High AMH levels are associated with gestational hypertension in patients with PCOS who underwent IVF/ICSI-ET

BACKGROUND

Patients with polycystic ovary syndrome (PCOS) have a higher risk of obstetric complications. The association between anti-Müllerian hormone (AMH) and gestational hypertension in these patients is poorly understood.

OBJECTIVE

To determine the association between serum AMH levels and gestational hypertension in patients with PCOS undergoing fresh embryo transfer.

METHODS

This retrospective study included 649 patients with PCOS who had singleton live births after undergoing fresh embryo transfers. The association of AMH with gestational hypertension in these patients was estimated before and after propensity score matching (PSM).

RESULTS

Patients with gestational hypertension had higher AMH levels than those without gestational hypertension. In single-factor logistic regression, the odds of gestational hypertension increased by 11.7% and 18.6% for every 1 ng/mL increase in AMH before and after adjusting for confounding factors [OR 1.117, 95% CI(1.025, 1.217), P = 0.012; adjusted OR 1.186, 95% CI(1.061, 1.327), adjusted P = 0.003], respectively. The odds of gestational hypertension increased more than 100% [adjusted OR 2.635, 95% CI(1.132, 6.137), adjusted P = 0.025] in the 75th percentile group (>9.30 ng/ml) and more than thrice [adjusted OR 4.75, 95% CI(1.672, 13.495), adjusted P = 0.003] in the 90th percentile group (>12.31 ng/ml) as compared to the without-gestational hypertension group. AMH level was still associated with gestational hypertension after PSM. The area under the curve of AMH predicting gestational hypertension was 0.654 [95% CI (0.532, 0.776), P = 0.011] with an optimal cutoff value of 11.975 ng/mL.

CONCLUSIONS

High serum AMH level pre-pregnancy (especially at levels > 9.30 ng/mL) indicates a high odds of gestational hypertension in patients with PCOS undergoing fresh embryo transfer.

Does recurrent implantation failure exist? Prevalence and outcomes of five consecutive euploid blastocyst transfers in 123 987 patients

STUDY QUESTION

What are the clinical pregnancy and live birth rates in women who underwent up to two more euploid blastocyst transfers after three failures in the absence of another known factor that affects implantation?

SUMMARY ANSWER

The fourth and fifth euploid blastocyst transfers resulted in similar live birth rates of 40% and 53.3%, respectively, culminating in a cumulative live birth rate of 98.1% (95% CI = 96.5-99.6%) after five euploid blastocyst transfers.

WHAT IS KNOWN ALREADY

The first three euploid blastocysts have similar implantation and live birth rates and provide a cumulative live birth rate of 92.6%.

STUDY DESIGN, SIZE, DURATION

An international multi-center retrospective study was conducted at 25 individual clinics. The study period spanned between January 2012 and December 2022. A total of 123 987 patients with a total of 64 572 euploid blastocyst transfers were screened for inclusion.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Patients with a history of any embryo transfer at another clinic, history of any unscreened embryo transfer at participating clinics, parental karyotype abnormalities, the use of donor oocytes or a gestational carrier, untreated intracavitary uterine pathology (e.g. polyp, leiomyoma), congenital uterine anomalies, adenomyosis, communicating hydrosalpinx, endometrial thickness <6 mm prior to initiating of progesterone, use of testicular sperm due to non-obstructive azoospermia in the male partner, transfer of an embryo with a reported intermediate chromosome copy number (i.e. mosaic), preimplantation genetic testing cycles for monogenic disorders, or structural chromosome rearrangements were excluded. Ovarian stimulation protocols and embryology laboratory procedures including trophectoderm biopsy followed the usual practice of each center. The ploidy status of blastocysts was determined with comprehensive chromosome screening. Endometrial preparation protocols followed the usual practice of participating centers and included programmed cycles, natural or modified natural cycles.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 105 (0.085% of the total population) patients met the criteria and underwent at least one additional euploid blastocyst transfer after failing to achieve a positive pregnancy test with three consecutive euploid blastocyst transfers. Outcomes of the fourth and fifth euploid blastocyst transfers were similar across participating centers. Overall, the live birth rate was similar with the fourth and fifth euploid blastocysts (40% vs 53.3%, relative risk = 1.33, 95% CI = 0.93-1.9, P value = 0.14). Sensitivity analyses excluding blastocysts biopsied on Day 7 postfertilization, women with a BMI >30 kg/m2, cycles using non-ejaculate or donor sperm, double-embryo transfer cycles, and cycles in which the day of embryo transfer was modified due to endometrial receptivity assay test result yielded similar results. Where data were available, the fourth euploid blastocyst had similar live birth rate with the first one (relative risk = 0.84, 95% CI = 0.58-1.21, P = 0.29). The cumulative live birth rate after five euploid blastocyst transfers was 98.1% (95% CI = 96.5-99.6%).

LIMITATIONS, REASONS FOR CAUTION

Retrospective design has its own inherent limitations. Patients continuing with a further euploid embryo transfer and patients dropping out from treatment after three failed euploid transfers can be systematically different, perhaps with regard to ovarian reserve or economic status.

WIDER IMPLICATION OF THE FINDINGS

Implantation failure seems to be mainly due to embryonic factors. Given the stable and high live birth rates up to five euploid blastocysts, unexplained recurrent implantation failure should have a prevalence of <2%. Proceeding with another embryo transfer can be the best next step once a known etiology for implantation failure is ruled out.

STUDY FUNDING/COMPETING INTEREST(S)

None.

TRIAL REGISTRATION NUMBER

N/A.

Association between ambient temperature exposure and pregnancy outcomes in patients undergoing in vitro fertilization in Shanghai, China: a retrospective cohort study

STUDY QUESTION

Does ambient temperature exposure affect outcomes including clinical pregnancy and live birth in women undergoing IVF?

