The impact of ovarian stimulation for IVF on the developing embryo

Assessment of Repetitive Controlled Ovarian Stimulation (COS) Cycles on Oocyte Donors: Impact on Oocyte Quality and Viable Embryo Yield

The utilization of donor eggs has broadened the options for Assisted Reproductive Technology (ART) among women facing challenges with egg quantity or quality. Given that donors are typically selected from young and fertile individuals, In Vitro Fertilization with egg donation (IVF-ED) tends to exhibit higher rates of implantation, pregnancy, and live births compared to IVF with the woman's own eggs, especially for females over 35 years old. This has led to a projected increase in the demand for IVF-ED, surpassing the number of available donors. Consequently, many centers opt to use oocyte donors for multiple cycles. However, the correlation between repeated Controlled Ovarian Stimulation (COS) cycles and the performance of donors in terms of viable blastocyst stage embryo (VEC) or blastocyst embryo rate is not definitively established and remains of interest. This study aims to explore the preimplantation characteristics of embryo development and oocyte maturation status based on the number of donor COS cycles, employing a Generalized Linear Mixed Model (GLMM) framework. The study encompasses 1965 embryo transfer (ET) cycles involving 399 donors who underwent a minimum of two and a maximum of nine controlled ovarian hyperstimulation (COS) cycles. The findings indicate that, with the patient undergoing six or more cycles of ovarian stimulation, despite a 3.9% increase in both maturation and fertilization rates, there is a corresponding decrease of 4.5% in VEC rate and 4.7% in blastulation rates. In essence, an escalating number of donor COS cycles appears to be associated with a disadvantageous reduction in embryo quality.

Different doses of recombinant FSH and determining parameters of oxidative stress

Background

This study aimed to examine if there is a connection between recombinant FSH dose and OS parameters in serum and the impact on IVF outcome.

Methods

This study consisted of 101 participants that went through IVF procedures. Parameter that were tested are SOD, SH groups and MDA. Serum samples were drawn before stimulation and on the last day of ovarian stimulation.

Results

Two groups were formed according to the dose of gonadotropins (rFSH). In both groups there were no significant differences in live-birth rate and miscarriage. In both groups mean serum MDA and SH-groups were significantly higher after ovarian stimulation, but mean serum SOD was significantly lower when compared to values before stimulation. There were less patients without OS before stimulation.

Conclusions

Our results suggest that there is a difference in serum concentration in groups SOD, SH groups and MDA at the beginning and at the end ovarian stimulation. On the other hand, dose of rFSH is not related with change of parameters for oxidative stress, quality of oocytes, embryos, fertilization, pregnancies, and miscarriage rate. Patients without oxidative stress before the IVF procedure needed lower doses of gonadotropins during stimulation.

Exploring the Impact of Controlled Ovarian Stimulation and Non-Invasive Oocyte Assessment in ART Treatments

Invasive and noninvasive features are normally applied to select developmentally competent oocytes and embryos that can increase the take-home baby rates in assisted reproductive technology. The noninvasive approach mainly applied to determine oocyte and embryo competence has been, since the early days of IVF, the morphological evaluation of the mature cumulus-oocyte complex at the time of pickup, first polar body, zona pellucida thickness, perivitelline space and cytoplasm appearance. Morphological evaluation of oocyte quality is one of the options used to predict successful fertilization, early embryo development, uterine implantation and the capacity of an embryo to generate a healthy pregnancy to term. Thus, this paper aims to provide an analytical revision of the current literature relating to the correlation between ovarian stimulation procedures and oocyte/embryo quality. In detail, several aspects of oocyte quality such as morphological features, oocyte competence and its surrounding environment will be discussed. In addition, the main noninvasive features as well as novel approaches to biomechanical parameters of oocytes that might be correlated with the competence of embryos to produce a healthy pregnancy and live birth will be illustrated.

Effects of controlled ovarian stimulation regimens on top-quality blastocyst development and perinatal outcomes with the freeze-all strategy: A retrospective comparative study

OBJECTIVE

This study aimed to determine the effect of ovarian stimulation regimens on the top-quality blastocyst development rate and perinatal outcomes with the freeze-all strategy.

METHODS

A retrospective comparative cohort analysis of 149 in vitro fertilization (IVF) cycles using the freeze-all strategy was conducted. The IVF cycles were stimulated with either a gonadotropin-releasing hormone antagonist or clomiphene citrate along with gonadotropin based on the patient's serum anti-Müllerian hormone level. Oocyte retrieval, fertilization, and embryo culture were performed following standard procedures. All good-quality blastocysts were cryopreserved and used for frozen-thawed embryo transfer (FET) in subsequent cycles. The fertilization, blastulation, and top-quality blastocyst development rates were calculated. The perinatal outcomes of FET cycles, gestational period, and birth weight were assessed.

RESULTS

The main outcome of this study was the top-quality blastocyst development rate, and the secondary outcomes were perinatal parameters (e.g., gestational period and birth weight) between the stimulation regimens. Despite the higher number of usable-quality embryos in the antagonist group, the blastocyst development rate remained comparable (p=0.105). Similarly, perinatal outcomes were comparable in subsequent FET cycles (p=0.538).

CONCLUSION

These findings suggest that the choice between antagonist and clomiphene citrate with gonadotropin as stimulation in controlled ovarian stimulation regimens may not affect the top-quality blastocyst development rate. The IVF outcomes (e.g., clinical pregnancy, miscarriage, and live birth rates) remained unaffected in subsequent FET cycles. Unlike fresh embryo transfer, the birth weight and gestational length were not associated with prior controlled ovarian stimulation regimens when the freeze-all strategy was used.

Effect of Superovulation Treatment on Oocyte's DNA Methylation

Controlled ovarian stimulation is a necessary step in some assisted reproductive procedures allowing a higher collection of female gametes. However, consequences of this stimulation for the gamete or the offspring have been shown in several mammals. Most studies used comparisons between oocytes from different donors, which may contribute to different responses. In this work, we use the bovine model in which each animal serves as its own control. DNA methylation profiles were obtained by single-cell whole-genome bisulfite sequencing of oocytes from pre-ovulatory unstimulated follicles compared to oocytes from stimulated follicles. Results show that the global percentage of methylation was similar between groups, but the percentage of methylation was lower for non-stimulated oocytes in the imprinted genes APEG3, MEG3, and MEG9 and higher in TSSC4 when compared to stimulated oocytes. Differences were also found in CGI of imprinted genes: higher methylation was found among non-stimulated oocytes in MEST (PEG1), IGF2R, GNAS (SCG6), KvDMR1 ICR UMD, and IGF2. In another region around IGF2, the methylation percentage was lower for non-stimulated oocytes when compared to stimulated oocytes. Data drawn from this study might help to understand the molecular reasons for the appearance of certain syndromes in assisted reproductive technologies-derived offspring.

Left Ventricular Diastolic Function in Subjects Conceived through Assisted Reproductive Technologies

Subjects conceived through assisted reproductive technologies (ART) potentially suffer from impaired left ventricular (LV) function due to premature vascular aging. This study aimed to evaluate whether subtle differences in LV diastolic function can be observed echocardiographically between young ART subjects and their spontaneously conceived peers. The echocardiographic assessment included the measurement of LV dimensions, mitral inflow velocities, and myocardial velocity at early diastole (E', cm/s) at the LV wall and the interventricular septum (IVS). An average from E/E'LV and E/E'IVS (E/E'AVG) was derived. In total, 66 ART subjects and 83 controls (12.85 ± 5.80 years vs. 13.25 ± 5.89 years, p = 0.677) were included. The ART subjects demonstrated a significantly lower E'LV (19.29 ± 3.29 cm/s vs. 20.67 ± 3.78 cm/s, p = 0.020) compared to their spontaneously conceived peers. Study participants of ≥ 10 years of age displayed a significantly higher E/E'AVG (6.50 ± 0.97 vs. 6.05 ± 0.99, p = 0.035) within the ART cohort. The results of this study demonstrate a significantly lower LV diastolic function in the ART subjects. However, no significant changes in LV diastolic function were observed between the two groups when the results were adjusted for age, birth weight percentile, and gestational age. Those ART subjects born preterm might have an elevated risk of developing LV diastolic alterations and could therefore profit from close echocardiographic monitoring.

The effect of Bushen Culuan Decoction on anovulatory infertile women among 6 different diseases: a study protocol for a randomized, double-blinded, positively controlled, adaptive multicenter clinical trial

BACKGROUND

Anovulation is one of the main causes of female infertility. This study will evaluate the effectiveness and safety of Bushen Culuan Decoction for anovulatory infertility caused by six diseases, including anovulatory abnormal uterine bleeding, polycystic ovarian syndrome, hyperprolactinemia, luteinized unruptured follicle syndrome, corpus luteum insufficiency, and premature ovarian insufficiency.

