Ovarian reserve does not influence natural conception: insights from infertile women.

PURPOSE: There is several albeit not univocal evidence suggesting that ovarian reserve is not related to the chance of natural pregnancy, provided that the remnant follicular pool is sufficient to ensure regular menstrual cycles. Nevertheless, available studies have some methodological limitations, and the issue cannot be considered definitively ascertained. METHODS: To further address this issue, we retrospectively selected infertile women whose infertility diagnostic work-up was unremarkable (unexplained infertility-cases) and matched them by age and study period to a group of infertile women who were diagnosed with severe male infertility (controls). If ovarian reserve impacts on natural fertility, one had to expect lower ovarian reserve among women with unexplained infertility. Tested biomarkers included AMH, AFC and day 2-3 serum FSH. The primary aim was the frequency of women with serum AMH < 0.7 ng/ml. RESULTS: Two-hundred fifty-two women with unexplained infertility and 252 women with male infertility were included. All biomarkers of ovarian reserve did not differ between the study groups. AMH levels < 0.7 ng/mL were observed in 26 (10%) women with unexplained infertility and 35 (14%) women with male infertility (p = 0.28). The adjusted OR was 0.76 (95% CI: 0.44-1.33). Significant differences did not also emerge when repeating this dichotomous analysis using other biomarkers and other thresholds for the definition of low-ovarian reserve. CONCLUSION: This study confirms that ovarian reserve is unremarkable to natural conception. Physicians and patients should be aware of this concept to avoid inappropriate counseling and undue clinical decisions.

Unexplained infertility and age-related infertility: indistinguishable diagnostic entities but different IVF prognosis.

STUDY QUESTION: Is IVF indicated for couples with age-related infertility? SUMMARY ANSWER: IVF may be of doubtful utility for age-related infertility. WHAT IS KNOWN ALREADY: A diagnosis of unexplained infertility is drawn when the diagnostic work-up fails to identify any patent cause. Although typically managed uniformly, unexplained infertility is likely to comprise a wide range of conditions, including age-related infertility (at least in older women). Unfortunately, no validated tests for the identification of age-related infertility exist and these women are typically treated as unexplained cases. However, homologous ART may be less effective for these women because these techniques may be unable to treat the detrimental effects of ageing on oocyte competence. STUDY DESIGN, SIZE, DURATION: Women aged 18-42 years who underwent IVF procedures between January 2014 and December 2021 were selected retrospectively. In the first part of the study, we aimed to assess whether the proportion of women with unexplained infertility (i.e. without patent causes of infertility) increased with age. In the second part of the study, women with unexplained infertility were matched 1:1 by age, study period, and duration of infertility, to those with a patent cause of infertility. If our hypothesis is valid, the first part of the study should highlight an increase in the proportion of unexplained infertility with age. Moreover, in the second part of the study, one should observe a sharper decrease in the rate of IVF success of the procedure with age in women with an unremarkable work-up compared to those with a definite cause of infertility. PARTICIPANTS/MATERIALS, SETTING, METHODS: Women were included if: they had been trying to conceive for more than 2 years, they had retrieved more than three oocytes, and had not undergone previous IVF attempts. We exclude couples with severe male factor (criptozoospermia), chronic anovulation, untreated hydrosalpinx, or intracavitary diseases. The first part of the study aimed at investigating the relative proportion of unexplained infertility with age. The outcome of the second part was the distribution of the live births between unexplained versus explained infertility, in women younger or older than 35 years. Only the results of the first IVF cycle were considered (including both fresh and frozen cycles). The live birth rate corresponded to the cumulative chance of a live birth per oocyte retrieval. MAIN RESULTS AND THE ROLE OF CHANCE: One thousand five hundred and thirty-five women were selected for the first part of the study; 742 of them had unexplained infertility (48%). The frequency of this diagnosis was lower among women aged <35 years (40%) compared to those ≥35 years (52%) (P < 0.001). A clear gradient emerged when considering smaller intervals of age (P < 0.001). A total of 1134 women (567 unexplained cases and 567 explained cases) were selected for the second part of the study. Baseline variables were comparable between women with unexplained and explained infertility. Among women younger than 35 years (n = 229 unexplained cases and 229 explained cases), 108 live births were observed in women with unexplained infertility (47%) and 88 in those with explained infertility (38%). In comparison, among women older than 35 years, the live births occurred in 90 (27%) and 114 (34%) couples, respectively (P = 0.03). The adjusted odds ratio (OR) for a live birth in older women with unexplained infertility was 0.63 (95% CI: 0.43-0.94). In other words, the effectiveness of IVF in older women with unexplained infertility is reduced by an additional 37% when compared to women of similar age with a patent cause of infertility. Moreover, when considering smaller intervals of age, a gradient of the adverse effect of age on the distribution of live births between unexplained and explained infertility emerged (P = 0.003). Overall, these results support the hypothesis that IVF may be of modest benefit in women with age-related infertility. The decline in IVF success is sharper in women with unexplained infertility compared to those with explained infertility, indirectly suggesting that IVF cannot effectively treat age-related infertility. LIMITATIONS, REASONS FOR CAUTION: We postulated that the greater decline in IVF success with age in the unexplained group could be related to the concomitant increase in the proportion of women with age-related infertility. However, even if this is theoretically logical, the unavailability of validated tools to diagnose age-related infertility makes our inference speculative. We cannot exclude that the prevalence of other unknown causes of infertility that cannot also be effectively overcome with IVF could increase with age. WIDER IMPLICATIONS OF THE FINDINGS: Our findings suggest that IVF may be of modest utility for treating age-related infertility. Offering this procedure to older women with an unremarkable infertility work-up may be questioned. However, the diagnosis of age-related infertility remains challenging and identifying a biomarker that could reliably diagnose age-related infertility is a priority. STUDY FUNDING/COMPETING INTEREST(S): The study was partially funded by the Italian Ministry of Health-current research IRCCS and by a specific grant supported by Ferring. ES declares receiving honoraria for lectures at meetings from IBSA and Gedeon-Richter and he also handles private grants of research from Ferring, IBSA, Theramex, and Gedeon-Richter. All the other authors do not have any conflict of interest to declare. TRIAL REGISTRATION NUMBER: N/A.