SUMMARY ANSWER

Both extreme cold and hot ambient temperatures were significantly associated with adverse pregnancy outcomes of IVF cycles.

WHAT IS KNOWN ALREADY

Heat exposure has been linked to adverse pregnancy outcomes worldwide. However, the effect of ambient temperature on infertile women undergoing IVF treatment is unclear.

STUDY DESIGN, SIZE, DURATION

A retrospective cohort study was conducted from a database of 3452 infertile women who underwent their first fresh or frozen embryo transfer in the Shanghai First Maternity and Infant Hospital from April 2016 to December 2020.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Daily mean ambient temperature exposure for each patient was obtained based on their residential address. Temperature-stratified multiple logistic regression analysis was performed to investigate associations between temperature exposure and pregnancy outcomes after controlling for confounders. Vulnerable sub-groups were identified using forest plots.

MAIN RESULTS AND THE ROLE OF CHANCE

The clinical pregnancy rate and live birth rate were 45.7% and 37.1%, respectively. Regarding clinical pregnancy, a higher temperature during cold weather was significantly associated with a higher pregnancy rate in the period about 11 weeks before ovarian stimulation (adjusted odds ratio (aOR) = 1.102, 95% CI: 1.012-1.201). Regarding live birth, an increased temperature during cold weather was significantly related to a higher live birth rate in the period after confirmation of clinical pregnancy or biochemical pregnancy, with the aORs of 6.299 (95% CI: 3.949-10.047) or 10.486 (95% CI: 5.609-19.620), respectively. However, a higher temperature during hot weather was negatively associated with the live birth rate in the periods after confirmation of clinical pregnancy or biochemical pregnancy, with the aORs at 0.186 (95% CI: 0.121-0.285) or 0.302 (95% CI: 0.224-0.406), respectively. Moreover, the decline in live birth rates during cold and hot weather was accompanied by increased rates of early miscarriage (P < 0.05). Stratified analyses identified susceptibility characteristics among the participants.

LIMITATIONS, REASONS FOR CAUTION

Climate monitoring data were used to represent individual temperature exposure levels according to the patient's residential address in the study. We were not able to obtain information of personal outdoor activity and use of indoor air conditioners in this retrospective study, which may affect actual temperature exposure.

WIDER IMPLICATIONS OF THE FINDINGS

This study highlights that the ambient temperature exposure should be taken into account during IVF treatment and afterwards. There is a need to be alert to extremes in cold and hot ambient temperatures, especially during the period of follicle development and pregnancy. With this knowledge, clinicians can scientifically determine the timing of IVF treatment and reinforce patients' awareness of self-protection to minimize adverse pregnancy outcomes associated with extreme temperatures.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by a grant from the Clinical Research Plan of Shanghai Hospital Development Center [SHDC2020CR4080], a grant from the Science and Technology Commission of Shanghai Municipality [19411960500], and two grants from the National Natural Science Foundation of China [81871213, 81671468]. B.W.M. is supported by a NHMRC Investigator grant (GNT1176437). B.W.M. reports consultancy for ObsEva, and research grants from Merck KGaA, Ferring and Guerbet. The other authors have no conflict of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

Impact of letrozole co-treatment during ovarian stimulation on oocyte yield, embryo development, and live birth rate in women with normal ovarian reserve: secondary outcomes from the RIOT trial

STUDY QUESTION

Does letrozole (LZ) co-treatment during ovarian stimulation with gonadotropins for in IVF impact follicle recruitment, oocyte number and quality, embryo quality, or live birth rate (LBR)?

SUMMARY ANSWER

No impact of LZ was found in follicle recruitment, number of oocytes, quality of embryos, or LBR.

WHAT IS KNOWN ALREADY

Multi-follicle stimulation for IVF produces supra-physiological oestradiol levels. LZ is an aromatase inhibitor that lowers serum oestradiol thus reducing negative feedback and increasing the endogenous gonadotropins in both the follicular and the luteal phases, effectively normalizing the endocrine milieu during IVF treatment.

STUDY DESIGN, SIZE, DURATION

Secondary outcomes from a randomized, double-blind placebo-controlled trial (RCT) investigating once-daily 5 mg LZ or placebo during stimulation for IVF with FSH. The RCT was conducted at four fertility clinics at University Hospitals in Denmark from August 2016 to November 2018 and pregnancy outcomes of frozen-thawed embryo transfers (FET) registered until May 2023.

PARTICIPANTS/MATERIALS, SETTING, METHODS

One hundred fifty-nine women with expected normal ovarian reserve (anti-Müllerian hormone 8-32 nmol/l) were randomized to either co-treatment with LZ (n = 80) or placebo (n = 79). In total 1268 oocytes were aspirated developing into 386 embryos, and morphology and morphokinetics were assessed. One hundred twenty-nine embryos were transferred in the fresh cycle and 158 embryos in a subsequent FET cycle. The effect of LZ on cumulative clinical pregnancy rate (CPR), LBR, endometrial thickness in the fresh cycle, and total FSH consumption was reported.