METHODS

This is a randomized, double-blinded, double-dummy, parallel, positively controlled, adaptive, multicenter clinical trial. All participants will be randomly allocated by a central randomization system to the treatment group or the control group in a 1:1 ratio. The treatment group will undergo a 14-day treatment with Bushen Culuan Decoction 13 g three times a day and a 5-day treatment with clomiphene citrate placebo tablets 50 mg once a day starting on day 5 of every menstrual period. The control group will undergo a 14-day treatment with Bushen Culuan Decoction placebo 13 g three times a day and a 5-day treatment with clomiphene citrate tablets 50 mg once a day from day 5 in every menstrual period. The whole treatment will last through 3 menstrual periods or 6 menstrual periods, depending on whether ovulation is regained in the first 3 menstrual periods. All statistical analyses will be performed in SPSS 21.0 (SPSS, Chicago, Illinois, USA), and a p value < 0.05 will be considered statistically significant.

DISCUSSION

The objective of this RCT is to evaluate whether Bushen Culuan Decoction enables a higher pregnancy rate than clomiphene citrate in women with anovulatory infertility and to identify the anovulatory diseases for which Bushen Culuan Decoction has higher effectiveness .This study has been approved by the Medical Ethics Committee of Xiyuan Hospital China Academy of Chinese Medical Sciences (No. 2017XLA037-2). The results of this study will be offered for publication in peer-reviewed journals.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03709849 . Registered on 19 November 2018.

IGF2R, KCNQ1, PLAGL1, and SNRPN DNA methylation is completed in bovine by the early antral follicle stage

Imprinted genes are inherited with different DNA methylation patterns depending on the maternal or paternal origin of the allele. In cattle (Bos taurus), abnormal methylation of these genes is linked to the large offspring syndrome, a neonatal overgrowth phenotype analogous to the human Beckwith-Wiedemann syndrome. We hypothesized that in bovine oocytes, some of the methylation patterns on maternally imprinted genes are acquired in the last phase of folliculogenesis. The pyrosequencing analysis of IGF2R, KCNQ1, PLAGL1, and SNRPN imprinted genes showed no clear progression of methylation in oocytes from follicles 1-2 mm (late pre antral/early antral) and up. Instead, these oocytes displayed complete methylation at the imprinted differentially methylated regions (>80%). Other mechanisms related to imprint maintenance should be investigated to explain the hypomethylation at IGF2R, KCNQ1, PLAGL1, and SNRPN maternally imprinted sites observed in some bovine embryos.

Comparison of the Fetal Fraction of Cell-Free DNA in In-Vitro Fertilization (IVF) Versus Natural Conception Evaluation of the Fetal Fraction With IVF Parameters

Background

As the offspring of assisted reproduction techniques (ARTs) have become a substantial proportion of the population, increased attention has been placed on the safety of ART. Investigators have focused on identifying a tool that combines molecular or biological tests that can predict the outcomes of in-vitro fertilization (IVF) or intracytoplasmic sperm injection and the resulting pregnancy after ART-mediated embryo implantation. This study aimed to answer the following questions: is there a difference between natural conception and IVF pregnancies regarding fetal fraction (FF) of cell-free DNA (cfDNA) in maternal age, birth weight, gender, and gestational age? Is there a difference between FF concentration regarding the parameters of IVF as possible predictive factors affecting the outcomes of IVF?

Methodology

This study included 31 women with singleton pregnancies conceived via IVF who underwent cell-free fetal DNA (cffDNA) screening for trisomy 13, 18, and 21; sex determination; and FF. The control group included 55 women who experienced natural conception. For all women, anthropometric characteristics such as age, weight, height, and body mass index (BMI) were recorded. For the IVF group, early follicular phase values of follicle-stimulating hormone, luteinizing hormone, prolactin, anti-müllerian hormone, thyroid-stimulating hormone, and estradiol were recorded.

Results

The natural conception and IVF groups were similar regarding maternal age, BMI of the mother, gender, birth weight, and gestational age. FF was not significantly different between the natural conception and IVF groups (10 (3.8) vs. 9 (2.6); p = 0.144). The results were similar after adjusting for maternal age via regression analysis. cfDNA was not associated with maternal age, birth weight, gender, or gestational age in the entire study sample or separately for the natural conception and IVF groups. No significant correlation was found between cfDNA and IVF parameters.

Conclusions

The FF is an important factor for non-invasive prenatal testing (NIPT) accuracy. Several studies have found a reduction in FF in pregnancies following ART compared with natural conception, while other studies have presented no differences in the FF. All researchers agree on the importance of NIPT; however, knowledge on how the FF is affected in ART pregnancies compared with naturally conceived pregnancies is very limited. In this study, no difference in FF for the IVF group compared with natural conception women was observed. The cffDNA concentrations in maternal serum do not appear to be affected in IVF conception. We suggest that FF is an independent factor compared with IVF parameters.

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

STUDY QUESTION

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

SUMMARY ANSWER

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

WHAT IS KNOWN ALREADY

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

STUDY DESIGN, SIZE, DURATION

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

PARTICIPANTS/MATERIALS, SETTING, METHODS

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

MAIN RESULTS AND THE ROLE OF CHANCE

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

LIMITATIONS, REASONS FOR CAUTION

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

WIDER IMPLICATIONS OF THE FINDINGS

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

STUDY FUNDING/COMPETING INTEREST(S)

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

TRIAL REGISTRATION NUMBER

N/A.

Ovarian Stimulation in Assisted Reproductive Technology Cycles for Varied Patient Profiles: An Indian Perspective

Controlled ovarian stimulation has been an integral part of in vitro fertilisation (IVF) treatment cycles. Availability of different gonadotropins for ovarian stimulation and gonadotropin releasing hormone (GnRH) analogues for prevention of premature rise of leutinising hormone during follicular phase offer an opportunity to utilise them for a successful outcome in women with different subsets of ovarian response. Further, use of GnRH agonist as an alternative for human chorionic gonadotropin improves safety of ovarian stimulation in hyper-responders. Mild ovarian stimulation protocols have emerged as an alternative to conventional protocols in the recent years. Individualisation plays an important role in improving safety of IVF in hyper-responders while efforts continue to improve efficacy in poor responders. Some of the follicular and peri-ovulatory phase interventions may be associated with negative impact on the luteal phase and segmentalisation of the treatment with frozen embryo transfer may be an effective strategy in such a clinical scenario. This narrative review looks at the available evidence on various aspects of ovarian stimulation strategies and their consequences. In addition, it provides a concise summary of the evidence that has emerged from India on various aspects of ovarian stimulation.

Live birth after letrozole as an adjunct to follicle-stimulating hormone versus follicle-stimulating hormone alone for ovarian stimulation in in vitro fertilisation cycles-study protocol for a randomised controlled trial

INTRODUCTION

In vitro fertilisation (IVF) is an effective infertility treatment but the live birth rate remains unsatisfactory. Ovarian stimulation by follicle-stimulating hormone (FSH) is routinely used in IVF and the resulting high serum estradiol levels may impair oocyte/embryo quality and endometrial receptivity. Letrozole, an aromatase inhibitor, can reduce serum estradiol levels following ovarian stimulation. We aim to test the hypothesis that co-treatment with letrozole reduces supraphysiological serum estradiol levels and improves endometrial receptivity, leading to a higher live birth rate of IVF. We are conducting a randomised controlled trial (RCT) to evaluate whether letrozole as an adjunct to FSH in IVF is superior to FSH alone in the live birth rate of fresh embryo transfer.

METHODS/DESIGN

This is an open-label randomised controlled superiority trial being performed in two assisted reproduction centres in China. Infertile women who have antral follicle count (AFC) before ovarian stimulation or on day 5 of ovarian stimulation ≥15 are randomly allocated in a 1:1 ratio to receive either letrozole and FSH or FSH alone in a GnRH antagonist protocol. Recruited women follow the standard operating procedures of the two centres. The primary outcome is the live birth rate of the fresh embryo transfer. Stimulation parameters, maternal side effects and obstetric and perinatal complications are secondary outcomes. The planned sample size is 900, i.e. 450 per group.

DISCUSSION

The present study is the first multicentre randomised study to compare the live birth rate of the fresh embryo transfer following ovarian stimulation by letrozole and FSH versus FSH alone in women with anticipated high ovarian responses.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02912988 . Registered on September 23, 2016. This trial protocol is version 2.0.

Association of antimüllerian hormone with polycystic ovarian syndrome phenotypes and pregnancy outcomes of in vitro fertilization cycles with fresh embryo transfer

Objective

The current study was undertaken to investigate the relationship between antimüllerian hormone (AMH) and polycystic ovarian syndrome (PCOS) phenotypes and to determine whether AMH is associated with pregnancy outcomes in infertile women undergoing their first in vitro fertilization (IVF) treatment.

Methods

We performed a retrospective cohort study of 2973 infertile women, including 418 women with PCOS undergoing their first IVF treatment at a private fertility center from January 2014 to March 2018. Women were stratified into three groups using cutoffs defined by the 25^th and 75^th percentiles of the serum AMH level: 746 women had AMH ≤ 2.25 ng/mL; 1486 women had AMH between 2.25 to 5.71 ng/mL; and 741 women had AMH > 5.71 ng/mL. Endocrine characteristics, PCOS phenotypes, stimulation outcomes, pregnancy outcomes were compared among these groups. When there were any statistical differences (P < 0.05) among the three groups, Bonferroni test was performed as post-hoc tests to determine where the statistical differences existed. To assess the relationships between AMH and pregnancy outcomes in total patients and PCOS patients, logistic regression analysis, adjusted for potential confounding covariates, were performed.