The impact of a second embryo biopsy for preimplantation genetic testing for monogenic diseases (PGT-M) with inconclusive results on pregnancy potential: results from a matched case-control study.

PURPOSE: To evaluate whether a second biopsy, following a first diagnostic failure on blastocysts tested for preimplantation genetic testing for monogenic diseases (PGT-M), allows to obtain genetic diagnosis and to what extent this procedure can influence clinical pregnancy and live birth rates compared to the PGT-M process with a successful genetic diagnosis from the first biopsy. METHODS: Embryos from women who underwent PGT-M in an infertility centre and who had been transferred after two biopsies for genetic analysis (n = 27) were matched in a 1:1 ratio accordingly to women's age (± 1 year) and fertility status (fertile vs infertile), as well as with the study period, with embryos who were transferred after receiving a conclusive PGT result straight after the first biopsy (n = 27). The main evaluated outcome was clinical pregnancy rate following embryo transfers in which healthy embryos were transferred after only one biopsy and those in which an embryo was transferred after being re-biopsied. Live birth rate was the secondary outcome. RESULTS: Clinical pregnancy rate was 52% (95% CI: 34-69) following the transfer of a single-biopsy blastocyst and 30% (95% CI: 16-48) following the transfer of a re-biopsied blastocyst. The likelihood to have a healthy baby was 33% (95% CI: 19-52) following the transfer of a blastocyst biopsied once and 22% (95% CI: 11-41) following the transfer of a re-biopsied blastocyst. CONCLUSIONS: The re-biopsy intervention seems to considerably reduce the pregnancy potential of a blastocyst. However, a greater sample size is necessary to clarify this issue definitively.

Return rate following a live birth obtained with ART: frequency and determinants.

PURPOSE: To understand how often couples return to ART centres for a second child. METHODS: Retrospective monocentric cohort study including women who had a first live birth with IVF. The primary objective was to assess the rate of those returning for a second child within five years of the previous pregnancy. The secondary aim was to disentangle the determinants of this rate. RESULTS: A total of 374 patients were included, of whom 188 returned (50%, 95% CI 45-55%). Among those who did not return (n = 186), four (2%) referred to another ART Center and 24 were unreachable. Of the 158 contacted subjects that did not refer for ART, 53 (34%, 95% CI 27-41%) conceived naturally, 57 (36%, 95% CI 29-44%) abandoned their intent of parenthood, and 48 (30%, 95% CI 24-38%) unsuccessfully attempted natural conception. These 48 women (13%) who expressed interest in a second child but did not undergo ART were compared to those seeking a second pregnancy through ART. Baseline characteristics were similar except for an older age (Median 36, IQR: 34-38 vs 34, IQR: 32-36, p = 0.001). Additionally, in terms of IVF cycle characteristics, women who did not return were more likely to achieve their first pregnancy with a fresh transfer rather than a frozen transfer (75% vs 59%, p = 0.05). They also had a higher number of retrieved oocytes (Median 10, IQR: 7-13 vs 9, IQR: 5-12) and less frequently cryopreserved embryos (27% vs 52%, p = 0.003). CONCLUSION: The proportion of couples who have conceived with ART and who are interested in having a second child is high. Our results underline the importance of paying more attention to the number of intended children, as this information could influence clinical management.

