Cumulative live birth and surplus embryo incidence after frozen-thaw cycles in PCOS: how many oocytes do we need?

The Efficacy of Letrozole Co-Treatment in an Antagonist Protocol for Women with Polycystic Ovary Syndrome Undergoing IVF: A Retrospective Study

Objective

Our objective was to investigate the efficacy of letrozole co-treatment in an antagonist protocol for infertile women with polycystic ovary syndrome (PCOS).

Patients and Methods

This retrospective cohort study included infertile women with PCOS undergoing IVF/ICSI with and without letrozole co-treatment in an antagonist protocol from 2007-2021 at Shanghai Ninth People's Hospital (Shanghai, China). A total of 1559 participants were enrolled, with 1227 women in the antagonist group and 332 women in the letrozole co-treatment group. Propensity score-based patient-matching model was conducted to balance covariates between the groups. The primary outcome was the number of retrieved oocytes, with secondary outcomes including endocrine parameters, ovarian stimulation outcomes, pregnancy outcomes, and obstetrical and neonatal complications.

Results

Letrozole co-treatment induced significant changes in hormonal regulation, increased the percentage of large follicles, and resulted in fewer retrieved oocytes (P < 0.05). However, there was no negative impact on the number of usable embryos or good-quality embryos (P > 0.05). The live birth rates following fresh embryo transfer were comparable between the letrozole and control groups (single embryo transfer: 28.9% vs 29.7%, P > 0.05; double embryo transfer: 37.3% vs 45.6%, P > 0.05). Additionally, there were no significant differences between the two groups in the live birth rate per patient after frozen embryo transfer and the cumulative live birth rate (P > 0.05). No significant differences in obstetrical and neonatal complications were observed between the groups (P > 0.05).

Conclusion

The addition of letrozole to the antagonist protocol for women with PCOS undergoing IVF induces a higher percentage of large follicles during oocyte retrieval, while reducing the overall number of retrieved oocytes. Moreover, the use of letrozole demonstrates comparable clinical outcomes following embryo transfers. These findings highlight the potential application of letrozole in an antagonist protocol for women with PCOS.

Too many embryos: a critical perspective on a global challenge

Over the past decade, significant endeavors have been directed toward establishing an optimal oocyte number to maximize the chances for successful in vitro fertilization outcomes. The effectiveness of assisted reproductive technologies has greatly improved, and more good-quality embryos are being created in each cycle. However, many of these embryos remain unused. Notably, in Europe, approximately one-third of couples did not use their surplus cryopreserved embryos. Surplus embryos pose a challenge for patients and clinics. Embryo disposal practices are not the same all over the continent, with embryo donation and embryo discharge not allowed in several countries. In this scenario, limiting the number of surplus embryos by reducing the number of inseminated oocytes, according to couple clinical history, could be a strategy.

Cut-off point of mature oocyte for routine clinical application of rescue IVM: a retrospective cohort study

BACKGROUND

The rescue in vitro mature(Rescue IVM) technique allows the use of immature oocytes collected in conventional COH to obtain more mature oocytes for fertilization through in vitro maturation. Some studies have shown that Rescue IVM could improve clinical outcomes in patients undergoing IVF/ICSI, but the effectiveness and the indications for the clinical application of this technique remain controversial. It remains to be studied whether Rescue IVM should be universally applied in all conventional IVF/ICSI cycles.

METHOD

This is a large retrospective cohort study that included a total of 22,135 female patients undergoing their first IVF treatment cycles. The effect of the number of mature oocytes(metaphaseII[MII]) on the cumulative live birth rate was investigated in a population with routine IVF/ICSI first. The receiver operating characteristic curve(ROC) analysis was used to explore the cut-off point of the number of MII affecting CLBR. Secondly, Patients undergoing ICSI with Rescue IVM were included in the analysis with those who underwent ICSI only during the same period, grouped according to the MII cut-off values. Multi-factor binary logistic regression and inverse probability weighting (IPW) were used to investigate whether Rescue IVM influenced the final cumulative live birth rate(CLBR).