Results

Women with high AMH had greater prevalence of hyperandrogenism (HA), polycystic ovarian morphology (PCOM) and amenorrhea than women with low or average AMH. The clinical pregnancy rate were significantly higher in the high-AMH group compared with low- and average-AMH groups (69.9% vs. 58.8% and 64.7% respectively; P < 0.001). The live birth rate was significantly lower in women with AMH ≤ 2.25 ng/mL compared with average- and high-AMH groups (47.6% vs. 55.2 and 59.5% respectively; P < 0.001). However, after controlling for maternal age, oocyte yield, as well as other confounders, AMH was no longer associated with a higher live birth rate (aOR 1.037, 95% CI 0.853–1.261, P = 0.717; aOR 1.099, 95% CI 0.858–1.408, P = 0.455, respectively) and clinical pregnancy rate (aOR 1.064, 95% CI 0.834–1.359, P = 0.617; aOR 1.181, 95% CI 0.875–1.595, P = 0.276, respectively). Moreover, pregnancy outcomes did not differ in PCOS women according to AMH quartiles.

Conclusion

Increased AMH levels associated with PCOS severity and greater ovarian stimulation. However, AMH was not associated with clinical pregnancy rate and live birth rate after controlling for other confounders in women undergoing IVF. Thus, AMH should not be used to alter clinical decisions and exclude patients based on a low or even undetectable AMH value.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04518-0.

Neonatal outcomes and congenital malformations in children born after progestin-primed ovarian stimulation protocol

PURPOSE

The purpose of this study is to assess the safety of progestin-primed ovarian stimulation (PPOS) protocol regarding the neonatal outcomes and congenital malformations in babies born after in vitro fertilization (IVF) and frozen embryo transfer (FET).

METHODS

In this large retrospective cohort study, a total of 16,493 infants born between 1 September 2013 and 31 July 2021 from IVF and FET cycles after treatment with either PPOS (n = 15,245) or gonadotropin-releasing hormone antagonist (GnRH-ant) (n = 1,248) were finally enrolled. The primary outcome measure was the incidence of congenital malformations. The secondary outcome measures were rates of low birth weight (LBW), very low birth weight (VLBW), preterm birth (PTB), very preterm birth (VPTB), and early neonatal death.

RESULTS

Birth characteristics for both singletons and twins regarding the sex of infants, gestational age, birth weight, and birth length were comparable between the PPOS group and the GnRH-ant group. Rates of LBW, VLBW, PTB, VPTB, and early neonatal death were also similar. The reanalysis using propensity score matching (PSM) and multivariable logistic regression indicated that the PPOS protocol could not increase the risk of adverse neonatal outcomes compared with the GnRH-ant protocol. Furthermore, no significant difference was observed in the overall incidence of congenital malformations in live-born babies. After PSM and controlling for all confounders, the results remained insignificant with an adjusted odds ratio of 0.66 [95% confidence interval (CI) 0.32-1.34] and 2.43 [95% CI 0.97-6.06], respectively, for singletons and twins.

CONCLUSIONS

Our study suggests that compared with GnRH-ant treatment for IVF, the PPOS protocol could not produce a negative effect on the newborn population in terms of neonatal outcomes and congenital malformations.

Associations Between Asthma and Polycystic Ovary Syndrome: Current Perspectives

A potential correlation between polycystic ovary syndrome (PCOS) and asthma, used to be identified as diseases originating from two independent systems, has been supported by increasing evidence. From an epidemiological perspective, mounting studies have confirmed that women suffering from PCOS exhibit increased susceptibility to asthma. Meanwhile, PCOS and asthma seem to share several mutual pathological conditions, such as metabolic disorders, hormonal fluctuation, proinflammatory state, etc. Here, we further elucidate the correlation between asthma and PCOS by focusing on the internal common pathophysiology and adverse influences on women's health. Understanding the internal connection between PCOS and asthma may shed light on developing new prevention and control strategies to fight against these conditions.

Effects of Repeated Ovarian Stimulation on Ovarian Function and Aging in Mice

Controlled ovarian hyperstimulation (COH) is routinely used in the in vitro fertilization and embryo transfer (IVF-ET) cycles to increase the number of retrieved mature oocytes. However, the relationship between repeated COH and ovarian function is still controversial. Therefore, we investigated whether repeated ovarian stimulation affects ovarian aging and function, including follicular development, autophagy, and apoptosis in follicles. Ovarian hyperstimulation in mice was induced by intraperitoneal injection with pregnant mare serum gonadotropin (PMSG) and human chorionic gonadotropin (hCG). Mice subjected to ovarian stimulation once were used as a control group and 10 times as an experimental group. Repeated injections with PMSG and hCG significantly reduced the number of primary follicles compared to a single injection. The number of secondary and antral follicles increased slightly, while the number of corpus luteum increased significantly with repeated injections. On the other hand, repeated injections did not affect apoptosis in follicles associated with follicular atresia. The expression of autophagy-related genes Atg5, Atg12, LC3B, and Beclin1, cell proliferation-related genes mTOR, apoptosis-related genes Fas, and FasL was not significantly different between the two groups. In addition, the expression of the aging-related genes Dnmt1, Dnmt3a, and AMH were also not significantly different. In this study, we demonstrated that repeated ovarian stimulation in mice affects follicular development, but not autophagy, apoptosis, aging in ovary. These results suggest that repetition of COH in the IVF-ET cycle may not result in ovarian aging, such as a decrease in ovarian reserve in adult women.

Function of Follicular Cytokines: Roles Played during Maturation, Development and Implantation of Embryo

A balance within the immune system is necessary for the proper development of ovarian follicles. Numerous cytokines were detected in follicular fluid, the role of which in reproductive physiology seems crucial. They influence the development and maturation of the follicle, ovulation, and corpus luteum formation, as well as embryo implantation and maintenance of pregnancy. The analysis of follicular fluid requires its collection by puncturing of the ovary, which is usually executed in connection with various gynaecological procedures. When interpreting such test results, clinical indications for a given procedure and the method of patient preparation should be taken into account. This review revealed the results of currently available studies on the concentration of pro-inflammatory cytokines in follicular fluid in various forms of infertility. Additionally, it presented cytokines, whose concentration has a significant impact on the size of ovarian follicles, their number, the effectiveness of in vitro fertilisation, development of the embryo, and chances of correct implantation. Despite the many recent publications, the knowledge of follicular fluid immunology in the context of reproductive pathology is superficial and further research is required to extensively understand the roles of individual cytokines in reproductive pathology. In the future, this knowledge may enable patients’ individual qualifications to individual methods of infertility treatment, as well as the possible adjustment of the treatment regimen to the patient’s immune profile.

Relationship between follicular size and developmental capacity of oocytes under controlled ovarian hyperstimulation in assisted reproductive technologies

PURPOSE

We investigate the relationships between oocyte developmental capacity and follicular size of its origin in Japanese women: those undergoing conventional IVF (cIVF) and ICSI, respectively.

METHODS

A total of 3377 follicles were punctured separately and were classified into three groups (large, medium, and small) by their diameters. A total of 1482 retrieved oocytes were individually cultured and received cIVF or ICSI. The oocytes receiving ICSI were denuded and the number of mature (MII) oocytes was counted.

RESULTS

The oocyte retrieval rates and the proportion of MII oocytes were significantly lower in small follicles than in large follicles. Under cIVF, the fertilization rate was significantly lower in oocytes from small follicles than large follicles. Under ICSI, the fertilization rate for MII oocytes was not significantly related to follicular size. Follicular size was not significantly related to the development potential to blastocyst and pregnancy rate for either the cIVF oocytes or the ICSI oocytes.

CONCLUSIONS

Although the fertilization rate by cIVF is low in oocytes from small follicles due to the lower proportion of mature oocytes, their development potential is comparable to that of oocytes from larger follicles if they could be fertilized. Under ICSI using mature oocytes, their development potential is not related to follicular size.

Building a stem cell-based primate uterus

The uterus is the organ for embryo implantation and fetal development. Most current models of the uterus are centred around capturing its function during later stages of pregnancy to increase the survival in pre-term births. However, in vitro models focusing on the uterine tissue itself would allow modelling of pathologies including endometriosis and uterine cancers, and open new avenues to investigate embryo implantation and human development. Motivated by these key questions, we discuss how stem cell-based uteri may be engineered from constituent cell parts, either as advanced self-organising cultures, or by controlled assembly through microfluidic and print-based technologies.

Changing stimulation protocol on repeat conventional ovarian stimulation cycles does not lead to improved laboratory outcomes

OBJECTIVE

To evaluate whether physicians' choice of ovarian stimulation protocol is associated with laboratory outcomes.

DESIGN

Retrospective cohort study.

SETTING

Single academic center.

PATIENT(S)

The subjects were 4,458 patients who completed more than one in vitro fertilization ovarian stimulation cycle within 1 year. On second stimulation, 49% repeated the same protocol and 51% underwent a different one.

INTERVENTION(S)

Estradiol priming antagonist, antagonist +/- oral contraceptive pill priming, long luteal protocol, Lupron (Lupron [AbbVie Inc, North Chicago, IL]) stop protocol, and flare were compared. Logistic or linear regression with cluster robust standard errors to account for covariates and paired data was used.

