trigger day was associated with increased SGA and with significant differences for groups D (adjusted OR [AOR]: 1·65, 95% CI: 1·05-2·59, P = 0·03) and E (AOR: 1·60, 95% CI: 1·03-2·53, P = 0·04) relative to the reference group. In conclusion, in fresh ET cycles, the supraphysiological E2 ≥4000 pg/ml on the hCG trigger day increases the risk of SGA.

Further evidence that a supraphysiologic estradiol level during ovarian stimulation affects birthweight: findings of fresh and frozen embryo transfer with comparable estradiol levels on human chorionic gonadotropin trigger

Studies have reported a supraphysiologic estradiol (E2) level during ovarian stimulation may be related to low birthweight after fresh embryo transfer (ET), but whether a high E2 level in the stimulation cycle affects birthweight via frozen ET remained controversial. The study was to investigate whether a supraphysiologic E2 level in ovarian stimulation cycle affects birth weight in infants conceived via subsequent FET. In this retrospective cohort study, 2525 singletons conceived via FET and 2668 singletons conceived via fresh ET were analyzed. The birthweight and incidences of small for gestational age (SGA) in infants conceived via FET in groups with low and high levels of E2 did not differ significantly. Multivariate analyses showed that the peak E2 level was not predictive of SGA in infants conceived via FET. Singletons conceived via fresh ET had a higher risk of SGA than those conceived via FET even after comparable previous exposure to a high level of E2 > 3000 pg/mL. Our study results indicated that the increased risk of SGA was at least partly a result of the supraphysiologic E2 exposure to the intrauterine environment.

Perinatal outcomes of neonates born from different endometrial preparation protocols after frozen embryo transfer: a retrospective cohort study

BACKGROUND

Previous studies have focused on pregnancy outcomes after frozen embryo transfer (FET) performed using different endometrial preparation protocols. Few studies have evaluated the effect of endometrial preparation on pregnancy-related complications. This study was designed to explore the association between different endometrial preparation protocols and adverse obstetric and perinatal complications after FET.

METHODS

We retrospectively included all FET cycles (n = 12,950) in our hospital between 2010 and 2017, and categorized them into three groups, natural cycles (NC), hormone replacement therapy (HRT) and ovarian stimulation (OS) protocols. Pregnancy-related complications and subsequent neonatal outcomes were compared among groups.

RESULTS

Among all 12,950 FET cycles, the live birth rate was slightly lower for HRT cycles than for NC (HRT vs. NC: 28.15% vs. 31.16%, p < 0.001). The pregnancy loss rate was significantly higher in OS or HRT cycles than in NC (HRT vs. NC: 17.14% vs. 10.89%, p < 0.001; OS vs. NC: 16.44% vs. 10.89%, p = 0.001). Among 3864 women with live birth, preparing the endometrium using OS or HRT protocols increased the risk of preeclampsia, and intrahepatic cholestasis of pregnancy (ICP) in both singleton and multiple deliveries. Additionally, OS and HRT protocols increased the risk of low birth weight (LBW) and small for gestational age (SGA) in both singletons and multiples after FET.

CONCLUSION

Compared with HRT or OS protocols, preparing the endometrium with NC was associated with the decreased risk of pregnancy-related complications, as well as the decreased risk of LBW and SGA after FET.

A cohort study of dysmenorrhea and risk of low birth weight

OBJECTIVE

Little is known about the association between maternal history of dysmenorrhea and perinatal outcomes. The aim of this study was to investigate the association between maternal history of dysmenorrhea and low birth weight (LBW).

METHODS

A total of 6754 pregnant women were recruited from the ongoing prospective cohort study in Guangxi, China, in 2015-2018. Information on the maternal history of dysmenorrhea was obtained by questionnaires including visual analog scale (VAS) questions during the first antenatal care visit. The association of maternal history of dysmenorrhea and LBW was evaluated using logistic regression analyses adjusted for confounding factors (infant sex, maternal age, parity, pre-pregnancy body mass index (BMI) (kg/m²), gestational age, alcohol use during pregnancy, passive smoking, and occupational status).