RESULTS

The CLBR increased with the number of MIIoocytes (P < 0.001). The ROC analysis showed the cut-off point for the number of MIIoocytes to have a significant effect on CLBR was 9 (sensitivity 0.715, specificity 0.656). Furthermore, 912 patients who underwent ICSI with Rescue IVM were included and compared to those who underwent ICSI only during the same period, and found Rescue IVM significantly increased the number of available MIIoocytes. For patients with MII numbers < 9, Rescue IVM significantly improves their clinical pregnancy rate(55.6% vs. 46.7%, P = 0.001) and CLBR(65.4% vs. 48.1%, P < 0.001), but not for those patients with MII numbers ≥ 9.

CONCLUSION

This study further clarifies the candidates for the application of Rescue IVM technique: patients with an MII oocytes < 9 in a conventional IVF/ICSI cycle. In contrast, it is not necessary for patients who already have sufficient mature oocytes(≥ 9), to avoid over-medication.

Factors affecting cumulative live birth rate after the 1st oocyte retrieved in polycystic ovary syndrome patients in women during IVF/ICSI-ET

BACKGROUND

The factors affecting the cumulative live birth rate (CLBR) of PCOS (Polycystic ovary syndrom) patients who received in vitro fertilization/intracytoplasmic sperm injection-embryo transfer (IVF/ICSI-ET) needs more research for a better outcome.

METHODS

Here we carried out a retrospective analysis of 1380 PCOS patients who received IVF/ICSI-ET for the first time from January 2014 to December 2016. We divided them into cumulative live birth group (group A) and non-cumulative live birth group (group B) according to whether there were live births.

RESULTS

The conservative cumulative live birth rate was 63.48%. There were 876 cumulative live births (group A) and 504 non-cumulative live births (group B) according to whether the patients had live births or not. Competition analysis showed that duration of infertility, primary/secondary type of infertility, stimulation protocols, starting dose of gonadotrophins and oocyte retrieved numbers were significantly correlated with CLBR. The Cox proportional risk regression model of PCOS patients showed that stimulation protocols had a significant impact on CLBR. Patients in the GnRH (Gonadotropin-releasing hormone)-antagonist protocol group and the mild stimulation protocol had lower CLBR than those in the prolonged GnRH-agonist protocol, which was statistically significant. PCOS patients with the starting dose of gonadotrophins greater than 112.5u had lower CLBR than those with less than 100u, which was statistically significant. Women with 11-15 oocytes and 16-20 oocytes had higher CLBR than women with 1-9 oocytes, which was statistically significant.

CONCLUSIONS

When we used Prolonged GnRH-agonist protocol, or the first starting dose of gonadotrophins was 100u-112.5u, or the number of oocytes obtained was 11-15 and 16-20, the CLBR of PCOS patients increased significantly after the 1st oocyte collection.

Association between the number of oocytes and cumulative live birth rate: A systematic review

The available literature is controversial regarding the association between the number of oocytes retrieved and the cumulative live birth rate (CLBR). Although some authors report a continuous increase in the CLBR with the number of oocytes retrieved, others have found a plateau. A systematic review was conducted, including all eligible studies published until June 2022, to determine the optimal number of oocytes retrieved to maximize the CLBR. We found a positive association between the number of oocytes and the CLBR. However, this association varies according to patients' age. While in patients younger than 35 years, little benefit is derived from increasing the number of oocytes above 25-30, in patients older than 35 years, the number of oocytes seems to improve the CLBR until the extreme of reproductive age is reached. In women aged 44 years or older, the CLBR will be consistently low, independent of the number of oocytes retrieved.

Female infertility in the era of obesity: The clash of two pandemics or inevitable consequence?