MAIN OUTCOME MEASURE(S)

Oocytes collected (OC), fertilization rate, blastocyst progression (BP), usable embryos (UE), and euploid rate (ER).

RESULT(S)

First stimulation outcomes were comparable across all protocols for FR, BP, UE, and ER but were different for OC, after adjustment for covariates. For OC, the effect of switching protocols differed according to the type of the second stimulation. There was improvement in OC if the same stimulation was repeated, except for flare. In addition, there were slight, significant improvements in fertilization rate (difference in values or coefficient of 0.02; 95% confidence interval [CI], 0.004, 0.4) and UE (coefficient 1.25; 95% CI, 0.79, 1.72) when the same stimulation was repeated. There were no changes in BP (coefficient 0.03; 95% CI, -0.01, 0.08) or ER (coefficient 0.01; 95% CI, -0.04, 0.06) when protocols were changed. In a low-BP subgroup, greater improvement was seen when the same protocol was repeated (coefficient 0.03; 95% CI 0.01, 0.04).

CONCLUSION(S)

There was a slight but significant improvement in laboratory outcomes when the same stimulation protocol was repeated, so careful consideration should be made before switching stimulation protocols for the purpose of improving laboratory outcomes.

Acupuncture for Poor Ovarian Response: A Randomized Controlled Trial

Acupuncture is believed to improve ovarian reserve and reproductive outcomes in women undergoing in vitro fertilization (IVF). This study was conducted to evaluate the effect of network-optimized acupuncture followed by IVF on the oocyte yield in women showing a poor ovarian response. This study was an exploratory randomized controlled trial conducted from June 2017 to January 2020 at the Pusan National University Hospital. Women diagnosed with poor ovarian response were enrolled and randomly divided into two groups: IVF alone and Ac + IVF groups (16 acupuncture sessions before IVF treatment). Eight acupoints with high degree centrality and betweenness centrality were selected using network analysis. Among the participants, compared with the IVF treatment alone, the acupuncture + IVF treatment significantly increased the number of retrieved mature oocytes in women aged more than 37 years and in those undergoing more than one controlled ovarian hyperstimulation cycle. The negative correlation between the number of retrieved mature oocytes and consecutive controlled ovarian hyperstimulation cycles was not observed in the Ac + IVF group irrespective of the maternal age. These findings suggest that physicians can consider acupuncture for the treatment of women with poor ovarian response and aged > 37 years or undergoing multiple IVF cycles.

Association of Assisted Reproductive Technology Treatments with Imprinting Disorders

Assisted reproductive technology (ART) is a broad field in infertility that encompasses different types of treatments. These revolutionary treatment methods aimed to aid infertile or subfertile couples. Treatment was expanded exponentially, as 1 to 3% of the births worldwide takes place with ART procedures. However, treatment is not flawless. Gametes and embryos are exposed to different chemicals and stress through treatment, which leads to disturbance in proper embryo development and results in prenatal and congenital anomalies. When compared with in-vivo development of gametes and preimplantation embryos in mice, in-vitro conditions during ART treatments have been suggested to disturb the gene expression levels, especially imprinted genes. Therefore, ART has been suggested to be associated with increased incidences of different imprinting disorders such as Beckwith–Wiedemann syndrome, Angelman syndrome, and Silver–Russell syndrome, as proved by different case reports and studies. This literature review aims to explain the association of imprinting disorders with this revolutionary treatment procedure.

Important parameters affecting quality of vitrified donor oocytes

For group of 281 oocytes obtained from 43 stimulated donors and cryopreserved by vitrification protocol using Cryotop and Kitazato medium we determined important parameters of oocytes collection and vitrification processes which strongly affect the probability that warmed oocytes will produce high-quality embryos for transfer. The probability to obtain high-quality embryos for transfer from vitrified and warmed oocytes was highest when two conditions were fulfilled: 1. oocytes were incubated before vitrification for 7-10 h and 2. stimulated ovaries of donors in one cycle produced a smaller number of oocytes (<7 oocytes from one donor per stimulated cycle). The probable reasons for these observations were: 1. early vitrification (less than 7 h) before final oocyte metaphase II maturation negatively affected the crucial process of post-warm remodelling of spindles and chromosomes, which reduced the fertilization and utilization rates, 2. the evaluated vitrification protocol amplifies negative impact of membrane defects of oocytes of those cohorts containing more than 6 oocytes - freezing places great demands on the integrity and elasticity of the cell membranes. The fact that cryopreservation influences a complex state of oocytes was confirmed by confocal microscopy.

Ovulation Induction Changes Epigenetic Marks of Imprinting Genes in Mice Fetus Organs

Objective

Genomic imprinting is an epigenetic phenomenon that plays a critical role in normal development of embryo. Using exogenous hormones during assisted reproductive technology (ART) can change an organism hormonal profile and subsequently affect epigenetic events. Ovarian stimulation changes gene expression and epigenetic pattern of imprinted genes in the organs of mouse fetus.

Materials and Methods

For this experimental study, expression of three imprinted genes H19, Igf2 (Insulin-like growth factor 2) and Cdkn1c (Cyclin-dependent kinase inhibitor 1C), which have important roles in development of placenta and embryo, and the epigenetic profile of their regulatory region in some tissues of 19-days-old female fetuses, from female mice subjected to ovarian stimulation, were evaluated by quantitative reverse-transcription PCR (qRT-PCR) and Chromatin immunoprecipitation (ChIP) methods.

Results

H19 gene was significantly lower in heart (P<0.05), liver (P<0.05), lung (P<0.01), placenta (P<0.01) and ovary (P<0.01). It was significantly higher in kidney of ovarian stimulation group compared to control fetuses (P<0.05). Igf2 expression was significantly higher in brain (P<0.05) and kidney (P<0.05), while it was significantly lower in lung of experimental group fetuses in comparison with control fetuses (P<0.05). Cdkn1c expression was significantly higher in lung (P<0.05). It was significantly decreased in placenta of experimental group fetuses rather than the control fetuses (P<0.05). Histone modification data and DNA methylation data were in accordance to the gene expression profiles.

Conclusion

Results showed altered gene expressions in line with changes in epigenetic pattern of their promoters in the ovarian stimulation group, compared to normal cycle.

The identification of novel mutations in PLCZ1 responsible for human fertilization failure and a therapeutic intervention by artificial oocyte activation

Fertilization involves a series of molecular events immediately following egg-sperm fusion; Ca2+ oscillations are the earliest signaling event, and they initiate the downstream reactions including pronucleus formation. Successful human reproduction requires normal fertilization. In clinical IVF or ICSI attempts, some infertile couples suffer from recurrent fertilization failure. However, the genetic reasons for fertilization failure are largely unknown. Here, we recruited several couples diagnosed with fertilization failure even though their gametes are morphologically normal. Through whole-exome sequencing and Sanger sequencing, we identified biallelic mutations in gene-encoding phospholipase C zeta 1 (PLCZ1) in four independent males in couples diagnosed with fertilization failure. Western blotting showed that missense mutations decreased the level of PLCZ1 and that nonsense or frameshift mutations resulted in undetectable or truncated proteins. Expression of these mutations in mice significantly reduced the levels of oocyte activation. Artificial oocyte activation in patient oocytes could rescue the phenotype of fertilization failure and help establish pregnancy and lead to live birth. Our findings expand the spectrum of PLCZ1 mutations that are responsible for human fertilization failure and provide a potentially feasible therapeutic treatment for these patients.

Description of the Follicular Fluid Cytokine and Hormone Profiles in Human Physiological Natural Cycles

PURPOSE

Exogenous gonadotrophins administration during in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) cycles could significantly alter the endogenous follicular regulation system and could influence oocyte quality. The analysis of the follicular fluid (FF) cytokine and hormone profiles in physiological natural cycles is crucial to appreciate the role of FF milieu on follicle development. So far, the FF cytokine profile has been analyzed only in controlled ovarian stimulation cycles and in modified natural cycles. Our study defines, in physiological natural cycles, the cytokine and hormone profiles of individual FF aspirated from antral follicles.

METHODS

A total of 203 FFs obtained from 83 women with regular menstrual cycles undergoing ovarian tissue cryopreservation were analyzed: 115 FFs from Group 1 (10 to 29 years of age) and 88 FFs from Group 2 (30 to 40 years of age). In individual FF, 27 cytokines were measured with xMAP technology, and progesterone, estrone, estradiol, testosterone, androstenedione concentrations were determined by liquid chromatography-tandem mass spectrometry.

RESULTS

FF hormone profiles were not different in follicular and luteal phase, suggesting that FF hormones are regulated independently of the endogenous gonadotrophins-possibly because 74% of the punctured follicles, which were ≤6 mm, did not require cyclic pituitary function. The follicle size was influenced not only by the FF cytokine profile but also by the FF hormone profile, both of which are dependent on age.

MAIN CONCLUSIONS

In physiological natural cycles, FF hormones seems to be regulated independently of the endogenous gonadotropins. Age influences FF hormone and cytokine profiles and the compelling relationship between FF hormones and FF cytokines could influence the follicle development.