RESULTS

Mothers with a history of dysmenorrhea were more likely to give birth to LBW infants (adjusted odds ratio (OR)=1.44; 95% confidence interval (CI): 1.12, 1.83). Among women with a history of dysmenorrhea, women ≥29 years old (adjusted OR 1.46; 95% CI 1.02, 2.10), multiparous (adjusted OR 1.59, 95% CI 1.12, 2.25), and women gave birth to female infant (adjusted OR = 1.53, 95% CI = 1.11, 2.11) had a higher risk of LBW.

CONCLUSIONS

As the first cohort study to investigate the association between maternal history of dysmenorrhea and LBW, our study shows that dysmenorrhea may increase the risk of LBW.

A systematic review of clinical efficacy of frozen-thawed embryos and fresh embryos in in-vitro fertilization cycles

BACKGROUND

Frozen-thawed embryo (FTE) and fresh embryo (FE) transfer are two common strategies in vitro fertilization (IVF), while the results and findings still vary among studies.

METHODS

We searched multiple databases for relevant studies comparing the clinical effects of FTE and FE. Meta-analyses were conducted with Review Manager 5.0 to assess the efficacy among included articles. We also analyzed the risk of bias for the reports.

RESULTS

Nine studies eventually met the inclusion criteria from 2010 to 2018, and 11396 patients were included. The meta-analyses indicated no significant difference in biochemical pregnancy, clinical pregnancy and ongoing pregnancy rates. Meanwhile, the implantation rate and live birth rate in frozen-thawed embryos were much higher than those of fresh embryo. The birth weight in the frozen-thawed ET group was greater than that of the FE group, and the low birth weight rate in FTE was lower than FE group.

CONCLUSION

Our findings suggested a trend toward favouring frozen-thawed FTE might be a preferred transfer strategy for patients with IVF.

Does the elevated estradiol level on the day of human chorionic gonadotropin administration affect embryo quality among women undergoing in vitro fertilization?

OBJECTIVE

To evaluate the association between estradiol (E2 ) levels on the day of human chorionic gonadotropin (hCG) administration and embryo quality during in vitro fertilization (IVF) cycles.

METHODS

A retrospective study of 6676 IVF cycles among women treated at the Reproductive Center of The First Affiliated Hospital of USTC, Hefei, China, from June 2014 to May 2017. E2 levels on hCG day were divided into four groups by 25th percentile: 0-1763 pg/mL (group I), 1763-3692 pg/mL (group II), 3692-4800 pg/mL (group III), and higher than 4800 pg/mL (group IV). Analysis of variance and multiple linear regression were used to test associations.

RESULTS

There were significant differences in the frequency of high-quality embryos between group I (51.6 ± 1.1%) and groups II (65.6 ± 0.8%), III (62.1 ± 0.7%), and IV (62.3 ± 0.7%). Using E2 as a dummy variable and group II as a control, multiple linear regression showed that E2 levels were associated with the frequency of high-quality embryos obtained (P < 0.05).

CONCLUSION

Serum E2 on hCG day had an impact on embryo quality. Higher E2 levels did not produce the most high-quality embryos; the highest frequencies were achieved for E2 levels within 1763-3692 pg/mL.

A Comparison of the Efficacy of Immediate Versus Delayed Frozen-Thawed Embryo Transfer on the Ongoing Pregnancy Rate After a Failed IVF Attempt: Study Protocol for a Randomized, Non-Inferiority, Parallel-Group, Controlled Trial

INTRODUCTION

In clinical practice, the ideal time at which to perform a Frozen-thawed Embryo Transfer (FET) after a failed In-vitro Fertilization-embryo Transfer (IVF-ET) is still unclear to most practicing physicians. In addition, physicians often delay the introduction of FET due to concerns on the possible residual effects of ovarian hyperstimulation, which may interfere with the regular menstrual cycle. Moreover, given that most of the published studies on the topic are retrospective with contradictory findings, it is crucial to provide evidence-based randomized control guides for clinical practice.

METHODS/ANALYSIS

The study is a randomized, non-inferiority, parallel-group, controlled trial that will enroll a total of 732 women undergoing their first FET after a failed fresh embryo transfer (ET) cycle. The participants will then be randomized into two groups based on a computer-generated randomized list. The two groups include: (i) an immediate group were FET will be carried out during the first menstrual cycle after a failed fresh ET cycle and (ii) a delayed group where FET will be carried out during the second menstrual cycle after a failed fresh ET cycle. Primary outcomes will be defined as viable pregnancies with fetal heartbeats, diagnosed through pelvic ultrasonography after twelve weeks of gestation.