Obesity is an epidemic that has led to a rise in the incidence of many comorbidities: among others, reduced fertility is often under-evaluated in clinical practice. The mechanisms underlying the link between reduced fertility and obesity are numerous, with insulin resistance, hyperglycaemia and the frequent coexistence of polycystic ovary syndrome being the most acknowledged. However, several other factors concur, such as gut microbiome alterations, low-grade chronic inflammation and oxidative stress. Not only do women with obesity take longer to conceive, but in vitro fertilization (IVF) is also less likely to succeed. We herein provide an updated state-of-the-art regarding the molecular bases of what we could define as dysmetabolic infertility, focusing on the clinical aspects, as well as possible treatment.

In vitro maturation of human oocytes maintaining good development potential for rescue intracytoplasmic sperm injection with fresh sperm

BACKGROUND

The outcomes of the use of commercial in vitro maturation (IVM) medium to culture immature oocytes obtained from conventional ovulation induction, followed by rescue intracytoplasmic sperm injection (RICSI), are not ideal. It is thus difficult to widely adopt this approach in clinical practice. Therefore, it is necessary to explore methods for improving the clinical outcome of IVM.

AIM

To study the effect of sperm on the developmental potential of in vitro-matured oocytes in conventional culture.

METHODS

This was a retrospective study of patients whose immature oocytes were harvested from conventional oocyte stimulation cycles and underwent ICSI at our hospital between June 2018 and August 2020. RICSI was performed using sperm collected on the day of oocyte harvest (old) and sperm collected on the day of RICSI (fresh) and oocytes matured in vitro after 24 h of culture in conventional medium. The rates of in vitro oocyte maturation, normal fertilization, normal cleavage, day-3 top-quality embryos, and useful blastocyst formation were compared between the two groups.

RESULTS

In total, 102 germinal vesicle (GV)-stage immature oocytes were cultured in the old sperm group. In the fresh sperm group, 122 GV-stage immature oocytes were collected and cultured in vitro for 24 h. There were no significant differences in the general conditions of males and females between the two groups (P > 0.05). The oocyte maturation, normal fertilization, and normal cleavage rates of the old and fresh groups were 51.0% vs 55.7%, 61.5% vs 64.7%, and 93.8% vs 93.2%, respectively. None of the rates differed significantly (P > 0.05) between the two groups. However, the day-3 top-quality embryo and useful blastocyst rates of the old and fresh sperm groups were 16.6% vs 63.4%; 6.67% vs 34.6%, respectively. The day-3 top-quality embryos and useful blastocyst rates of the old sperm group were significantly lower than those of the fresh group (P < 0.05).

CONCLUSION

In vitro maturation with conventional culture medium combined with the use of fresh sperm collected on the day of RICSI is an easy-to-implement strategy for patients whose oocytes are completely or mostly immature.

The Optimal Number of Oocytes Retrieved From PCOS Patients Receiving IVF to Obtain Associated With Maximum Cumulative Live Birth Rate and Live Birth After Fresh Embryo Transfer

AIMS

This study aims to determine the optimal number of oocytes retrieved so that patients with polycystic ovary syndrome (PCOS) receiving in vitro fertilization (IVF) can obtain the best cumulative live birth rate (CLBR) and live birth after fresh embryo transfer.

METHODS

This is a retrospective study of 1,419 patients with PCOS who underwent their first IVF cycle at the Second Hospital of Hebei Medical University from January 2014 to December 2021. Multivariable regression analysis was performed to adjust for factors known to independently affect cumulative live birth aspiration. The number of oocytes retrieved to obtain the best cumulative live birth rate was explored through curve fitting and threshold effect analysis. The decision tree method was used to explore the best number of oocytes retrieved to achieve live birth in the shortest time.