The effect of laser-assisted hatching on vitrified/warmed blastocysts: the ALADDIN randomized controlled trial.

OBJECTIVE: To evaluate whether laser-mediated assisted hatching (AH) performed on vitrified/warmed blastocysts before embryo transfer can improve live birth rate. DESIGN: The "pArtiaL zonA pelluciDa removal by assisteD hatchINg of blastocysts (ALADDIN)" is a 2-center comparative study with a parallel randomized controlled design. SETTING: University hospital. PATIENTS: Participants were recruited between September 2018 and November 2021. They were aged 18-39 years, underwent nondonor in vitro fertilization cycles, and were scheduled for elective single embryo transfer with vitrified/warmed blastocysts. Those with uterine abnormalities, body mass index of >35 kg/m2, severe male factor infertility, or performing preimplantation genetic testing were excluded. INTERVENTION: Assisted hatching was performed using a 1,480 nm diode laser, removing approximately one-third of the zona pellucida with continuous 0.2 ms pulses applied from the 1-5 o'clock positions. MAIN OUTCOME MEASURES: The primary outcome was the live birth rate. Secondary end points included clinical pregnancy, miscarriage, multiple pregnancies, preterm births, obstetric and neonatal complications, and congenital anomalies. RESULTS: Overall, 698 participants met the inclusion criteria and were randomized: 352 patients were assigned to the AH arm and 346 to the control arm. Of the participants, 105 (29.8%) and 101 (29.2%), respectively, achieved a live birth after treatment. The relative risk of live birth in patients with vitrified/warmed blastocysts treated with AH was 1.02 (95% confidence interval, 0.86-1.19). Exploratory subgroup analyses for women's age, recruiting centers, indications for in vitro fertilization, method of insemination, blastocyst quality, and days of blastocyst development failed to highlight any clinical situation that could benefit from AH in thawed blastocysts. CONCLUSION: In patients undergoing frozen embryo transfer with vitrified/warmed blastocysts, laser AH does not improve the live birth rate. Further studies are required to rule out milder but potentially interesting benefits in specific subgroups of patients. TRIAL REGISTRATION: ClinicalTrials.gov: NCT03623659.

Conventional in vitro fertilisation rather than intracytoplasmic sperm injection when only one oocyte is retrieved: Time to overcome irrational fears.

BACKGROUND: The use of intracytoplasmic sperm injection (ICSI) currently extends beyond male factor infertility, notably replacing conventional in vitro fertilisation (IVF) in scenarios like limited oocyte availability, where it is used as a precaution against complete fertilisation failure. While existing studies on the use of conventional IVF in such situations provide some reassurance, the available evidence is somewhat insufficient and ICSI is commonly used. AIMS: To evaluate whether conventional IVF can be a feasible option when only one oocyte is retrieved. MATERIALS AND METHODS: A retrospective study was performed to evaluate the fertilisation rate with conventional IVF in women retrieving only one oocyte and whose partner had normal semen. The study aimed at evaluating whether the fertilisation rate was aligned with the threshold indicated by recognized IVF laboratory performance indicators (Vienna Consensus). Clinical pregnancy and live birth rates were secondary outcomes. RESULTS: Out of 304 cycles with a single oocyte inseminated with conventional IVF, 209 achieved normal fertilisation and 82 did not. Thirteen had no mature oocytes. The fertilisation rate was 69% (95% CI: 63-74%) and increased to 72% (95% CI: 66-77%) when immature oocytes were excluded. The fertilisation rate surpassed the minimum competency threshold of the Vienna Consensus (60%), even if below the benchmark value (75%). Clinical pregnancy and live birth rates per oocyte retrieval were 10% and 8%, respectively. Univariate and multivariate analyses failed to identify any predictive factor of fertilisation. CONCLUSION: Conventional IVF with one oocyte met Vienna Consensus standards even if it fell short of higher benchmarks.

Correction: Peripheral mitochondrial DNA, telomere length and DNA methylation as predictors of live birth in in vitro fertilization cycles.