ETHICS AND DISSEMINATION

The study was approved by the Ethics Committee of the Assisted Reproductive Medicine at the Affiliated Hospital of Shandong University of Traditional Chinese Medicine (SDTCM/E-2020.2.01). In addition, written informed consent will be obtained from all the participants before the study. The results of this trial will be disseminated in a peer-reviewed journal.

DISCUSSION

Currently, there is no consensus with regard to the duration after which the effects of ovarian stimulation are observed after a failed fresh ET and the optimal time required to begin FET. Moreover, no randomized controlled trial exists that compares the ongoing pregnancy rates after immediate versus delayed FET following a failed fresh ET cycle. Therefore, it is important to conduct a well-designed randomized trial to determine whether it is necessary to delay FET for at least one menstrual cycle after the failure of fresh ET.

CLINICAL TRIAL REGISTRATION

ChiCTR2000033313 (http://www.chictr.org.cn/enIndex.aspx).

Diminished verbal ability among children conceived through ART with exposure to high serum estradiol in utero

Purpose

Higher serum estradiol levels occur in women undergoing assisted reproductive technology (ART) owing to ovarian stimulation. Here, we investigated the association between maternal serum estradiol levels and the intellectual development of offspring conceived with ART.

Methods

A total of 204 singletons born after fresh embryo transfer were recruited for this cohort study. Among them, 102 children were born from mothers with high serum estradiol levels (> 12,000 pmol/L) on the day that human chorionic gonadotropin was administered. Another 102 children, matched by gestational age and age of the children, were recruited as controls from mothers with low serum estradiol (≤ 12,000 pmol/L). The Wechsler Preschool and Primary Scale of Intelligence was used to evaluate the intellectual development of the children.

Results

Children from mothers with higher serum estradiol levels scored lower in the verbal intelligence quotient (IQ) tests and verbal comprehension than children whose mothers had lower estradiol levels. The main difference between the two groups was in verbal subtests including information, vocabulary, and sorting. Partial correlation analysis revealed that the logarithm of maternal serum estradiol level negatively correlated with verbal IQ, performance IQ, and full scale IQ.

Conclusion

Our data demonstrate that a high maternal serum estradiol level may negatively associate the verbal ability of children conceived via ART.

Altered expression of DNA damage repair genes in the brain tissue of mice conceived by in vitro fertilization

Our previous study revealed a higher incidence of gene dynamic mutation in newborns conceived by IVF, highlighting that IVF may be disruptive to the DNA stability of IVF offspring. However, the underlying mechanisms remain unclear. The DNA damage repair system plays an essential role in gene dynamic mutation and neurodegenerative disease. To evaluate the long-term impact of IVF on DNA damage repair genes, we established an IVF mouse model and analyzed gene and protein expression levels of MSH2, MSH3, MSH6, MLH1, PMS2, OGG1, APEX1, XPA and RPA1 and also the amount of H2AX phosphorylation of serine 139 which is highly suggestive of DNA double-strand break (γH2AX expression level) in the brain tissue of IVF conceived mice and their DNA methylation status using quantitative real-time PCR, western blotting and pyrosequencing. Furthermore, we assessed the capacity of two specific non-physiological factors in IVF procedures during preimplantation development. The results demonstrated that the expression and methylation levels of some DNA damage repair genes in the brain tissue of IVF mice were significantly changed at 3 weeks, 10 weeks and 1.5 years of age, when compared with the in vivo control group. In support of mouse model findings, oxygen concentration of in vitro culture environment was shown to have the capacity to modulate gene expression and DNA methylation levels of some DNA damage repair genes. In summary, our study indicated that IVF could bring about long-term alterations of gene and protein expression and DNA methylation levels of some DNA damage repair genes in the brain tissue and these alterations might be resulted from the different oxygen concentration of culture environment, providing valuable perspectives to improve the safety and efficiency of IVF at early embryonic stage and also throughout different life stages.