Mitochondrial DNA in Fresh versus Frozen Embryo Culture Media of Polycystic Ovarian Syndrome Patients Undergoing Invitro Fertilization: A Possible Predictive Marker of a Successful Pregnancy

Purpose

Frozen embryos transfer (ET) may improve the live-birth and reduce rates of ovarian hyperstimulation in polycystic ovary syndrome (PCOS) patients. Morphological criteria are the classical way for embryo selection, yet recently, many biochemical and genetic markers have been developed. This study aimed to compare fresh and frozen ET using the mtDNA/gDNA ratio of embryo secretome and the possibility of using this ratio as a predictive marker of PCOS pregnancy rate.

Subjects and Methods

One hundred PCOS patients undergoing IVF were chosen according to Rotterdam criteria and divided into two groups. Group I (50 with fresh ET), group II (50 with frozen ET), and otherwise 33 apparently healthy women as a control group with fresh ET. We then carried out absolute quantification of embryo culture media mtDNA and gDNA by real-time PCR.

Results

mtDNA/gDNA ratio was significantly low in PCOS embryo culture media in comparison with control. Additionally, while the mtDNA/gDNA ratio was significantly high in pregnant PCOS embryo culture media, it was high, though not statistically significant, in the fresh ET than frozen ET group. mtDNA/gDNA ratio sensitivity and specificity in PCOS embryo culture media as a predictive value of pregnancy rate were (86% and 96%, respectively).

Conclusion

mtDNA/gDNA ratio measurement in PCOS embryo culture media is a novel marker that can be clinically applied as a predictive value of the quality of the morphologically good embryo.

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miR223-3p, HAND2, and LIF expression regulated by calcitonin in the ERK1/2-mTOR pathway during the implantation window in the endometrium of mice

PROBLEM

Approximately one-third of infertility cases are related to the female partner, and implantation failure is the primary reason for female infertility. The current research was established to assess the impact of calcitonin on endometrial receptivity.

METHODS OF STUDY

64 female BALB/c mice were assigned to 2 groups as follows: mice with regular ovarian cycle and mice with stimulated ovarian cycle. The two groups were further divided into four subgroups as follows: control (Ctrl), calcitonin (CT), pp242, and CT + pp242 groups. Calcitonin and pp242 were injected on days 3, 4, and 5 of pregnancy. On day 5 of gestation, all of the animals were sacrificed, and their uterine was removed for the morphological analysis, as well as the expression assessment genes and proteins.

RESULTS

The results demonstrated that ovarian stimulation increased the rate of phosphorylation of ERK1/2 and mTOR proteins, and resulted in the upregulation of miR-223-3p. The administration of calcitonin also elevated the expression levels of LIF and HAND2 gene in both regular ovarian and ovarian-stimulated cycles. In ovarian-stimulated groups, the administration of calcitonin led to a decrease in the expression of miR-223-3p. Calcitonin administration also markedly increased the phosphorylation of 4EBP1 and ERK1/2 in the regular ovarian cycle.

CONCLUSION

It seems that calcitonin is capable of enhancing the endometrial receptivity of the uterine, thereby the overexpression of HAND2 and LIF and downregulation of miR-223-3p through the ERK1/2-mTOR signaling pathway.

Small Noncoding RNA Signatures for Determining the Developmental Potential of an Embryo at the Morula Stage

As part of the optimization of assisted reproductive technology programs, the aim of the study was to identify key small noncoding RNA (sncRNA) molecules that participate in maternal-to-zygotic transition and determine development potential and competence to form a healthy fetus. Small RNA deep sequencing followed by quantitative real-time RT-PCR was used to profile sncRNAs in 50 samples of spent culture medium from morula with different development potentials (no potential (degradation/developmental arrest), low potential (poor-quality blastocyst), and high potential (good/excellent quality blastocyst capable of implanting and leading to live birth)) obtained from 27 subfertile couples who underwent in vitro fertilization. We have shown that the quality of embryos at the morula stage is determined by secretion/uptake rates of certain sets of piRNAs and miRNAs, namely hsa_piR_011291, hsa_piR_019122, hsa_piR_001311, hsa_piR_015026, hsa_piR_015462, hsa_piR_016735, hsa_piR_019675, hsa_piR_020381, hsa_piR_020485, hsa_piR_004880, hsa_piR_000807, hsa-let-7b-5p, and hsa-let-7i-5p. Predicted gene targets of these sncRNAs included those globally decreased at the 8-cell–morula–blastocyst stage and critical to early embryo development. We show new original data on sncRNA profiling in spent culture medium from morula with different development potential. Our findings provide a view of a more complex network that controls human embryogenesis at the pre-implantation stage. Further research is required using reporter analysis to experimentally confirm interactions between identified sncRNA/gene target pairs.

Length of ovarian stimulation does not impact live birth rate in fresh donor oocyte cycles: a SART CORS study

PURPOSE

To evaluate the effect of controlled ovarian hyperstimulation length and total gonadotropin (GN) dose on recipient live birth rate (LBR) in fresh donor oocyte cycles.

METHODS

Data was obtained from SART CORS on all fresh donor oocyte GnRH antagonist cycles (n = 1049) between 2014 and 2015 which resulted in a single embryo transferred. Donor and recipient demographic information and cycle characteristics were extracted. Binomial regression was used to estimate LBR with respect to days of stimulation (DOS) and total GN dose. Multivariate analysis was performed to evaluate these relationships after controlling for confounders.

RESULTS

Overall LBR in fresh donor oocyte cycles was 57%. Average stimulation length was 14.3 ± 4.9 days, and total GN dose was 2464 ± 1062 IU. On univariate analysis, neither days of stimulation (p = 0.5) nor total GN dose (p = 0.57) was independently correlated with LBR. However, in prolonged stimulations (> 15 days) with high total GN dose (> 3000 IU), as both the cycle length and total GN dose increased, LBR significantly decreased from 63.81 to 48.15% (p = 0.02) and from 67.61 to 48.15% (p = 0.01), respectively. Multivariate analysis showed no significant effect of either DOS or total GN dose on LBR.

CONCLUSIONS

LBR is significantly decreased in fresh donor oocyte cycles when cycles are prolonged with high total GN dose. However, after controlling for confounders neither DOS nor total GN dose significantly affects LBR.

Efficacy of the delayed start antagonist protocol for controlled ovarian stimulation in Bologna poor ovarian responders: a systematic review and meta-analysis

BACKGROUND

Patients with a poor ovarian response (POR) represent the most difficult group of population to deal with in the clinical fertility practice. Bologna criteria are the first uniform definition of POR. Choosing a suitable controlled ovarian stimulation (COS) protocol which could give adequate oocytes to maximize the chance of obtaining at least one euploid blastocyst is crucial in the management for such patients. The delayed start antagonist protocol is a novel COS protocol designed for POR patients, however, its real efficacy is controversial compared to conventional protocols. The present study aims to summarize all available studies on this topic and perform a meta-analysis to explore the real treatment effect of this novel protocol in terms of reproductive outcomes.

STUDY DESIGN

PubMed, EMBASE, Google Scholar, and the Cochrane Library from database establishment to June 2019 were searched. Randomized controlled trials (RCTs), which compared delayed start antagonist protocol (Del) to conventional controlled ovarian stimulation (COS) protocols (Con) in terms of reproductive outcomes, were included. The RevMan 5.3 was used to perform statistical analysis. The primary outcomes were the cycle cancellation rate, the clinical pregnancy rate and the miscarriage rate.

RESULTS

5 RCTs yielding 514 patients were eligible, of which 5, 5, 4 studies were included in analyzing the cycle cancellation rate, the clinical pregnancy rate, and the miscarriage rate respectively. Synthesized data of meta-analysis showed: delayed start antagonist protocol introduced a lower risk of cycle cancellation [risk ratio (RR) = 0.63, 95% confidence interval (CI) (0.45, 0.90), P = 0.01; 5 RCTs, 514 women (Del:Con = 256:258); I² = 0%; with rates of 16.02% (Del) vs. 26.36% (Con)], an increased chance to get clinical pregnancy [RR = 2.30, 95% CI (1.38, 3.82), P = 0.001; 5 RCTs, 514 women (Del:Con = 256:258); I² = 0%; with rates of 16.80% (Del) vs. 7.36% (Con)], and a comparable miscarriage rate [RR = 0.55, 95% CI (0.24, 1.23), P = 0.15; 4 RCTs, 58 women (Del:Con = 41:17) I² = 17%; with rates of 19.51% (Del) vs. 35.29% (Con)] compared to conventional COS protocols.

CONCLUSIONS

Delayed start antagonist protocol was a potentially valuable alternation for poor ovarian responders. However, future RCTs with large sample size and more scientific design are needed to verify its validity and draw a sound conclusion.

Differential impact of controlled ovarian hyperstimulation on live birth rate in fresh versus frozen embryo transfer cycles: a Society for Assisted Reproductive Technology Clinic Outcome System study

OBJECTIVE

To study the impact of both controlled ovarian hyperstimulation (COH) length and total gonadotropin (GN) dose individually and in concert on live birth rates (LBR) in both fresh and freeze-all in vitro fertilization embryo transfer (IVF-ET) cycles.

DESIGN

Historical cohort study.

SETTING

Not applicable.