[This corrects the article DOI: 10.1371/journal.pone.0261591.].

The relationship between CYP19A1 gene expression in luteinized granulosa cells and follicular estradiol output in women with endometriosis.

Endometriosis was claimed to negatively affect the intrafollicular environment, hindering oocyte competence. Previous studies evaluated expression levels of cytochrome P450 aromatase (CYP19A) in granulosa and cumulus oophorus cells collected from endometriosis women, but results are controversial. To further investigate the intrafollicular environment whose alteration may potentially disturb ovarian steroidogenesis in endometriosis, gene expression of CYP19A and of its upstream enzymes, StAR and 3ßHSD was assessed in luteinized granulosa cells isolated from follicular fluids (FF) collected during Assisted Reproduction Technology (ART) procedures in women with stage III-IV disease and from subjects without the condition. In a subgroup of patients, cumulus oophorus cells (COCs) were also assessed for CYP19A, StAR and 3ßHSD gene expression. No difference in mRNA expression of CYP19A1, StAR and 3ßHSD in both granulosa cells and COCs was observed between the two groups of patients. No significant difference was also found between estradiol FF levels detected in endometriosis patients (median=873, IQR=522-1221 ng/ml)) and control patients (median=878, IQR=609-1137 ng/ml). To gain more insight into the intrafollicular regulation of CYP19A in patients with endometriosis, associations between expression of the analyzed genes, systemic and follicular 17ß-estradiol levels and ART outcomes were assessed. While in the control group, levels of CYP19A1, StAR and 3ßHSD transcripts significantly correlated with follicular estradiol levels (adjusted R² of 0.60), no significant association was detected in affected women (adjusted R² of 0.23). After stratification of the populations based on the presence of the disease, CYP19A1 expression was shown to correlate with the number of oocytes retrieved [ß:- 1.214;95%CI: - 2.085 - (-0.343); p = 0.007] in the control group while this association was not present in patients with endometriosis [ß:- 0.003; 95%CI:- 0.468-0.461; p = 0.988)]. These results do not support data from the literature indicating a reduced aromatase expression in granulosa cells of affected women, but they highlight a potential subtle mechanism affecting the ovulation process in these women.

The impact of difficult embryo transfer on the success of IVF: a systematic review and meta-analysis.

The procedure of embryo transfer (ET) must be as gentle as possible since any traumatism may cause uterine contractility that interferes with the implantation. However, this ideal conduct is not always possible, and additional measures may be necessary (difficult ET). Different studies have evaluated the impact of difficult ET on the clinical pregnancy rate (CPR), but results were not univocal. The present systematic review and meta-analysis was aimed to provide a precise estimate of the possible detrimental effects of difficult ET on CPR. The study protocol was registered online (PROSPERO number: CRD42023387197). An electronic database search was performed to identify articles published until September 2022. The primary outcome was CPR. Fifteen studies fulfilled the inclusion criteria. Difficult ET significantly reduced the CPR (OR 0.70; 95%CI: 0.64-0.76; p < 0.0001. All pre-planned subgroup analyses according to study design (retrospective vs prospective studies), historical period (studies published before and after 2010), type of catheter, frequency of difficult cases (> or < 19%) and pregnancy rate (> or < 38%) confirmed the significant association. Difficult ET is associated with a significant reduction of CPR. Further studies are warranted to understand how to prevent or manage this common clinical situation.

Impact of Endometrial Preparation on the Maternal and Fetal Cardiovascular Variables of the First Trimester Combined Screening Test.

The modality of endometrial preparation for the transfer of frozen-thawed embryos may influence maternal and fetal adaptation to pregnancy and could thus impact the results of the first trimester combined screening test. We conducted a retrospective cross-sectional study on singleton pregnancies achieved by embryo transfer of a single frozen-thawed blastocyst, comparing two different endometrial preparation protocols: natural cycle (n = 174) and hormone replacement therapy (HRT) (n = 122). The primary outcome was the risk of preeclampsia at the first trimester combined screening test. Secondary endpoints included variable reflecting fetal cardiac function (nuchal translucency and fetal heart rate), maternal adaptation (median arterial blood pressure-MAP and uterine arteries pulsatility index-UtA-PI), and placentation (pregnancy associated plasma protein A and placental growth factor). The risk of early preeclampsia was comparable in the two groups (38% vs. a 28%, p = 0.12). However, women in the natural cycle group showed lower fetal heart rate (159 [155-164] vs. 164 [158-168], p = 0.002) and higher UtA-PI (0.96 [0.74-1.18] vs. 0.72 [0.58-0.90], p < 0.001). The frequency of a screening test at high risk for aneuploidies was similar. The modality of transfer of frozen-thawed embryos is associated with changes in the variables reflecting maternal and fetal cardiovascular function.