In utero exposures to electronic-cigarette aerosols impair the Wnt signaling during mouse lung development

Currently, more than 9 million American adults, including women of childbearing age, use electronic-cigarettes (e-cigs). Further, the prevalence of maternal vaping now approaching 10% is similar to that of maternal smoking. Little, however, is known about the effects of fetal exposures to nicotine-rich e-cig aerosols on lung development. In this study, we assessed whether in utero exposures to e-cig aerosols compromised lung development in mice. A third-generation e-cig device was used to expose pregnant BALB/c mice by inhalation to 36 mg/mL of nicotine cinnamon-flavored e-cig aerosols for 14-31 days. This included exposures for either 12 days before mating plus during gestation (preconception groups) or only during gestation (prenatal groups). Respective control mice were exposed to filtered air. Subgroups of offspring were euthanized at birth or at 4 wk of age. Compared with respective air-exposed controls, both preconception and prenatal exposures to e-cig aerosols significantly decreased the offspring birth weight and body length. In the preconception group, 7 inflammation-related genes were downregulated, including 4 genes common to both dams and fetuses, denoting an e-cig immunosuppressive effect. Lung morphometry assessments of preconception e-cig-exposed offspring showed a significantly increased tissue fraction at birth. This result was supported by the downregulation of 75 lung genes involved in the Wnt signaling, which is essential to lung organogenesis. Thus, our data indicate that maternal vaping impairs pregnancy outcomes, alters fetal lung structure, and dysregulates the Wnt signaling. This study provides experimental evidence for future regulations of e-cig products for pregnant women and developmentally vulnerable populations.

Endometrial preparation for frozen-thawed embryo transfer in an artificial cycle: transdermal versus vaginal estrogen

The objective was to compare the endometrial thickness (ET) in a frozen embryo transfer (FET) cycle between transdermal and vaginal estrogen. Our secondary objectives were to compare the patient satisfaction and the pregnancy outcomes. Prospective monocentric cohort study between 01/2017 and 12/2017 at a single institution. Choice of administration was left to the patient. 119 cycles had transdermal estrogen (T-group) and 199 had vaginal estrogen (V-group). The ET at 10 ± 1 days of treatment was significantly higher in the T-group compared to the V-group (9.9 vs 9.3 mm, p = 0.03). In the T-group, the mean duration of treatment was shorter (13.6 vs 15.5 days, p < 0.001). The rate of cycle cancelation was comparable between the two groups (12.6% vs 8.5%, p = 0.24). Serum estradiol levels were significantly lower (268 vs 1332 pg/ml, p < 0.001), and serum LH levels were significantly higher (12.1 ± 16.5 vs 5 ± 7.5 mIU/ml, p < 0.001) in the T-group. Patient satisfaction was higher in the T-group (p = 0.04) and 85.7% (36/42) of women who had received both treatments preferred the transdermal over the vaginal route. Live birth rates were comparable between the two groups (18% vs 19%, p = 0.1). Transdermal estrogen in artificial FET cycles was associated with higher ET, shorter treatment duration and better tolerance.

Impact of Serum Estradiol Levels Prior to Progesterone Administration in Artificially Prepared Frozen Embryo Transfer Cycles

Background: The need for endocrine monitoring in artificial cycles for frozen embryo transfer (FET) remains unclear and, more specifically, the value of the late-proliferative phase serum estradiol (E2) levels is with conflicting evidence in current literature. Objective: To investigate whether artificial FET cycles require endocrine monitoring for the serum E2 level prior to initiation of exogenous progesterone administration after an endometrial thickness of 6.5 mm has been reached. Design: One thousand two hundred and twenty-two (n = 1,222) artificial FETs performed in a tertiary center between 2010 and 2015 were subdivided into 3 groups according to the following late-proliferative serum E2 level percentiles: ≤p10 (E2 ≤144 pg/ml; n = 124), p11-p90 (E2 from 145 to 438 pg/ml; n = 977) and >p90 (E2 >439 pg/ml; n = 121). A mixed-effects multilevel multivariable regression analysis was performed to assess the potential effect of the late-proliferative E2 level on the live birth rate (LBR). Results: The level of late-proliferative circulating E2 showed no significant difference in terms of LBR after FET. Specifically, the multivariable regression model demonstrated a LBR of 19.5% for the p11-p90 reference group, compared to 24.4% for the ≤p10 (p = 0.251) and 19.5% for the >p90 group (p = 0.989). Conclusion: In this large retrospective dataset, no association was observed between late-proliferative phase serum E2 levels and LBR following FET in artificially prepared cycles. Although, caution is warranted due to the retrospective nature of the analysis and the potential for unmeasured confounding, we argue that monitoring of the late-proliferative serum E2 levels and using them to guide clinical decision-making (e.g., medication step-up, cycle prolongation or cancelation) may be of questionable value.