MAIN RESULTS AND THE ROLE OF CHANCE

The proportion of usable embryos of retrieved oocytes was similar in the LZ group and the placebo group with 0.31 vs 0.36 (mean difference (MD) -0.05, 95% CI (-0.12; 0.03), P = 0.65). The size and number of aspirated follicles at oocyte retrieval were similar with 11.8 vs 10.3 follicles per patient (MD 1.5, 95% CI (-0.5; 3.1), P = 0.50), as well as the number of retrieved oocytes with 8.0 vs 7.9 oocytes (MD 0.1, 95% CI (-1.4; 1.6), P = 0.39) in the LZ and placebo groups, respectively. The chance of retrieving an oocyte from the 13 to 16 mm follicles at trigger day was 66% higher (95% CI (24%; 108%), P = 0.002) in the placebo group than in the LZ group, whilst the chance of retrieving an oocyte from the ≥17 mm follicles at trigger day was 50% higher (95% CI (2%; 98%), P = 0.04) in the LZ group than in the placebo group. The proportion of fertilized oocytes with two-pronuclei per retrieved oocytes or per metaphase II oocytes (MII) (the 2PN rates) were similar regardless of fertilization with IVF or ICSI with 0.48 vs 0.57 (MD -0.09, 95% CI (-0.24; 0.04), P = 0.51), and 0.62 vs 0.64 (MD -0.02, 95% CI (-0.13; 0.07), P = 0.78) in the LZ and placebo groups, respectively. However, the MII rate in the ICSI group was significantly lower with 0.75 vs 0.88 in the LZ vs the placebo group (MD -0.14, 95% CI (-0.22; -0.06), P = 0.03). Blastocysts on Day 5 per patient were similar with 1.5 vs 2.0, P = 0.52, as well as vitrified blastocysts per patient Day 5 with 0.8 vs 1.2 in (MD -0.4, 95% CI (-1.0; 0.2), P = 0.52) and vitrified blastocysts per patient Day 6 with 0.6 vs 0.6 (MD 0, 95% CI (-0.3; 0.3), P = 1.00) in the LZ vs placebo group, respectively. Morphologic evaluation of all usable embryos showed a similar distribution in 'Good', 'Fair', and 'Poor', in the LZ vs placebo group, with an odds ratio (OR) of 0.8 95% CI (0.5; 1.3), P = 0.68 of developing a better class embryo. Two hundred and ninety-five of the 386 embryos were cultured in an embryoscope. Morphokinetic annotations showed that the odds of having a high KIDscore™ D3 Day 3 were 1.2 times higher (CI (0.8; 1.9), P = 0.68) in the LZ group vs the placebo group. The CPR per transfer was comparable with 31% vs 39% (risk-difference of 8%, 95% CI (-25%; 11%), P = 0.65) in the LZ and placebo group, respectively, as well as CPR per transfer adjusted for day of transfer, oestradiol and progesterone levels at trigger, progesterone levels mid-luteal, and number of oocytes retrieved (adjusted OR) of 0.8 (95% CI (0.4; 1.6), P = 0.72). Comparable LBR were found per transfer 28% vs 37% (MD -9%, 95% CI (-26%; 9%), P = 0.60) and per randomized women 24% vs 30% (MD of -6%, CI (-22%; 8%), P = 0.60) in the LZ group and placebo group, respectively. Furthermore, 4.8 years since the last oocyte aspiration, a total of 287 of 386 embryos have been transferred in the fresh or a subsequently FET cycle, disclosing the cumulative CPR, which is similar with 38% vs 34% (MD 95% CI (8%; 16%), P = 0.70) in the LZ vs placebo group.

LIMITATIONS, REASONS FOR CAUTION

Both cleavage stage and blastocyst transfer and vitrification were permitted in the protocol, making it necessary to categorize their quality and pool the results. The study was powered to detect hormonal variation but not embryo or pregnancy outcomes.

WIDER IMPLICATIONS OF THE FINDINGS

The similar utilization rate and quality of the embryos support the use of LZ co-treatment for IVF with specific indication as fertility preservation, patients with previous cancer, or poor responders. The effect of LZ on mature oocytes from different follicle sizes and LBRs should be evaluated in a meta-analysis or a larger RCT.

STUDY FUNDING/COMPETING INTEREST(S)

Funding was received from EU Interreg for ReproUnion, Sjaelland University Hospital, Denmark, Ferring Pharmaceuticals, and Gedeon Ricther. Roche Diagnostics contributed with assays. A.P. has received grants from Ferring, Merck Serono, and Gedeon Richter, consulting fees from Preglem, Novo Nordisk, Ferring, Gedeon Richter, Cryos, & Merck A/S, speakers fees from Gedeon Richter, Ferring, Merck A/S, Theramex, & Organon, and travel support from Gedeon Richter. The remaining authors declare that they have no competing interests in the research or publication.

TRIAL REGISTRATION NUMBERS

NCT02939898 and NCT02946684.

Personalized embryo transfer reduces success rates because endometrial receptivity analysis fails to accurately identify the window of implantation

After more than a decade of increasingly widespread clinical use, personalized embryo transfer guided by endometrial receptivity analysis (ERA) remains controversial and unproven. One key element missing from the historical literature is the recognition that potential benefits from personalized embryo transfer are entirely dependent on the accuracy and predictive value of the ERA test. Results from the first comprehensive clinical trial, designed in a way that allowed independent evaluation of both potential benefits of personalized embryo transfer and the predictive value of the ERA test upon which it is based, were recently published. However, the authors failed to conduct an appropriate analysis or recognize the significance of their results. Here, we present a simple reanalysis of data from this otherwise excellent randomized controlled trial, demonstrating for the first time that the ERA was unable to identify the window of implantation as purported and that, as a result, personalized embryo transfer based on the ERA actually reduced rather than increased the birth rates. Based on these results and the lack of any contradictory evidence, it is our opinion that all clinical use of ERA-guided personalized embryo transfer should be discontinued immediately, outside of a controlled experimental setting with appropriate informed consent of all participating patients.

50 years of sperm cell isolations: from structural to omic studies

The fusion of male and female gametes is a fundamental process in the perpetuation and diversification of species. During the last 50 years, significant efforts have been made to isolate and characterize sperm cells from flowering plants, and to identify how these cells interact with female gametes to achieve double fertilization. The first techniques and analytical approaches not only provided structural and biochemical characterizations of plant sperm cells but also paved the way for in vitro fertilization studies. Further technological advances then led to unique insights into sperm biology at transcriptomic, proteomic and epigenetic level. Starting with a historical overview of sperm cell isolation techniques, we provide examples of how these contributed to create our current knowledge of sperm cell biology, and point out remaining challenges.