PATIENT(S)

The U.S. national database from the Society of Assisted Reproductive Technology Clinic Outcome Reporting System from 2014 to 2015 was used to identify patients undergoing autologous GN stimulation IVF cycles with the use of GnRH antagonist-based suppression protocols where a single embryo transfer was performed as part of a fresh IVF-ET cycle (fresh, n = 14,866) or the first frozen embryo transfer after a freeze-all cycle (frozen, n = 2,964), and not including preimplantation genetic testing cycles. The patients' demographic and cycle characteristics, duration of COH, total GN dose, and pregnancy outcomes were extracted. Binomial regression models estimated trend and relative risk of live birth with respect to days of stimulation and total GN dose singularly, and after adjustment for a priori confounders including age, parity, body mass index, diagnosis, and maximum follicle-stimulating hormone in both fresh and frozen embryo transfer cycles. Both days of stimulation and total GN dose were then added to the multivariate model to show whether they were independently associated with LBR.

INTERVENTION(S)

Not applicable.

MAIN OUTCOME MEASURE(S)

Live birth rate.

RESULTS

In both fresh and frozen cycles, length of COH was significantly associated with total GN dose. On univariate analysis, LBR decreased significantly with increasing length of stimulation and increasing total GN dose in both fresh and frozen cycles. On multivariable analysis including both days of stimulation and total GN dose, days of stimulation was no longer significantly correlated with LBR, whereas total GN dose remained significantly correlated with LBR in fresh cycles only. When total GN doses ranging from <2,000 IU through 5,000 IU to >5,000 IU were compared, a significant improvement in live birth rate was noted with lower total GN doses. Specifically, GN doses <2,000 IU had a 27% higher rate of live birth compared with GN dose >5,000 IU. For GN dose groups up to 4,000 IU, the estimated effect on LBR was similar. There was a marginal improvement (13%) in LBR with GN doses of 4,000 IU to 5,000 IU compared with >5,000 IU. When the multivariate model was applied to the frozen cycles, neither total GN dose nor days of stimulation was significantly associated with LBR.

CONCLUSIONS

High total GN dose but not prolonged COH is associated with decreasing LBRs in fresh cycles, whereas neither factor significantly affects LBR in frozen cycles. Consideration should be given to minimizing the total GN dose when possible in fresh autologous cycles, either by decreasing the daily dose or by limiting the length of stimulation to improve LBRs. In freeze-all cycles, the use of higher GN doses does not seem to adversely affect the LBR of the first frozen embryo transfer. High total GN dose likely exerts a negative impact on the endometrium and/or oocyte/embryo unrelated to the length of stimulation. The differential effect of total GN dose on LBR in fresh and frozen cycles may imply a greater impact exerted on the endometrium rather than the oocyte.

Aberrant spliceosome expression and altered alternative splicing events correlate with maturation deficiency in human oocytes

Different strategies of ovarian stimulation are widely used in IVF to retrieve mature metaphase II (MII) oocytes for fertilization. On average, approximately 70% of recovered oocytes are mature, while personalized administration of hCG and/or GnRH agonist trigger and in vitro maturation (IVM) management can further improve the maturation rate. However, even under such conditions, a complete absence of oocyte maturation is still observed sporadically. The probable causes for such maturation-deficient (MD) oocytes - which arrest abnormally at metaphase I (MI) stage - are still under investigation. In the present study, using single-cell transcriptomic RNA sequencing (RNA-seq) and differential expression analysis, we showed that gene expression profiles were aberrant, and alternative splicing (AS) patterns were changed in MD oocytes when compared with normally mature (MN) oocytes. Gene ontology (GO) enrichment demonstrated that the differently expressed genes (DEGs) were mostly correlated with pre-mRNA splicing, RNA transportation, RNA processing, and mRNA regulation. Subsequently, analysis of AS events revealed that genes with altered AS patterns were primarily associated with metabolism and cell cycle. With these findings, we have demonstrated aberrant gene expression in complete maturation-deficient oocytes, and we propose that alterations in post-transcriptional regulation constitute a potential underlying mechanism governing oocyte maturation.

Higher probability of live-birth in high, but not normal, responders after first frozen-embryo transfer in a freeze-only cycle strategy compared to fresh-embryo transfer: a meta-analysis

STUDY QUESTION

Does the outcome of the comparison of live birth rates between the first frozen embryo transfer (ET) (in a freeze-only cycles strategy, i.e. frozen ET group) and a fresh embryo transfer (fresh ET group) differ considering the type of ovarian response?

SUMMARY ANSWER

Α significantly higher probability of live birth is present in high, but not normal, responders, after the first frozen ET in a freeze-only cycle strategy as compared to a fresh ET.

WHAT IS KNOWN ALREADY

It has been hypothesised that freezing all good embryos in a fresh in-vitro fertilisation (IVF) cycle and deferring embryo transfer in subsequent cycles may provide a more physiological endometrial environment for embryo implantation when compared to a fresh ET. However, currently, three relevant meta-analyses have been published with conflicting results, while none of them has taken into consideration the type of ovarian response. Recently, the publication of additional, large relevant randomised controlled trials (RCTs) in patients with different types of ovarian response makes possible the comparative evaluation of the first frozen ET (in a freeze-only cycle strategy) versus fresh ET, considering the type of ovarian response.

STUDY DESIGN, SIZE, DURATION

A systematic review and meta-analysis was performed aiming to identify RCTs comparing the first frozen ET (in a freeze-only cycle strategy) to a fresh ET. The main outcome was live birth, while secondary outcomes included ongoing pregnancy, clinical pregnancy, moderate/severe ovarian hyperstimulation syndrome (OHSS) and miscarriage.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We identified eight eligible RCTs, including 5265 patients, which evaluated the first frozen ET in a freeze-only cycle strategy versus a fresh ET either in high responders (n = 4) or in normal responders (n = 4). No relevant RCTs were present in poor responders. Meta-analysis of weighted data using fixed and random effects model was performed. Results are reported as relative risk (RR) with 95% confidence interval (CI).

MAIN RESULTS AND THE ROLE OF CHANCE

Eligible RCTs were published between 2011 and 2018. Four RCTs (n = 3255 patients) compared the first frozen ET (in a freeze-only cycle strategy) to a fresh ET in normal responders and four RCTs (n = 2010 patients) did the comparison in high responders. In high responders, a significantly higher probability of live birth was observed in the frozen ET group when compared with the fresh ET group (RR: 1.18, 95% CI: 1.06-1.31; fixed effects model; heterogeneity: I2 = 0%; three studies; n = 3398 patients). However the probability of live birth was not significantly different between the frozen ET group and the fresh ET group in normal responders (RR: 1.13, 95% CI: 0.90-1.41; random effects model; heterogeneity: I2 = 77%; three studies; n = 1608 patients). The risk of moderate/severe OHSS was significantly lower in the frozen ET group when compared with the fresh ET group both in high (RR: 0.19, 95% CI: 0.10-0.37; fixed effects model; heterogeneity: not applicable; a single study; n = 1508 patients) and normal responders (RR: 0.39, 95% CI: 0.19-0.80; fixed effects model; heterogeneity: I2 = 0%; two studies; n = 2939 patients).

LIMITATIONS, REASONS FOR CAUTION

Considerable heterogeneity was present among the studies, regarding ovarian stimulation protocols and the triggering signal used for inducing final oocyte maturation as well as the cryopreservation methods, while the quality of evidence was poor for the live birth rate in high responders. Moreover, the analysis did not apply a standard for determining 'high' or 'normal' responders since the type of ovarian response followed the characterisation of populations as reported by the authors of the eligible studies.

WIDER IMPLICATIONS OF THE FINDINGS

A freeze-only cycle strategy should be the preferred option in high responders since it enhances the probability of live birth, while reducing the chance of moderate/severe OHSS. In normal responders, the same strategy could be applied, in the interest of patient safety or clinic convenience, without compromising the chances of live birth.

STUDY FUNDING/COMPETING INTEREST(S)

No external funding was used and there were no competing interests.

PROSPERO REGISTRATION NUMBER

PROSPERO registration number: CRD42018099389.

Single-cell DNA methylation sequencing reveals epigenetic alterations in mouse oocytes superovulated with different dosages of gonadotropins

BACKGROUND

Epigenetic abnormalities caused by superovulation have recently attracted increasing attention. Superovulation with exogenous hormones may prevent oocytes from establishing an appropriate epigenetic state, and this effect may extend to the methylation programming in preimplantation embryos, as de novo DNA methylation is a function of developmental stage of follicles and oocyte size. Follicle-stimulating hormone (FSH) and human menopausal gonadotropin (hMG) are common gonadotropins used for superovulation, and appropriate concentrations of these gonadotropins might be necessary. However, no systematic study on the effects of DNA methylation alterations in oocytes associated with superovulation with different dosages of FSH/hMG at the single-cell level has yet been reported. In the current study, different dosages of FSH/hMG combined with human chorionic gonadotropin (hCG) were used in female mice to generate experimental groups, while naturally matured oocytes and oocytes superovulated with only hCG were respectively used as controls. Single-cell level DNA methylation sequencing was carried out on all these matured oocytes.