Live birth rates and perinatal outcomes when all embryos are frozen compared with conventional fresh and frozen embryo transfer: a cohort study of 337,148 in vitro fertilisation cycles

BACKGROUND

It is not known whether segmentation of an in vitro fertilisation (IVF) cycle, with freezing of all embryos prior to transfer, increases the chance of a live birth after all embryos are transferred.

METHODS

In a prospective study of UK Human Fertilisation and Embryology Authority data, we investigated the impact of segmentation, compared with initial fresh embryo followed by frozen embryo transfers, on live birth rate and perinatal outcomes. We used generalised linear models to assess the effect of segmentation in the whole cohort, with additional analyses within women who had experienced both segmentation and non-segmentation. We compared rates of live birth, low birthweight (LBW < 2.5 kg), preterm birth (< 37 weeks), macrosomia (> 4 kg), small for gestational age (SGA < 10th centile), and large for gestational age (LGA > 90th centile) for a given ovarian stimulation cycle accounting for all embryo transfers.

RESULTS

We assessed 202,968 women undergoing 337,148 ovarian stimulation cycles and 399,896 embryo transfer procedures. Live birth rates were similar in unadjusted analyses for segmented and non-segmented cycles (rate ratio 1.05, 95% CI 1.02-1.08) but lower in segmented cycles when adjusted for age, cycle number, cause of infertility, and ovarian response (rate ratio 0.80, 95% CI 0.78-0.83). Segmented cycles were associated with increased risk of macrosomia (adjusted risk ratio 1.72, 95% CI 1.55-1.92) and LGA (1.51, 1.38-1.66) but lower risk of LBW (0.71, 0.65-0.78) and SGA (0.64, 0.56-0.72). With adjustment for blastocyst/cleavage-stage embryo transfer in those with data on this (329,621 cycles), results were not notably changed. Similar results were observed comparing segmented to non-segmented within 3261 women who had both and when analyses were repeated excluding multiple embryo cycles and multiple pregnancies. When analyses were restricted to women with a single embryo transfer, the transfer of a frozen-thawed embryo in a segmented cycles was no longer associated with a lower risk of LBW (0.97, 0.71-1.33) or SGA (0.84, 0.61-1.15), but the risk of macrosomia (1.74, 1.39-2.20) and LGA (1.49, 1.20-1.86) persisted. When the analyses for perinatal outcomes were further restricted to solely frozen embryo transfers, there was no strong statistical evidence for associations.

CONCLUSIONS

Widespread application of segmentation and freezing of all embryos to unselected patient populations may be associated with lower cumulative live birth rates and should be restricted to those with a clinical indication.

Oocyte exposure to supraphysiological estradiol during ovarian stimulation increased the risk of adverse perinatal outcomes after frozen-thawed embryo transfer: a retrospective cohort study

Maternal supraphysiological estradiol (E2) environment during pregnancy leads to adverse perinatal outcomes. However, the influence of oocyte exposure to high E2 levels on perinatal outcomes remains unknown. Thus, a retrospective cohort study was conducted to explore the effect of high E2 level induced by controlled ovarian stimulation (COH) on further outcomes after frozen embryo transfer (FET). The study included all FET cycles (n = 10,581) between 2014 and 2017. All cycles were categorized into three groups according to the E2 level on the day of the human Chorionic Gonadotropin trigger. Odds ratios (ORs) and their confidence intervals (CIs) were calculated to evaluate the association between E2 level during COH and pregnancy outcomes and subsequent neonatal outcomes. From our findings, higher E2 level was associated with lower percentage of chemical pregnancy, clinical pregnancy, ongoing pregnancy, and live birth as well as increased frequency of early miscarriage. Preterm births were more common among singletons in women with higher E2 level during COH (aOR1 = 1.93, 95% CI: 1.22-3.06; aOR2 = 2.05, 95% CI: 1.33-3.06). Incidence of small for gestational age (SGA) was more common in both singletons (aOR1 = 2.01, 95% CI: 1.30-3.11; aOR2 = 2.51, 95% CI: 1.69-3.74) and multiples (aOR1 = 1.58, 95% CI: 1.03-2.45; aOR2 = 1.99, 95% CI: 1.05-3.84) among women with relatively higher E2 level. No association was found between high E2 level during COH and the percentage of macrosomia or large for gestational age. In summary, oocyte exposure to high E2 level during COH should be brought to our attention, since the pregnancy rate decreasing and the risk of preterm birth and SGA increasing following FET.