Circulating maternal prorenin and oocyte and preimplantation embryo development: the Rotterdam Periconception Cohort

STUDY QUESTION

Could circulating maternal prorenin serve as a proxy for oocyte and preimplantation embryo development, assessed by time-lapse parameters and clinical treatment outcomes?

SUMMARY ANSWER

High circulating maternal prorenin concentrations after ovarian stimulation associate with a larger oocyte area, faster cleavage divisions from the five-cell stage onwards and increased chance of successful implantation.

WHAT IS KNOWN ALREADY

After ovarian stimulation, circulating prorenin (renin's precursor), is largely ovary-derived. Prorenin may contribute to ovarian angiotensin synthesis, which is relevant in reproduction given its role in follicular development and oocyte maturation.

STUDY DESIGN, SIZE, DURATION

Prospective observational cohort study including couples requiring fertility treatment from May 2017 as a subcohort of the ongoing Rotterdam Periconception Cohort conducted in a tertiary referral hospital.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Between May 2017 and July 2020, 309 couples with an indication for IVF treatment or ICSI were included. Resulting embryos (n = 1024) were submitted to time-lapse embryo culture. Time of fertilization (t0), pronuclear appearance (tPNa), and fading (tPNf) as well as the exact timing of reaching the two- to eight-cell stage (t2-t8), the start of blastulation (tSB), reaching the full (tB), and expanded blastocyst (tEB) were retrospectively recorded. Oocyte area was measured at t0, tPNa, and tPNf. Prorenin was determined at the day of embryo transfer.

MAIN RESULTS AND THE ROLE OF CHANCE

After adjustment for patient- and treatment-related factors, linear mixed modeling showed that higher prorenin concentrations associate with a larger oocyte area at tPNa (β 64.45 µm2, 95% CI 3.26; 125.64, P = 0.04), and faster progression from five-cell stage onwards (e.g. β8-cell -1.37 h, 95% CI -2.48; -0.26, P = 0.02). Prorenin associated positively with pre-transfer outcomes (e.g. βfertilized oocytes 2.09, 95% CI 1.43; 2.75, P < 0.001) and implantation (odds ratio+β-hCG-test: 1.79, 95% CI 1.06; 3.08, P = 0.03), but not with live birth.

LIMITATIONS, REASONS FOR CAUTION

This prospective observational study provides associations and therefore residual confounding cannot be excluded and causality has to be shown in intervention studies.

WIDER IMPLICATIONS OF THE FINDINGS

Theca cell-derived factors, such as prorenin, may help to clarify the underlying endocrine mechanism of oocyte maturation and embryo development, with a special focus on the (patho)physiological reproductive role of prorenin and the identification of factors influencing its secretion and activity, which is of great added value for improving embryo selection and predicting implantation and pregnancy outcomes. This will bring us to investigate which determinants of oocyte quality and embryo development should take center stage in developing preconception care strategies.

STUDY FUNDING/COMPETING INTEREST(S)

This research was funded by the Department of Obstetrics and Gynecology of the Erasmus MC, University Medical Center, Rotterdam, the Netherlands, and the Erasmus MC Medical Research Advisor Committee's 'Health Care Efficiency Research' program (OZBS72.16080). The authors have no competing interests to disclose.

TRIAL REGISTRATION NUMBER

N/A.

Preimplantation genetic testing and child health: a national register-based study

STUDY QUESTION

Is preimplantation genetic testing (PGT) associated with adverse perinatal outcome and early childhood health?

SUMMARY ANSWER

Children born after PGT had comparable perinatal outcomes to children born after IVF/ICSI and comparable findings regarding early childhood health.

WHAT IS KNOWN ALREADY

PGT is offered to couples affected by monogenic disorders (PGT-M) or inherited chromosomal aberrations (PGT-SR), limiting the risk of transferring the disorder to the offspring. PGT, an invasive technique, requires genetic analysis of one or up to ten cells from the embryo and is combined with IVF or ICSI. Several studies, most of them small, have shown comparable results after PGT and IVF/ICSI concerning perinatal outcome. Only a few studies with limited samples have been published on PGT and childhood health.

STUDY DESIGN, SIZE, DURATION

We performed a register-based study including all singletons born after PGT (n = 390) in Sweden during 1 January 1996-30 September 2019. Singletons born after PGT were compared with all singletons born after IVF/ICSI (n = 61 060) born during the same period of time and with a matched sample of singletons (n = 42 034) born after spontaneous conception selected from the Medical Birth Register. Perinatal outcomes, early childhood health, and maternal outcomes were compared between pregnancies after PGT and IVF/ICSI as well as between pregnancies after PGT and spontaneous conception. Primary outcomes were preterm birth (PTB) and low birthweight (LBW) whereas childhood morbidity was the secondary outcome.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Data on women who went through PGT and gave birth were obtained from the local databases at the two PGT centres in Sweden, whereas data on IVF treatment for the IVF/ICSI group were obtained from the national IVF registers. These data were then cross-linked to national health registers; the Medical Birth Register, the Patient Register, and the Cause of Death Register. Logistic multivariable regression analysis and Cox proportional hazards models were performed with adjustment for relevant confounders.