Is endometrial receptivity affected in women with endometriosis? Results from a matched pair case-control study of assisted reproductive technology treatments.

RESEARCH QUESTION: Is endometriosis detrimental to embryo implantation? DESIGN: A retrospective matched case-control study of women with a surgical or ultrasound diagnosis of endometriosis at Fondazione IRCCS Ca'Granda Ospedale Maggiore Policlinico di Milano between 2015 and 2021. Women with endometriosis who underwent a 'freeze-all' cycle during an IVF treatment were eligible to be included. They were matched to patients without the disease, who also underwent cryopreserved blastocyst transfer cycles, in a 1:1 ratio by age (±1 year), and number (=) and quality (±1 top versus low) of cryopreserved blastocysts. All women underwent single frozen embryo transfer, and assisted reproductive technology outcomes suggested by the Core Outcome Measure for Infertility Trials initiative were evaluated. The main outcome was the cumulative live birth rate per cycle. RESULTS: One hundred and one women with endometriosis and 101 matched unaffected women were included. Cumulative live birth rate per cycle did not vary between women with and without endometriosis (50% versus 58%, respectively; P = 0.32). On the basis of the Kaplan-Meier analysis, the predicted success rates over four embryos transferred were also similar (74% versus 82%, respectively; P = 0.67). CONCLUSION: In women with moderate or severe endometriosis, these retrospective results seem to indicate no or a limited effect of the disease on endometrial receptivity.

Prevalence and clinical effect of caesarean scar defects in women undergoing IVF.

RESEARCH QUESTION: How common are caesarean scar defects (isthmocele) among patients who have had previous caesarean delivery undergoing IVF for secondary infertility? Does the presence of isthmocele affect the chances of success of IVF? DESIGN: In this cohort study, women referred to an Italian public assisted reproduction centre between January 2016 and April 2021 were retrospectively reviewed. Women with a history of caesarean delivery and an indication for IVF were selected. On the basis of the local policy, all patients with a history of caesarean section underwent saline contrast sonography (SCS). Sonographic evaluation was standardized. RESULTS: One hundred and forty-four women were eligible, of whom 22 declined SCS and eight decided to delay pregnancy seeking. Overall, 114 women were available for data analysis. Seventy-six women were diagnosed with caesarean scar defects, corresponding to a prevalence of 67% (95% CI 58 to 75%). Baseline characteristics of women with and without isthmocele were similar. Conversely, the clinical pregnancy rate (adjusted OR 0.31, 95% CI 0.13 to 0.72) and live birth rate (adjusted OR 038, 95% CI 0.17 to 0.86) were significantly lower among affected women. No associations between specific sonographic defect characteristics and IVF outcome could be identified. CONCLUSIONS: Caesarean scar defects are common among women with a history of caesarean section requiring IVF. The presence of these lesions may reduce the chance of success of the procedure.

Follicular steroidogenesis in random start protocols for oocyte cryopreservation.

PURPOSE: Random start protocols are commonly used for oocyte cryopreservation in women with cancer. However, albeit generally reassuring, available evidence is still insufficient to rule out a sub-optimal cycle outcome. This study aimed to compare follicular steroidogenesis between women initiating the random start protocol in the luteal phase and those initiating in the follicular phase. METHODS: Consecutive women with cancer scheduled for oocyte cryostorage were prospectively recruited. We excluded those requiring a concomitant letrozole assumption. All women received a standardized protocol with recombinant FSH and GnRH antagonists. At the time of oocyte retrieval, follicular fluids were pooled, and a sample was collected and frozen at -80 °C. All samples were assayed concomitantly after thawing by liquid chromatography-tandem mass spectrometry. The concentration of 15 different steroid hormones was determined. RESULTS: Seventy-one women were recruited. Thirty-three initiated the ovarian stimulation in the luteal phase, while the remaining 38 initiated in the follicular phase. Baseline characteristics were generally similar. Cycle outcome did also not differ; the median (interquartile range) number of frozen mature oocytes was 9 (5-14) and 10 (5-21), respectively (p = 0.42). None of the 15 tested steroid hormones differed. CONCLUSIONS: The endocrine microenvironment surrounding oocytes is not markedly influenced by the phase of the menstrual cycle at the initiation of ovarian stimulation. This result further supports the validity of random start protocols.