Elevated Levels of Estradiol in Human Immunodeficiency Virus-Infected Pregnant Women on Protease Inhibitor-Based Regimens

Background

Human immunodeficiency virus (HIV)-infected pregnant women on protease inhibitor (PI)-based combination antiretroviral therapy (cART) have a greater risk for adverse birth outcomes, and an association with steroid hormone levels has been implicated. The objective of this study was to investigate the association between PI-cART and estradiol levels in pregnancy.

Methods

Fifty-five HIV-infected and 49 HIV-uninfected Canadian pregnant women were followed prospectively throughout gestation. All HIV-infected women were on a PI-based cART regimen. Maternal plasma samples were collected at 12-18 weeks, 24-28 weeks, 34-38 weeks, at delivery, and from the cord. Birth outcomes were recorded. Levels of estradiol, dehydroepiandrosterone sulfate (DHEAS), sex hormone-binding globulin (SHBG), cortisol, and adrenocorticotropic hormone (ACTH) were quantified by enzyme-linked immunosorbent assay.

Results

(median [interquartile range] for cord estradiol: 23.9 ng/mL [16.4-36.4] for HIV-infected exposed to PI-cART and 15.7 ng/mL [12.2-21.2] for HIV-negative; P = .0025). HIV-infected women had higher DHEAS levels in cord plasma that correlated with cord and maternal delivery estradiol levels. Cortisol and ACTH levels did not differ between groups. In the HIV-infected women, cord estradiol levels correlated negatively with birth weight centile (r = -0.47, P = .0016).

Conclusions

Our data suggest that PI-cART exposure in pregnancy is associated with elevated levels of estradiol, likely driven by higher fetal DHEAS production. Cord estradiol levels were inversely correlated with birth weight centile in infants born to PI-cART-exposed women, suggesting that fetal exposure to high estradiol levels may be contributing to cART-associated fetal growth restriction.

Estradiol Levels Are Altered in Human Immunodeficiency Virus-Infected Pregnant Women Randomized to Efavirenz-Versus Lopinavir/Ritonavir-Based Antiretroviral Therapy

Background

Combination antiretroviral therapy (cART) use in pregnancy has been associated with hormonal dysregulation. We performed a secondary retrospective analysis of longitudinal progesterone and estradiol levels in pregnancy using specimens from the Protease Inhibitors to Reduce Malaria Morbidity in HIV-infected Pregnant Women study, which randomized Ugandan human immunodeficiency virus (HIV)-infected ART-naive women to initiate either lopinavir/ritonavir (LPV/r)-based or efavirenz (EFV)-based cART.

Methods

Three hundred twenty-six women (160 randomized to the EFV arm and 166 women to the LPV/r arm) with at least 1 plasma sample collected during pregnancy were included. Enrollment samples collected prior to cART initiation were used as a cART-naive comparator group. Hormone levels were quantified by enzyme-linked immunosorbent assay.

Results

Estradiol levels were differentially affected by the 2 cART regimens. Exposure to LPV/r was associated with an increase in estradiol (P < .0001), whereas exposure to EFV was associated with a decrease in estradiol (P < .0001), relative to the cART-naive gestationally matched comparator group. Lower estradiol levels correlated with small for gestational age (SGA) (P = .0019) and low birth weight (P = .019) in the EFV arm, while higher estradiol levels correlated with SGA in the LPV/r arm (P = .027). Although progesterone levels were similar between treatment arms, we observed an association between SGA and lower progesterone in the LPV/r arm (P = .04). No association was observed between hormone levels and preterm birth in either arm. Levels of progesterone and estradiol were lower in cases of stillbirth, and levels of both hormones declined immediately prior to stillbirth in 5 of 8 cases.