MAIN RESULTS AND THE ROLE OF CHANCE

The mean follow-up time was 4.6 years for children born after PGT and 5.1 years for children born after spontaneous conception, whereas the mean follow-up time was 9.0 years for children born after IVF/ICSI. For perinatal outcomes, PTB occurred in 7.7% of children after PGT and in 7.3% of children after IVF/ICSI, whereas the rates were 4.9% and 5.2% for LBW (adjusted odds ratio (AOR) 1.22, 95% CI 0.82-1.81 and AOR 1.17, 95% CI 0.71-1.91, respectively). No differences were observed for birth defects. In comparison to spontaneous conception, children born after PGT had a higher risk for PTB (AOR 1.73, 95% CI 1.17-2.58). Regarding early childhood health, the absolute risk of asthma was 38/390 (9.7%) in children born after PGT and 6980/61 060 (11.4%) in children born after in IVF/ICSI, whereas the corresponding numbers were 34/390 (8.7%) and 7505/61 060 (12.3%) for allergic disorders. Following Cox proportional hazards models, no significant differences were found for these outcomes. Sepsis, hypothyroidism, attention deficit hyperactivity disorder, autism spectrum disorders, mental retardation, cerebral palsy, and epilepsy were diagnosed in a maximum of three PGT children. No PGT children died during the follow-up period. Regarding maternal outcomes, the rates of placenta praevia and caesarean delivery were significantly higher after PGT in comparison to spontaneous conception (AOR 6.46, 95% CI 3.38-12.37 and AOR 1.52, 95% CI 1.20-1.92, respectively), whereas no differences were seen comparing pregnancies after PGT and IVF/ICSI.

LIMITATIONS, REASONS FOR CAUTION

The rather small sample size of children born after PGT made it impossible to adjust for all relevant confounders including fertilization method and culture duration. Moreover, the follow-up time was short for most of the children especially in the PGT group, probably lowering the absolute number of diagnoses in early childhood.

WIDER IMPLICATIONS OF THE FINDINGS

The results are reassuring and indicate that the embryo biopsy itself has no adverse effect on the perinatal, early childhood, or maternal outcomes. Although the results are comparable to IVF/ICSI also regarding early childhood outcome, they should be taken with caution due to the low number of children with diagnoses and short follow-up time. Long-term follow-up studies on children born after PGT are scarce and should be conducted considering the invasiveness of the technique.

STUDY FUNDING/COMPETING INTEREST(S)

The study was financed by grants from the Swedish state under the agreement between the Swedish government and the county councils, the ALF-agreement (LUA/ALF 70940), the Board of National Specialised Medical Care at Sahlgrenska University Hospital and Hjalmar Svensson Research Foundation. There are no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

Preconception paternal alcohol exposure decreases IVF embryo survival and pregnancy success rates in a mouse model

Increasingly, couples struggling with fertility turn to assisted reproductive techniques, including IVF, to have children. Despite the demonstrated influence of periconception male health and lifestyle choices on offspring development, studies examining IVF success rates and child health outcomes remain exclusively focused on maternal factors. Using a physiologically relevant mouse model, we tested the hypothesis that chronic paternal preconception alcohol intake adversely affects IVF success and negatively impacts IVF offspring fetoplacental growth. Using a voluntary, binge-like mouse model, we exposed sexually mature C57BL/6J males to three preconception treatments (0% (Control), 6% EtOH or 10% EtOH) for 6 weeks, isolated and cryopreserved caudal sperm from treated males, and then used these samples to fertilize oocytes before assessing IVF embryo developmental outcomes. We found that preconception paternal alcohol use reduced IVF embryo survival and pregnancy success rates in a dose-dependent manner, with the pregnancy success rate of the 10% EtOH treatment falling to half those of the Controls. Mechanistically, we found that preconception paternal alcohol exposure disrupts embryonic gene expression, including Fgf4 and Egfr, two critical regulators of trophectoderm stem cell growth and placental patterning, with lasting impacts on the histological organization of the late-term placenta. The changes in placental histoarchitecture were accompanied by altered regulation of pathways controlling mitochondrial function, oxidative phosphorylation and some imprinted genes. Our studies indicate that male alcohol use may significantly impede IVF success rates, increasing the couple's financial burden and emotional stress, and highlights the need to expand prepregnancy messaging to emphasize the reproductive dangers of alcohol use by both parents.

Associations between epigenetic age acceleration and infertility

STUDY QUESTION

Is the use of ART, a proxy for infertility, associated with epigenetic age acceleration?

SUMMARY ANSWER

The epigenetic age acceleration measured by Dunedin Pace of Aging methylation (DunedinPoAm) differed significantly between non-ART and ART mothers.

WHAT IS KNOWN ALREADY

Among mothers who used ART, epigenetic age acceleration may be associated with low oocyte yield and poor ovarian response. However, the difference in epigenetic age acceleration between non-ART and ART mothers (or even fathers) has not been examined.

STUDY DESIGN, SIZE, DURATION

The Norwegian Mother, Father and Child Cohort Study (MoBa) recruited pregnant women and their partners across Norway at around 18 gestational weeks between 1999 and 2008. Approximately 95 000 mothers, 75 000 fathers and 114 000 children were included. Peripheral blood samples were taken from mothers and fathers at ultrasound appointments or from mothers at childbirth, and umbilical cord blood samples were collected from the newborns at birth.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Among the MoBa participants, we selected 1000 couples who conceived by coitus and 894 couples who conceived by IVF (n = 525) or ICSI (n = 369). We measured their DNA methylation (DNAm) levels using the Illumina MethylationEPIC array and calculated epigenetic age acceleration. A linear mixed model was used to examine the differences in five different epigenetic age accelerations between non-ART and ART parents.

MAIN RESULTS AND THE ROLE OF CHANCE

We found a significant difference in the epigenetic age acceleration calculated by DunedinPoAm between IVF and non-ART mothers (0.021 years, P-value = 2.89E−06) after adjustment for potential confounders. Further, we detected elevated DunedinPoAm in mothers with tubal factor infertility (0.030 years, P-value = 1.34E−05), ovulation factor (0.023 years, P-value = 0.0018) and unexplained infertility (0.023 years, P-value = 1.39E−04) compared with non-ART mothers. No differences in epigenetic age accelerations between non-ART and ICSI fathers were found. DunedinPoAm also showed stronger associations with smoking, education and parity than the other four epigenetic age accelerations.