RESULTS

In this study, we revealed that the genome-wide methylation pattern and CG methylation level of the maternal imprinting control regions of all mature oocytes were globally conserved and stable. However, methylation alterations associated with superovulation were found at a specific set of loci, and the differentially methylated regions (DMRs) mainly occurred in regions other than promoters. Furthermore, some of the annotated genes in the DMRs were involved in biological processes such as glucose metabolism, nervous system development, cell cycle, cell proliferation, and embryo implantation and were altered in all dosages of FSH/hMG group (for example, Gfod2 and SYF2). Other genes were impaired only after high gonadotropin dosages (for instance, Sox17 and Phactr4).

CONCLUSIONS

In conclusion, the current study addressed the effects of superovulation on DNA methylation from the perspective of different dosages of gonadotropins at the single-cell level. We found that the genome-wide DNA methylation landscape was globally preserved irrespective of superovulation or of the kind and dosage of gonadotropins used, whereas the methylation alterations associated with superovulation occurred at a specific set of loci. These observed effects reflect that superovulation recruits oocytes that would not normally be ovulated or that have not undergone complete epigenetic maturation. Our results provide an important reference for the safety assessment of superovulation with different dosages of gonadotropins. However, it should be noted that this study has some limitations, as the sample number and library coverage of analyzed oocytes were relatively low. Future studies with larger sample sizes and high-coverage libraries that examine the effects of superovulation on embryo development and offspring health as well as the underlying mechanisms are still needed.

Effect of ovarian stimulation on the expression of piRNA pathway proteins

PIWI-interacting RNAs (piRNAs) play an important role in gametogenesis, fertility and embryonic development. The current study investigated the effect of different doses of pregnant mare serum gonadotrophin/human chorionic gonadotrophin (PMSG/hCG) and repeated ovarian stimulation (OS) on the expression of the Mili, Miwi, Mael, Tdrd1, Tdrd9, qnd Mitopld genes, which have crucial roles in the biogenesis and function of piRNAs. Here, we found that after treatment with 7.5 I.U. PMSG/hCG and two repeated rounds of OS, both the mRNA and protein levels of Tdrd9, Tdrd1 and Mael showed the greatest decrease in the ovarian tissue, but the plasma E₂ levels showed the strongest increases (p<0.05). However, we found that the Mitopld, Miwi and Mili gene levels were decreased significantly after treatment with 12.5 I.U. PMSG/hCG. Our results suggested that exogenous gonadotropin administration leads to a significant decrease in the expression of the Mili, Miwi, Mael, Tdrd1, Tdrd9 and Mitopld genes, which are critically important in the piRNA pathway, and the changes in the expression levels of Tdrd9, Tdrd1 and Mael may be associated with plasma E₂ levels. New comprehensive studies are needed to reduce the potential effects of OS on the piRNA pathway, which silences transposable elements and maintains genome integrity, and to contribute to the safety of OS.

Involvement of CDKN1A (p21) in cellular senescence in response to heat and irradiation stress during preimplantation development

This study examined the role of cyclin-dependent kinase inhibitor 1a (CDK1A, p21) in response to exogenous stressors during mouse preimplantation embryo development. CDKN1A knockdown (KD) one-cell zygotes were exposed to 39 °C heat stress (HS) for 4 days or irradiated by 1 (1-Gy) or 3 (3-Gy) Gy X-rays, and their developmental competence and gene expression were compared with control embryos. CDKN1A KD and HS did not influence early cleavage or subsequent embryonic development; however, HS delayed cavitation and induced elevated Cdkn1a expression in control embryos. Exposure to 1- or 3-Gy had no effect on development to the morula stage; however, a significant number of morulae failed to develop to the blastocyst stage. Interestingly, under the 1-Gy condition, the blastocyst rate of CDKN1A KD embryos (77.7%) was significantly higher than that of the controls (44.4%). In summary, exposure to cellular stressors resulted in the upregulation of Cdkn1a in embryos exposed to HS or X-ray irradiation, particularly in response to heat stress or low-dose X-ray irradiation, and depleting Cdkn1a mRNA alleviated cell cycle arrest. These findings suggest that CDKN1A plays a vital role in cellular senescence during preimplantation embryo development.

Reactive oxygen species in reproduction: harmful, essential or both?

The process of embryonic development is crucial and radically influences preimplantation embryo competence. It involves oocyte maturation, fertilization, cell division and blastulation and is characterized by different key phases that have major influences on embryo quality. Each stage of the process of preimplantation embryonic development is led by important signalling pathways that include very many regulatory molecules, such as primary and secondary messengers. Many studies, both in vivo and in vitro, have shown the importance of the contribution of reactive oxygen species (ROS) as important second messengers in embryo development. ROS may originate from embryo metabolism and/or oocyte/embryo surroundings, and their effect on embryonic development is highly variable, depending on the needs of the embryo at each stage of development and on their environment (in vivo or under in vitro culture conditions). Other studies have also shown the deleterious effects of ROS in embryo development, when cellular tissue production overwhelms antioxidant production, leading to oxidative stress. This stress is known to be the cause of many cellular alterations, such as protein, lipid, and DNA damage. Considering that the same ROS level can have a deleterious effect on the fertilizing oocyte or embryo at certain stages, and a positive effect at another stage of the development process, further studies need to be carried out to determine the rate of ROS that benefits the embryo and from what rate it starts to be harmful, this measured at each key phase of embryonic development.

The Influence of Delayed Blastocyst Development on the Outcome of Frozen-Thawed Transfer of Euploid and Untested Embryos

Objective

The primary objective is to compare live birth rates (LBRs) following frozen embryo transfer (FET) of euploid day 5 with day 6 blastocysts. We also compared LBRs following FET of untested blastocysts vitrified on day 5 and day 6 in self-oocyte and ovum donation (OD) cycles.

Design

This was a retrospective observational study.

Setting

Nova IVF Fertility, Ahmedabad.

Materials and Methods

Ninety-seven FET using self-oocytes following preimplantation genetic testing A (PGT-A), 464 FET following OD, and 907 FET using self-oocytes without PGT-A testing between January 2016 and December 2017 were included in this study.

Main Outcome Measures

LBR following FET in day 5 versus day 6 blastocysts in euploid embryos using self-oocytes and in untested embryos using both self and donor oocytes.

Results

In PGT-A cycles, no statistically significant difference was observed in LBRs following transfer of euploid blastocysts developed on day 5 or day 6 (D5: 53%; D6:40%, P = 0.83). However, the LBRs with day 5 blastocysts were higher compared with day 6 group in untested group using both self and donor oocytes (self D5: 52.7%; D6: 38.2%; P = 0.001 and OD D5: 44.7%; D6: 29.8%; P = 0.001). Miscarriage rates were comparable in both the groups.

Conclusions

The present study demonstrated comparable pregnancy outcomes following FET of euploid embryos vitrified on day 5 and day 6. However, higher LBRs were reported in day 5 group in untested embryos.

HDAC3 maintains oocyte meiosis arrest by repressing amphiregulin expression before the LH surge

It is known that granulosa cells (GCs) mediate gonadotropin-induced oocyte meiosis resumption by releasing EGF-like factors in mammals, however, the detailed molecular mechanisms remain unclear. Here, we demonstrate that luteinizing hormone (LH) surge-induced histone deacetylase 3 (HDAC3) downregulation in GCs is essential for oocyte maturation. Before the LH surge, HDAC3 is highly expressed in GCs. Transcription factors, such as FOXO1, mediate recruitment of HDAC3 to the amphiregulin (Areg) promoter, which suppresses AREG expression. With the LH surge, decreased HDAC3 in GCs enables histone H3K14 acetylation and binding of the SP1 transcription factor to the Areg promoter to initiate AREG transcription and oocyte maturation. Conditional knockout of Hdac3 in granulosa cells in vivo or inhibition of HDAC3 activity in vitro promotes the maturation of oocytes independent of LH. Taking together, HDAC3 in GCs within ovarian follicles acts as a negative regulator of EGF-like growth factor expression before the LH surge.

Before ovulation, a surge of luteinizing hormone (LH) triggers the resumption of meiosis in oocytes, which is mediated by EGF-like growth factors. Here, the authors show that HDAC3 inhibits mouse oocyte maturation by negatively regulating the expression of EGF-like factor before the LH surge.

Ovarian stimulated cycles reduce protection of follicular fluid against free radicals

Controlled ovarian hyperstimulation cycle with exogenous gonadotropins (COH) is associated with clinical complications. The aim of this work was to determine whether COH alters the physiological antioxidant status of follicular fluid in women with no reproductive dysfunction, compared to the natural cycle (NC). In this longitudinal study, forty-one women (oocyte donors) consecutively underwent NC and COH. Follicular fluid was collected at oocyte retrieval and different redox biomarkers were determined: total antioxidant activity (TAA), oxygen radical absorbance capacity (ORAC), nitric oxide, α- and γ-tocopherol, the fatty acid composition, activities of superoxide dismutase, catalase, total and Se-dependent glutathione peroxidases, and the antioxidant paraoxonase (PON) family. Results showed that TAA (1.70 ± 0.03 mM versus 1.86 ± 0.03 mM, p < 0.05), α-tocopherol (4.37 ± 0.26 μM versus 5.74 ± 0.30 μM, p < 0.05), PON1 paraoxonase (245 ± 24 nmol/min/ml versus 272 ± 27 nmol/min/ml, p < 0.05), PON1 arylesterase (87.2 ± 4.6 μmol/min/ml versus 99.3 ± 4.8 μmol/min/ml, p < 0.05), and PON3 simvastatinase (13.48 ± 0.52 nmol/min/ml versus 16.29 ± 0.72 nmol/min/ml, p < 0.001) were significantly lower in COH versus NC. Fatty acids from COH were more saturated, increasing palmitate and decreasing the n-6 and total polyunsaturated fatty acids (PUFAs). Docosahexaenoic acid also increased (p < 0.05). Results suggest that COH could lead to premature ovarian aging and provide new insights into the possible prevention of the adverse effects of ovarian hyperstimulation by directing therapeutic applications to the maintenance of the redox balance and fatty acid status, with special attention to paraoxonase proteins and docosahexaenoic acid.