Conclusions

Combination ART regimens differentially affect estradiol levels in pregnancy, a hormone critical to the maintenance of a healthy pregnancy. Identifying cART regimens that minimize perinatal HIV transmission without contributing to hormonal dysregulation represents an urgent public health priority.

Clinical Trials Registration

NCT00993031.

The greater incidence of small-for-gestational-age newborns after gonadotropin-stimulated in vitro fertilization with a supraphysiological estradiol level on ovulation trigger day

Introduction

Reproductive scientists have postulated various risk factors for lower birthweight following conventional gonadotropin‐stimulated in vitro fertilization compared with spontaneously conceived children: parental factors (age, health, duration of subfertility and smoking habits); ovarian stimulation; laboratory procedures; the number of oocytes retrieved and the number of embryos transferred. Our aim was to investigate the impact of gonadotropin stimulation and serum estradiol level on the risk of a newborn being small‐for‐gestational‐age.

Material and methods

We conducted a cohort study (2010‐2016) of singletons (n = 155) born either after conventional gonadotropin‐stimulated in vitro fertilization (using ≥150 IU/d human gonadotropin for stimulation) or after natural cycle in vitro fertilization without any stimulation. We analyzed perinatal outcomes using birthweight percentiles, adjusted for gestational age and sex.

Results

The proportion of small‐for‐gestational‐age was 11.8% following conventional gonadotropin‐stimulated in vitro fertilization and 2.9% after natural cycle in vitro fertilization (P = 0.058). The odds of small‐for‐gestational‐age were significantly higher with supraphysiological estradiol levels in maternal serum on ovulation trigger day (unadjusted odds ratio 4.58; 95% confidence interval 1.35‐15.55; P = 0.015). It remained significant after adjusting for maternal height, age and body mass index (adjusted odds ratio 3.83; 95% confidence interval 1.06‐13.82; P = 0.041).

Conclusions

We found an associated risk of children being born small‐for‐gestational‐age after conventional gonadotropin‐stimulated in vitro fertilization compared with natural cycle in vitro fertilization. This higher risk is significantly associated with supraphysiological estradiol levels. We propose a reduction in the dosage of gonadotropin to minimize the risk of small‐for‐gestational‐age and future health consequences.

Maternal estradiol and progesterone concentrations among singleton spontaneous pregnancies during the first trimester

BACKGROUND

Pregnancy hormonal milieu represents a crucial determinant of fetal outcome. We aim to determine 17β-estradiol (E₂) and progesterone (PGT) concentrations in spontaneous pregnancies during the first trimester. In addition, we aim to determine E₂ concentrations as a function of gestational age (GA) and PGT.

METHODS

Between November 2015 and March 2017, 104 healthy women of at least 18 years undergoing medical consultation for voluntary interruption of pregnancy were enrolled in an observational study at University Hospital ASST Fatebenefratelli Sacco, Milan, Italy. Only singleton pregnancies between 5⁺⁰ and 13⁺⁶ weeks of gestation were eligible. First trimester ultrasound scans were performed for dating and one fasting venous blood sample was collected for E₂ and PGT determinations.

RESULTS

E₂ and PGT concentrations steadily increased according to GA. The correlation between E₂ on a logarithmic scale and PGT concentrations was expressed by the following equation, explaining 12.6% of E₂ variance: logE₂ = 2.57 + 0.1 × PGT, (r = 0.34, p < 0.001). By performing a multivariable linear regression analysis adjusted for variables significantly correlated with E₂ concentrations, we obtained a model explaining the 53.5% of E₂ variance. The final equation to determine E₂ concentrations among Caucasian women was: logE₂ = 1.96 + 0.01 × GA + 0.004 × PGT.

CONCLUSIONS

Gestational week-specific reference intervals are reported for maternal E₂ and PGT concentrations during early pregnancy, further providing a model for E₂ assessment in this period. This will represent a starting point for further evaluations between twin and ART pregnancies, as well as to potentially improve pregnancy outcome and future health of the offspring.