LIMITATIONS, REASONS FOR CAUTION

We were not able to determine the directionality of the causal pathway between the epigenetic age accelerations and infertility. Since parents’ peripheral blood samples were collected after conception, we cannot rule out the possibility that the epigenetic profile of ART mothers was influenced by the ART treatment. Hence, the results should be interpreted with caution, and our results might not be generalizable to non-pregnant women.

WIDER IMPLICATIONS OF THE FINDINGS

A plausible biological mechanism behind the reported association is that IVF mothers could be closer to menopause than non-ART mothers. The pace of decline of the ovarian reserve that eventually leads to menopause varies between females yet, in general, accelerates after the age of 30, and some studies show an increased risk of infertility in females with low ovarian reserve.

STUDY FUNDING/COMPETING INTEREST(S)

This study was partly funded by the Research Council of Norway (Women’s fertility, project no. 320656) and through its Centres of Excellence Funding Scheme (project no. 262700). M.C.M. has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement number 947684). The authors declare no conflict of interest.

TRIAL REGISTRATION NUMBER

N/A.

Administration of growth hormone improves endometrial function in women undergoing in vitro fertilization: a systematic review and meta-analysis

BACKGROUND

The positive effects of growth hormone (GH) on IVF are often attributed to improvements in oocyte and embryo quality. While emerging evidence emphasizes GH-induced improvements in the endometrium, these results are controversial.

OBJECTIVE AND RATIONALE

This meta-analysis aimed to evaluate whether GH administration improved endometrial function and reproductive outcomes during IVF cycles and to thus guide clinical practice.

SEARCH METHODS

A literature search in the Cochrane Central Register of Controlled Trials, PubMed and Embase was performed through to 30 November 2021, without language restrictions. Randomized controlled trials (RCTs) evaluating the effects of GH on IVF outcomes were included. Risk of bias and quality of evidence (QoE) were assessed according to the Cochrane Collaboration's tool and the Grading of Recommendations Assessment, Development and Evaluation system. Odds ratios (ORs) and mean differences (MDs) with 95% confidence intervals (CIs) were assessed by random-effects models.

OUTCOMES

A total of 25 trials with 2424 women were included. Seventeen RCTs with poor responders (n = 1723) showed that GH administration significantly increased endometrial thickness (EMT) (MD = 0.38, 95% CI: 0.18-0.59; moderate QoE), which contributed to an improved live birth rate (OR = 1.67, 95% CI: 1.13-2.49; very low QoE) and clinical pregnancy rate (CPR) (OR = 1.97, 95% CI: 1.43-2.72; low QoE). Subgroup analyses showed a dose- and time-dependent relationship between GH cotreatment and IVF outcomes; the optimal recommendation for improving CPR was consistent with that for EMT, rather than for oocytes and embryos. Hence, GH might improve fertility via effects on the endometrium. Administration of GH daily from the follicular phase of previous cycle until the hCG trigger with < 5 IU/day led to a thicker endometrium and a greater chance of becoming pregnant, while 5-10 IU/day or administration from the luteal phase of the previous cycle until the hCG trigger resulted in higher oocyte and embryo quality. Poor responders might benefit from cotreatment with the GnRH agonist long protocol more than other stimulation protocols. Pooled data from four trials (n = 354) on women with a thin endometrium indicated that improved endometrial function might be critical for improving reproductive outcomes during GH treatment, as no improvements in embryo quality were found. GH administration not only increased EMT (MD = 1.48, 95% CI: 1.21-1.75; moderate QoE) but also promoted endometrial morphology (OR = 2.67, 95% CI: 1.36-5.23; low QoE) and perfusion (OR = 5.84, 95% CI: 1.30-26.17; low QoE), thereby improving the CPR (OR = 2.71, 95% CI: 1.69-4.34; P < 0.0001; low QoE). There was insufficient evidence to reach a conclusion regarding the effects of GH in normal responders (n = 80). Due to obvious improvements in the CPR, women with a thin endometrium might be the most appropriate population to benefit from GH administration.

WIDER IMPLICATIONS

Improving endometrial function might be another vital mechanism by which GH improves IVF outcomes. Optimal treatment should be offered to the target population according to their personal conditions and needs. The QoE was moderate to very low, due to limited sample sizes and methodological problems; thus, the results should be interpreted with caution. More rigorous RCTs with large sample sizes are needed to confirm the effects and determine optimal GH protocols.

In vitro maturation without gonadotropins versus in vitro fertilization with hyperstimulation in women with polycystic ovary syndrome: a non-inferiority randomized controlled trial

STUDY QUESTION

Does in vitro maturation (IVM) result in non-inferior cumulative live birth rates compared to those after standard in vitro fertilization (IVF) in infertile women with polycystic ovary syndrome (PCOS)?

SUMMARY ANSWER

One cycle of IVM, without any stimulation, was inferior to one cycle of standard IVF in women with PCOS in terms of 6-month cumulative live birth rates, when choosing single vitrified-warmed blastocyst transfer.

WHAT IS KNOWN ALREADY

IVM is an emerging alternative treatment for women with PCOS who need assisted reproductive technology. Since a minimal or even zero dose of gonadotropins are required in the IVM procedure, the occurrence of ovarian hyperstimulation syndrome (OHSS) is eliminated. Only one clinical trial comparing the pregnancy outcome between IVM with FSH priming and IVF has been reported. However, it is still unknown whether IVM treatment without any stimulation can offer a similar live birth outcome in women with PCOS as compared to that in women receiving the standard IVF procedure with ovarian stimulation.