Segregating Chromosomes in the Mammalian Oocyte

Chromosome segregation errors in human oocytes lead to aneuploid embryos that cause infertility and birth defects. Here we provide an overview of the chromosome-segregation process in the mammalian oocyte, highlighting mechanistic differences between oocytes and somatic cells that render oocytes so prone to segregation error. These differences include the extremely large size of the oocyte cytoplasm, the unique geometry of meiosis-I chromosomes, idiosyncratic function of the spindle assembly checkpoint, and dramatically altered oocyte cell-cycle control and spindle assembly, as compared to typical somatic cells. We summarise recent work suggesting that aging leads to a further deterioration in fidelity of chromosome segregation by impacting multiple components of the chromosome-segregation machinery. In addition, we compare and contrast recent results from mouse and human oocytes, which exhibit overlapping defects to differing extents. We conclude that the striking propensity of the oocyte to mis-segregate chromosomes reflects the unique challenges faced by the spindle in a highly unusual cellular environment.

PGR and PTX3 gene expression in cumulus cells from obese and normal weighting women after administration of long-acting recombinant follicle-stimulating hormone for controlled ovarian stimulation

PURPOSE

The present study aimed to determine clinical IVF parameters and gene expression in cumulus cells (CCs) in obese and normal weighting women after administration of 150 mcg of corifollitropin alfa for controlled ovarian hyperstimulation (COH).

METHODS

150 mcg of corifollitropin alfa and gonadotropin releasing hormone antagonist were used for COH. Analysis of CC gene expression was performed using quantitative real-time PCR.

RESULTS

We did not find significant differences in biochemical and clinical pregnancy rates between obese and normal weighting women. Obese women required twice as much of additional gonadotropins for ovarian stimulation and had a significantly lower proportion of good quality embryos on day 5 of IVF cycle. Expression of PGR and PTX3 was significantly higher in CCs of obese women.

CONCLUSION

Obese women require significantly larger amounts of gonadotropins to achieve similar IVF success rates as normal weighting women. Differences in CC gene expression and smaller proportion of good quality embryos may imply that oocytes derived from obese women are of lower quality. Further studies are needed to evaluate whether obesity itself or the higher amount of gonadotropins used in obese women causes this effect.

Comparative Effectiveness of Three Ovarian Hyperstimulation Protocol in In Vitro Fertilization (IVF) Cycles for Women with Polycystic Ovary Syndrome

Background

The aim of this study was to evaluate the efficacy of specific in vitro fertilization (IVF) protocols for patients with polycystic ovary syndrome (PCOS), and therefore, analyze the first-rank intention IVF protocol.

Material/Methods

In this study, 408 PCOS patients (464 treatment cycles) were enrolled and assigned to one of 3 groups: group 1 [oral contraceptive long-term regimen group (OC-L protocol group, n=91)], group 2 (GnRH antagonist protocol, n=80), and group 3 [follicular phase long-term regimen group, C₁-L protocol group n=293]. The endpoints are the number of eggs, oocyte maturation rate, high-quality embryo rate and clinical pregnancy rate after fresh embryos transfer, the incidence of ovarian hyperstimulation syndrome and abortion rate.

Results

The number of eggs, oocyte maturation rate, and high-quality embryo rate in the C₁-L protocol group were significantly higher than those in the other 2 groups. The fertilization rate and cleavage rate of the 3 groups were not significantly different. After fresh embryo transplantation, the pregnancy rate of C₁-L protocol group was significantly higher than that of the other groups.

Conclusions

This study showed that the super-long downregulation in follicular phase regimen has advantages of simple treatment process, high oocyte maturation rate, high quality embryo rate, and pregnancy rate. It is a good choice for PCOS patients to promote ovulation during IVF.

Prolonged blastomere movement induced by the delay of pronuclear fading and first cell division adversely affects pregnancy outcomes after fresh embryo transfer on Day 2: a time-lapse study

RESEARCH QUESTION

What is the incidence, origin and clinical significance of blastomere movement after the first cell division in the human embryo?

DESIGN

A total of 1096 embryos, cultured in the EmbryoScope+ ® time-lapse system and subjected to a single fresh cleaved embryo transfer, were retrospectively analysed. Type and duration of blastomere movement (dBMov) between the first (t2) and second cell division (t3) was monitored, and the ratio of dBMov during the 2-cell stage [dBMov/(t3-t2)] was calculated. Morphological evaluation of embryos was performed by referring to the size of the blastomere and fragmentation after first division in addition to Veeck's criteria on Day 2. The correlation between dBMov and ongoing pregnancy was evaluated and the association of dBMov with patient and embryonic characteristics was determined.

RESULTS

Both movement type and the value of dBMov/(t3-t2) were significantly associated with asymmetrical first division, fragment formation and morphological grade on Day 2. Multivariate logistic regression analysis revealed that a higher value of dBMov/(t3-t2) significantly correlated with a decreased ongoing pregnancy rate, even after adjustment for co-founders (odds ratio 0.399, P = 0.0419). The time intervals of pronuclear (PN) alignment and PN fading were significantly correlated with the dBMov/(t3-t2) value.

CONCLUSIONS

Embryos with extended blastomere movement after the first cell division, which is associated with the delay of PN fading and first cell division, have a lower competence to initiate an ongoing pregnancy after fresh embryo transfer on Day 2. Thus, blastomere movement could be a useful predictive parameter for selecting embryos at the early cleavage stage.

Calcitonin administration improves endometrial receptivity via regulation of LIF, Muc-1 and microRNA Let-7a in mice

Calcitonin (CT) is one of the factors affecting the embryo implantation, but its effects on the implantation window have not been fully investigated. The current study investigated the effects of CT on the endometrium receptivity by morphological study and evaluation of leukemia inhibitory factor (LIF), mucin 1 (Muc-1), and microRNA (miRNA) Let-7a in the ovarian stimulation and the normal ovarian cycle. Then the mechanism of the CT effects through the mammalian target of rapamycin (mTOR) signaling pathway was studied by using PP242. A total of 64 BALB/c mice were divided into the normal ovarian cycle and ovarian stimulation groups. Each group consisted of four subgroups: control, calcitonin, PP242, and calcitonin+PP242. CT and PP242 were injected on the fourth of pregnancy into the mice and 24 hr later all the mice were killed. The uterine tissue samples were used for morphological analysis, and endometrial cells were mechanically isolated for evaluation of gene and protein expression. The results showed that ovarian stimulation induced mTOR phosphorylation as well as increased expression of the Let-7a miRNA. In addition, CT injection increased the expression of LIF and miRNA Let-7a in ovarian stimulation similar to that in normal ovarian cycles. However, injection of PP242 reduced expression of miRNA Let-7a and increased Muc-1 expression in ovarian stimulation group. In conclusion, the administration of CT improved endometrial receptivity in mice. This phenomenon occurred by upregulation of LIF, miRNA Let-7a and downregulation of Muc-1 via mTOR signaling pathway.

Risk of prematurity and infant morbidity and mortality by maternal fertility status and plurality

PURPOSE

To evaluate the risk of prematurity and infant mortality by maternal fertility status, and for in vitro fertilization (IVF) pregnancies, by oocyte source and embryo state combinations.

METHODS

Women in 14 States who had IVF-conceived live births during 2004-13 were linked to their infant's birth and death certificates; a 10:1 sample of non-IVF births was selected for comparison; those with an indication of infertility treatment on the birth certificate were categorized as subfertile, all others were categorized as fertile. Risks were modeled separately for the fertile/subfertile/IVF (autologous-fresh only) group and for the IVF group by oocyte source-embryo state combinations, using logistic regression, and reported as adjusted odds ratios (AORs) and 95% confidence intervals (CI).

RESULTS

The study population included 2,474,195 pregnancies. Placental complications (placenta previa, abruptio placenta, and other excessive bleeding) and prematurity were both increased with pregestational and gestational diabetes and hypertension, among subfertile and IVF groups, and in IVF pregnancies using donor oocytes. Both subfertile and IVF pregnancies were at risk for prematurity and NICU admission; IVF infants were also at risk for small-for-gestation birthweight, and subfertile infants had greater risks for neonatal and infant death. Within the IVF group, pregnancies with donor oocytes and/or thawed embryos were at greater risk of large-for-gestation birthweight, and pregnancies with thawed embryos were at greater risk of neonatal and infant death.

CONCLUSIONS

Prematurity was associated with placental complications, diabetes and hypertension, subfertility and IVF groups, and in IVF pregnancies, donor oocytes and/or thawed embryos.