Low ovarian reserve and risk of miscarriage in pregnancies derived from assisted reproductive technology.

STUDY QUESTION: Do low levels of anti-Müllerian hormone (AMH) or antral follicle count (AFC) properly predict miscarriage in young women conceiving with ART? SUMMARY ANSWER: Low ovarian reserve, as indicated by AMH or AFC, is not associated with miscarriage in young women conceiving with ART. WHAT IS KNOWN ALREADY: Presently, the impact of low ovarian reserve on the risk of miscarriage remains controversial. Some studies have reported an association between serum AMH levels and AFC and miscarriage, but others have failed to confirm these findings. The main limitation that undermines the reliability and consistency of the results is the confounding effect of female age. Indeed, after 35 years of age, on the one hand, the risk of miscarriage starts increasing because of impaired oocyte quality while, on the other, the physiological decline in AMH and AFC levels continues, thus hampering the possibility to properly explore the real effects of reduced ovarian reserve. Indeed, the two processes, i.e. the gradual loss of resting primordial follicles and the loss of oocyte quality, progress in parallel. In other words, the older the woman becomes, the higher is the risk of miscarriage, but one cannot distinguish between the effects of biological aging on oocyte quality and those mediated by a lower ovarian reserve. STUDY DESIGN SIZE DURATION: The present retrospective monocentric cohort study was carried out at Fondazione IRCSS Ca Granda Ospedale Maggiore Policlinico, Milan. All women referred to the ART Unit between 2014 and 2021 and who underwent either conventional IVF (c-IVF), ICSI, or IUI were reviewed. Only women younger than 35 were eligible because, up to this age, the risk of miscarriage is steady and not strictly related to age. PARTICIPANTS/MATERIALS SETTING METHODS: Women younger than 35 who achieved a singleton clinical pregnancy with c-IVF, ICSI, or IUI were selected. Women with patent causes of recurrent miscarriage were excluded, as well as those undergoing pregnancy termination for fetal or medical causes. Women who did and did not have a pregnancy loss before 20 weeks' gestation were compared. Detailed information was obtained from charts of the consulting patients. ART procedures were performed according to the standardized policy of our Unit. All women underwent serum AMH measurement and a transvaginal assessment of AFC prior to initiation of treatment. AMH levels were measured by a commercially available ELISA assay. To assess AFC, all identifiable antral follicles 2-10 mm in diameter at ultrasound were recorded. The primary outcome was the risk of miscarriage for women with serum AMH levels below 5 pmol/l. MAIN RESULTS AND THE ROLE OF CHANCE: There were 538 women were included, of whom 92 (17%) had a miscarriage. The areas under the ROC curves for prediction of miscarriage based on AMH levels and AFC were 0.51 (95% CI: 0.45-0.58) and 0.52 (95% CI: 0.45-0.59), respectively. The odds ratio (OR) of miscarriage for women with serum AMH levels below 5.0 pmol/l was 1.10 (95% CI: 0.51-2.36); the adjusted OR was 1.12 (95% CI: 0.51-2.45). Analyses were repeated considering other thresholds for AMH (2.9, 3.6 and 7.9 pmol/l) and for AFC (thresholds of 7 and 10). No associations emerged. LIMITATIONS REASONS FOR CAUTION: The retrospective design of the study hampered the collection of more precise but potentially relevant clinical information of the couples. We did not exclude women suffering from PCOS, a condition possibly associated with miscarriage. Moreover, the baseline characteristics of women who did and did not have a miscarriage differed in some characteristics. Thus, we adjusted the OR using a multivariate analysis, but we cannot fully exclude residual confounding effects. Finally, our results cannot be inferred to women older than 35. The mechanisms causing premature exhaustion of ovarian reserve may be different in younger and older women and this may lead to a different impact on the risk of miscarriage. WIDER IMPLICATIONS OF THE FINDINGS: Women embarking on ART with low ovarian reserve should be informed of their likely poor response to ovarian stimulation but can be reassured that, if conception occurs, their risk of miscarriage is not increased. STUDY FUNDING/COMPETING INTERESTS: This study was partially funded by Italian Ministry of Health-Current research IRCCS. E.S. reports grants from Ferring and honoraria for lectures from Merck-Serono and Gedeon-Richter. All the other authors do not have any competing interest to declare. TRIAL REGISTRATION NUMBER: N/A.

Adherence to the Mediterranean diet and the risk of unexpected poor response to ovarian stimulation in IVF cycles.