STUDY DESIGN, SIZE, DURATION

This single-centre, open-label randomized controlled non-inferiority trial in an academic infertility centre in China was performed between March 2018 and July 2019.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Women aged 20-38 years with PCOS and infertility scheduled for their first IVF attempt were eligible. In total, 351 women were randomly allocated to receive one cycle of unstimulated IVM (n = 175) or one cycle of standard IVF with a flexible GnRH antagonist protocol and hCG as ovulatory trigger (n = 176). A freeze-all and single blastocyst transfer strategy was used in both groups. The primary outcome was ongoing pregnancy (leading to live birth) within 6 months after randomization. A non-inferiority margin of 15% was considered.

MAIN RESULTS AND THE ROLE OF CHANCE

The IVM procedure without additional gonadotropin resulted in a lower ongoing pregnancy (leading to live birth) within 6 months after randomization compared to standard IVF treatment (22.3% vs. 50.6%; rate difference -28.3%; 95% confidence interval [CI]: -37.9% to -18.7%). Moderate-severe OHSS did not occur in the IVM group, while in the IVF group, ten women (5.7%) had moderate OHSS and one woman (0.6%) had severe OHSS. There was no statistically significant difference in the occurrence of obstetric and perinatal complications.

LIMITATIONS, REASONS FOR CAUTION

The trial was conducted using an IVM protocol without additional stimulation in a single centre, which may limit its generalizability. In addition, a GnRH agonist trigger rather than hCG for IVF stimulation in women with PCOS would be more consistent with current clinical practice.

WIDER IMPLICATIONS OF THE FINDINGS

Although IVM is considered to be a convenient, inexpensive and safe alternative to IVF for women with PCOS, our results indicated that one cycle of IVM without any stimulation was inferior to one cycle of standard IVF in terms of the cumulative live birth rate. The inferiority of IVM without ovarian stimulation could be mainly due to the limitations in the developmental potential of embryos. Further IVM development should be tested and validated in a freeze-only and blastocyst transfer setting. Further RCTs are needed to evaluate the effectiveness and safety of other IVM protocols or multiple cycles of IVM compared to IVF.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by the National Key Research and Development Program of China (2016YFC1000201 and 2018YFC1002104) and the National Science Foundation of China (81730038). B.W.M. is supported by a NHMRC Investigator grant (GNT1176437). All other authors declare no competing interests.

TRIAL REGISTRATION NUMBER

Clinicaltrials.gov NCT03463772.

TRIAL REGISTRATION DATE

29 January 2018.

DATE OF FIRST PATIENT’S ENROLMENT

16 March 2018.

Ovarian stimulation for fertility treatments and risk of breast cancer: a matched cohort study

STUDY QUESTION

Is there a difference in the breast cancer risk among women who underwent ART treatments compared to those who underwent medically assisted reproduction (MAR) infertility treatments or women of reproductive age in the general population?

SUMMARY ANSWER

The risk of breast cancer among women treated by ART was similar to the risk among women treated by MAR and women who did not undergo fertility treatments.

WHAT IS KNOWN ALREADY

Studies investigating breast cancer risk in women who have undergone fertility treatments have provided conflicting results.

STUDY DESIGN, SIZE, DURATION

A retrospective, population-based cohort study included women who underwent ART or MAR treatments and women who did not undergo fertility treatments from 1994 to 2019.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Women who underwent ART were matched one to one with women who underwent MAR treatments and one to one with woman from the general population of reproductive age, by year of birth and year of first delivery or nulliparity status. MAR women were also matched to ART women by treatment initiation calendar year. All included women were members of Maccabi Healthcare Services. Data regarding demographics, fertility treatments, BRCA mutation and possible confounders were obtained from the computerized database of electronic health records. The incidence of breast cancer after fertility treatments was compared to the matched controls.

MAIN RESULTS AND THE ROLE OF CHANCE

Of 8 25 721 women of reproductive age, 32 366 women who underwent ART were matched with patients treated by MAR (n = 32 366) and 32 366 women of reproductive age. A total of 984 women (1.0%) were diagnosed with breast cancer (mean follow-up period, 9.1 ± 6.3 years; interquartile range [IQR], 3.8-13.7 years). The incidence rates of breast cancer per 10 000 person-years were 11.9 (95% CI, 10.7-13.3), 10.7 (95% CI, 9.6-11.9) and 10.7 (95% CI, 9.6-12.0) in the ART group, MAR group and general population, respectively. The crude risk for breast cancer was similar in the ART group compared with the general population (hazard ratio (HR) = 1.10, 95% CI, 0.94-1.28) and in the ART group compared with the MAR group (HR = 1.00, 95% CI, 0.86-1.16). Further adjustment for age, BMI, smoking, socioeconomic status and parity did not substantially impact the hazard rates for breast cancer (ART vs general population: HR = 1.10, 95% CI, 0.94-1.28; ART vs MAR: HR = 0.99, 95% CI, 0.85-1.16). Among women diagnosed with breast cancer, the prevalence of BRCA1/2 mutations and tumour staging did not differ between the ART, MAR and general population groups. Among women who underwent ART, no correlation was found between breast cancer and the number of ART cycles or the use of recombinant medications or urine-derived medications.

LIMITATIONS, REASONS FOR CAUTION

The mean age of women at the end of follow-up was only 42 years thus the study was not powered to detect potential differences in the risk of postmenopausal breast cancer. In addition, we did not sub-classify the exposed patients by the reason for infertility.

WIDER IMPLICATIONS OF THE FINDINGS

Breast cancer incidence following ART was comparable to that in the general population or following MAR. Women undergoing fertility treatments and their clinicians may be reassured about the safety of assisted reproduction technologies in terms of premenopausal breast cancer risk.

STUDY FUNDING/COMPETING INTEREST(S)

No specific funding was used and there are no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

Impact of letrozole co-treatment during ovarian stimulation with gonadotrophins for IVF: a multicentre, randomized, double-blinded placebo-controlled trial

STUDY QUESTION

Does letrozole co-treatment during ovarian stimulation with gonadotrophins for IVF reduce the proportion of women with premature progesterone levels above 1.5 ng/ml at the time of triggering final oocyte maturation?