RESEARCH QUESTION: Can preconception adherence to a Mediterranean diet influence the rate of poor response to ovarian stimulation in IVF cycles? DESIGN: The impact of dietary habits on the success of IVF is controversial. Inconsistencies may be explained by confounders associated with the use of pregnancy as an outcome as well as by a reductionist view of diet that focuses on single components rather than on food patterns. This cross-sectional study analysed adherence to a Mediterranean diet in women with unexpected poor response to ovarian stimulation. Main inclusion criteria were: age 18-39 years, normal weight, preserved ovarian reserve and starting dose of gonadotrophins of 150-225 IU/day. Adherence to the Mediterranean diet was assessed through a Mediterranean diet score (MDS). Unexpected poor ovarian response was defined as the retrieval of ≤3 suitable oocytes. RESULTS: A total of 296 women were included, of whom 47 (15.9%) showed an unexpected poor response. A clear dose-related association with tertiles of MDS was not observed in the univariate analysis. However, in the multivariate analysis, the risk of unexpected poor response was significantly lower for women in the second tertile of MDS compared with the first tertile (adjusted odds ratio [OR] 0.29, 95% confidence interval [CI] 0.11-0.76) and for women in the second and third tertiles, grouped together, compared with the first tertile (adjusted OR 0.34, 95% CI 0.14-0.82). CONCLUSIONS: Low adherence to a Mediterranean diet could be a risk factor for unexpected poor ovarian response.

Progestin-primed ovarian stimulation for fertility preservation in women with cancer: A comparative study.

BACKGROUND: In women scheduled for cancer treatment, oocytes cryopreservation is a well-established procedure. Random start protocols have been a substantial improvement in this setting, allowing to prevent delay in the initiation of cancer treatments. However, there is still the need to optimize the regimen of ovarian stimulation, to make treatments more patient-friendly and to reduce costs. METHODS: This retrospective study compares two periods (2019 and 2020), corresponding to two different ovarian stimulation regimens. In 2019, women were treated with corifollitropin, recombinant FSH and GnRH antagonists. Ovulation was triggered with GnRH agonists. In 2020, the policy changed, and women were treated with a progestin-primed ovarian stimulation (PPOS) protocol with human menopausal gonadotropin (hMG) and dual trigger (GnRH agonist and low dose hCG) Continuous data are reported as median [Interquartile Range]. To overcome expected changes in baseline characteristics of the women, the primary outcome was the ratio between the number of mature oocytes retrieved and serum anti-mullerian hormone (AMH) in ng/ml. RESULTS: Overall, 124 women were selected, 46 in 2019 and 78 in 2020. The ratio between the number of mature oocytes retrieved and serum AMH in the first and second period was 4.0 [2.3-7.1] and 4.0 [2.7-6.8], respectively (p = 0.80). The number of scans was 3 [3-4] and 3 [2-3], respectively (p<0.001). The total costs of the drugs used for ovarian stimulation were 940 € [774-1,096 €] and 520 € [434-564 €], respectively (p<0.001). CONCLUSIONS: Random start PPOS with hMG and dual trigger represents an easy and affordable ovarian stimulation protocol for fertility preservation in women with cancer, showing similar efficacy and being more friendly and economical.

Is There a Correlation between the Second-to-Four Digit Ratio (2D:4D) and Endometriosis? Results of a Case-Control Study.

The second-to-four digit ratio (2D:4D) has been proposed as a marker of prenatal hormonal exposure. It is suggested that prenatal exposure to androgens results in a shorter 2D:4D ratio, whereas a prenatal oestrogenic environment results in a longer one. In addition, previous research has shown an association between exposure to endocrine-disrupting chemicals and 2D:4D in animals and humans. On the endometriosis side, hypothetically, a longer 2D:4D ratio, reflecting a lower androgenic intrauterine milieu, could represent an indicator of the presence of the disease. In this light, we have designed a case-control study to compare 2D:4D measurements between women with and without endometriosis. Exclusion criteria included the presence of PCOS and previous trauma on the hand that could impact the measurement of the digit ratio. The 2D:4D ratio of the right hand was measured using a digital calliper. A total of 424 participants (endometriosis n = 212; controls n = 212) were recruited. The group of cases included 114 women with endometriomas and 98 patients with deep infiltrating endometriosis. The 2D:4D ratio was significantly higher in women with endometriosis compared to controls (p = 0.002). There is an association between a higher 2D:4D ratio and the presence of endometriosis. Our results support the hypothesis claiming potential influences of intrauterine hormonal and endocrine disruptors exposure on the onset of the disease.

Conventional IVF performs similarly in women with and without endometriosis.

PURPOSE: A reduced oocyte competence has been claimed as one of the factors underlying infertility in women with endometriosis. This idea has justified the hypothesis that intracytoplasmic sperm injection (ICSI), rather than conventional IVF (c-IVF), may overcome oocyte impairment and ensure better assisted reproduction technology (ART) outcomes; however, data from the literature are controversial. Thus, the aim of this study was to compare ART success rates following (c-IVF) between women with and without endometriosis in the presence of normozoospermic partners. METHODS: This is a retrospective, matched case-control study of 314 patients who underwent c-IVF cycles between January 2014 and December 2020. Women with endometriosis were matched in a 1:1 ratio with patients undergoing ART for other indications, considering age (± 6 months), number of oocytes retrieved (± 1), and study period. The main outcome measures included total fertilization failure, fertilization rate, embryo quality, cumulative clinical pregnancy, and live birth rates. RESULTS: The fertilization rate and the proportion of women with total fertilization failure did not differ between women with and without endometriosis. Similarly, all other embryological variables did not also differ, except for the number of top-quality cleavage stage embryos which was higher in the endometriosis group. Cumulative clinical pregnancy and live birth rates were similar between women with and without endometriosis. CONCLUSION: A diagnosis of endometriosis does not negatively affect the performance of c-IVF; thus, c-IVF can be efficiently used in women affected, unless a male factor is also involved. This issue holds clinical relevance to help operators on their insemination technique decision-making.

The impact of small and asymptomatic intramural and subserosal fibroids on female fertility: a case-control study.

STUDY QUESTION: Do small and asymptomatic intramural and subserosal uterine fibroids affect female fertility? SUMMARY ANSWER: Small and asymptomatic fibroids that do not encroach the endometrial cavity appear to not markedly affect female fertility. WHAT IS KNOWN ALREADY: The available evidence on uterine fibroids and fertility is limited. Most information has been obtained in IVF settings by comparing the success in women affected and not affected by fibroids. These studies have shown a detrimental effect of submucosal and possibly intramural fibroids. However, this study design provides information only on embryo implantation, not on female fertility in general. STUDY DESIGN SIZE DURATION: A retrospective observational case-control study on 200 women whose partner was diagnosed with severe male infertility and 200 women with unexplained infertility was conducted. If the null hypothesis (that fibroids do not affect fertility) is valid, one would expect a similar prevalence of fibroids in the two study groups. Conversely, if fibroids do impact fertility, one would expect a higher prevalence among women with unexplained infertility. The study was carried out at the Infertility Unit of the Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico covering a 5-year period between January 2014 and June 2020. PARTICIPANTS/MATERIALS SETTING METHODS: We retrospectively recruited women seeking pregnancy whose partner was repeatedly documented to have a sperm concentration below 1 million/ml and matched them by age and study period to a group of women with unexplained infertility. The latter group of women was considered as a case group (infertile subjects), while the former group of women was considered as a control group (reflecting the general female population). Women with fibroids could be included in both study groups; only those with submucosal lesions were excluded. MAIN RESULTS AND THE ROLE OF CHANCE: Fibroids were diagnosed in 31 women (16%) with unexplained infertility and in 32 women (16%) with severe male factor infertility. The adjusted odds ratio of carrying fibroids in women with unexplained infertility was 0.91 (95% CI: 0.52-1.58). Subgroup analyses according to number, dimension and location of fibroids failed to highlight an increased risk of infertility in any group. LIMITATIONS REASONS FOR CAUTION: This is a retrospective study and some inaccuracies in fibroids detection cannot be ruled out. Moreover, the relatively small sample size hampers robust subgroup analyses. Even though we excluded women with patent causes of infertility, some women with specific causes of infertility could have been included among controls (yet are expected to account for <10% of the group). WIDER IMPLICATIONS OF THE FINDINGS: This study suggests that small fibroids that do not encroach the endometrial cavity do not markedly affect female fertility. This information is clinically relevant when counseling infertile women with small fibroids and an otherwise unremarkable diagnostic work-up. Surgery may still be considered but only in selected cases. STUDY FUNDING/COMPETING INTERESTS: This study was partially funded by Italian Ministry of Health: current research IRCCS. E.S. reports grants from Ferring, grants and personal fees from Merck, and grants and personal fees from Theramex outside the submitted work. All the other authors do not have any competing interest to declare. TRIAL REGISTRATION NUMBER: N/A.