SUMMARY ANSWER

The proportion of women with premature progesterone above 1.5 ng/ml was not significantly affected by letrozole co-treatment.

WHAT IS KNOWN ALREADY

IVF creates multiple follicles with supraphysiological levels of sex steroids interrupting the endocrine milieu and affects the window of implantation. Letrozole is an effective aromatase inhibitor, normalizing serum oestradiol, thereby ameliorating some of the detrimental effects of IVF treatment.

STUDY DESIGN, SIZE, DURATION

A randomized, double-blinded placebo-controlled trial investigated letrozole intervention during stimulation for IVF with FSH. The trial was conducted at four fertility clinics at University Hospitals in Denmark from August 2016 to November 2018.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A cohort of 129 women with expected normal ovarian reserve (anti-Müllerian hormone 8-32 nmol/l) completed an IVF cycle with fresh embryo transfer and received co-treatment with either 5 mg/day letrozole (n = 67) or placebo (n = 62), along with the FSH. Progesterone, oestradiol, FSH, LH and androgens were analysed in repeated serum samples collected from the start of the stimulation to the mid-luteal phase. In addition, the effect of letrozole on reproductive outcomes, total FSH consumption and adverse events were assessed.

MAIN RESULTS AND THE ROLE OF CHANCE

The proportion of women with premature progesterone >1.5 ng/ml was similar (6% vs 0% (OR 0.0, 95% CI [0.0; 1.6], P = 0.12) in the letrozole versus placebo groups, respectively), whereas the proportion of women with mid-luteal progesterone >30 ng/ml was significantly increased in the letrozole group: (59% vs 31% (OR 3.3, 95% CI [1.4; 7.1], P = 0.005)). Letrozole versus placebo decreased oestradiol levels on the ovulation trigger day by 68% (95% CI [60%; 75%], P < 0.0001). Other hormonal profiles, measured as AUC, showed the following results. The increase in LH in the letrozole group versus placebo group was 38% (95% CI [21%; 58%], P < 0.0001) and 34% (95% CI [11%; 61%], P = 0.006) in the follicular and luteal phases, respectively. In the letrozole group versus placebo group, testosterone increased by 79% (95% CI [55%; 105%], P < 0.0001) and 49% (95% CI [30%; 72%], P < 0.0001) in the follicular and luteal phases, respectively. In the letrozole group versus placebo group, the increase in androstenedione was by 85% (95% CI [59%; 114%], P < 0.0001) and 69% (95% CI [48%; 94%], P < 0.0001) in the follicular and luteal phases, respectively. The ongoing pregnancy rate was similar between the letrozole and placebo groups (31% vs 39% (risk-difference of 8%, 95% CI [-25%; 11%], P = 0.55)). No serious adverse reactions were recorded in either group. The total duration of exogenous FSH stimulation was 1 day shorter in the intervention group, significantly reducing total FSH consumption (mean difference -100 IU, 95% CI [-192; -21], P = 0.03).

LIMITATIONS, REASONS FOR CAUTION

Late follicular progesterone samples were collected on the day before and day of ovulation triggering for patient logistic considerations, and the recently emerged knowledge about diurnal variation of progesterone was not taken into account. The study was powered to detect hormonal variations but not differences in pregnancy outcomes.

WIDER IMPLICATIONS OF THE FINDINGS

Although the use of letrozole has no effect on the primary outcome, the number of women with a premature increase in progesterone on the day of ovulation triggering, the increased progesterone in the mid-luteal phase due to letrozole may contribute to optimizing the luteal phase endocrinology. The effect of letrozole on increasing androgens and reducing FSH consumption may be used in poor responders. However, the effect of letrozole on implantation and ongoing pregnancy rates should be evaluated in a meta-analysis or larger randomized controlled trial (RCT).

STUDY FUNDING/COMPETING INTEREST(S)

Funding was received from EU Interreg for ReproUnion and Ferring Pharmaceuticals, and Roche Diagnostics contributed with assays. N.S.M. and A.P. have received grants from Ferring, Merck Serono, Anecova and Gedeon Richter, and/or personal fees from IBSA, Vivoplex, ArtPred and SPD, outside the submitted work. The remaining authors have no competing interests.

TRIAL REGISTRATION NUMBERS

NCT02939898 and NCT02946684.

TRIAL REGISTRATION DATE

15 August 2016.

DATE OF FIRST PATIENT’S ENROLMENT

22 August 2016.

The role of protein arginine methyltransferase 7 in human developmentally arrested embryos cultured in vitro

Human embryos of in vitro fertilization (IVF) are often susceptible to developmental arrest, which greatly reduces the efficiency of IVF treatment. In recent years, it has been found that protein arginine methyltransferase 7 (PRMT7) plays an important role in the process of early embryonic development. However, not much is known about the relationship between PRMT7 and developmentally arrested embryos. The role of PRMT7 in developmentally arrested embryos was thus investigated in this study. Discarded human embryos from IVF were collected for experimental materials. Quantitative real-time polymerase chain reaction (qRT-PCR) and confocal analyses were used to identify PRMT7 mRNA and protein levels in early embryos at different developmental stages, as well as changes in the methylation levels of H4R3me2s. Additionally, PRMT7 was knocked down in the developmentally arrested embryos to observe the further development of these embryos. Our results demonstrated that PRMT7 mRNA and protein levels in arrested embryos were significantly increased compared with those in control embryos; meanwhile, the methylation levels of H4R3me2s in arrested embryos were also increased significantly. Knockdown of PRMT7 could rescue partially developmentally arrested embryos, and even individual developmentally arrested embryos could develop into blastocysts. In conclusion, over-expression of PRMT7 disrupts the early embryo development process, leading to early embryos developmental arrest, but these developmentally arrested defects could be partially rescued by knockdown of the PRMT7 protein.