RESULTS

(1) The number of oocytes retrieved was found to be an independent protective factor for the cumulative live birth rate (OR = 1.09 (95% CI: 1.06, 1.12)). When the number of oocytes retrieved was less than 15, CLBR increased by 16% with each increase in the number of oocytes retrieved (OR = 1.16 (95% CI: 1.11, 1.22)); and when more than 15, CLBR tended to be stable. (2) Live birth after the first fresh embryo transfer was analyzed through a classification decision tree. For patients younger than 35 years old, those with less than 6 oocytes and those with 7-16 oocytes had a similar proportion of live births with fresh embryo transfer but higher than 16 oocytes (53.7% vs. 53.8% vs. 18.4%). Patients older than 35 years old had a similar proportion of live births with fresh embryo transfer (35.7% vs. 39.0%) to those younger than 35 years old, but the proportion of no live births after using up all embryos was higher than those younger than 35 years old (39.3% vs. 19.2%).

CONCLUSIONS

In PCOS patients, high CLBR can be obtained when the number of oocytes retrieved was 15 or more. The number of oocytes retrieved from 7 to 16 could achieve more chance of live birth after fresh embryo transfer.

Cumulative live birth rate per oocyte aspiration in artificial reproduction technology: A retrospective observational study of the association between maternal age and the number of oocytes retrieved in an Indian population

Background:

The association between cumulative live birth rate (CLBR) and oocyte aspiration in the context of maternal age is not well understood in the Indian population.

Aims:

To find the relationship between CLBR and a single oocyte aspiration.

Settings and Design:

This is a retrospective study analysing the data of 1989 women who underwent in vitro fertilisation (IVF) between January 2015 and December 2019, at Gunasheela Surgical and Maternity Hospital, India.

Materials and Methods:

Participants were divided into two groups based on age: ≤35 (group I, n = 1665) and >35 (Group II, n = 324). CLBR per single oocyte aspiration in fresh and subsequent three frozen embryo transfer cycles was estimated.

Statistical Analysis Used:

Logistic regression analysis was used to show the likelihood of pregnancy rate, and CLBR per aspiration after treatment was represented as odd's ratios (OR) with 95% confidence intervals.

Results:

Maximal CLBR for Groups I and II was 81.25% with >25 oocytes and 75% with 16–20 oocytes, respectively. In the fresh ET cycle, maximal pregnancy and live birth rates were observed in 6–10 oocytes for Group I (54% and 41%) and in 16–20 oocytes for Group II (75% and 75%). The ORs for pregnancy rate (P = 0.01) and CLBR (P = 0.007) increased with an increase in the number of oocytes retrieved. The ORs for pregnancy rate and CLBR for Group II were 0.68 (P = 0.002) and 0.58 (P = 0.00002), respectively as compared to Group I. Optimal oocytes required to achieve positive IVF outcomes in fresh/frozen ET cycles were low in Group I (6–10 oocytes), but higher in Group II (16–20 oocytes).

Conclusion:

Robust positive relationship was observed between the number of oocytes retrieved and CLBR in women of both age groups.

Identification of small extracellular vesicle-linked miRNA specifically derived from intrafollicular cells in women with polycystic ovary syndrome

RESEARCH QUESTION

This study aimed to identify small extracellular vesicle (sEV)-linked microRNAs (miRNA) specifically derived from intrafollicular cells in women with polycystic ovary syndrome (PCOS) and to investigate their biological functions.

DESIGN

A total of 120 women were recruited from September 2017 to October 2018. To investigate miRNA profiles in sEV derived from follicular fluid and serum, 30 women with PCOS and 30 without PCOS were included for a miRNA microarray containing probes interrogating 2549 human miRNA. To study the expression levels of differentially expressed miRNA, sEV in follicular fluid obtained from another 30 PCOS and 30 non-PCOS patients were used for quantitative real-time polymerase chain reaction analysis.

RESULTS

A total of 281 sEV-linked miRNA specifically derived from intrafollicular cells were identified, 179 of which were expressed in both the PCOS and non-PCOS groups. Twenty-six of the 179 intrafollicle-specific sEV-linked miRNA were predicted to target 1537 genes. Functional analysis suggested that these genes were involved in pathways related to folliculogenesis, including the MAPK, and PI3K-Akt signalling pathways. Quantitative real-time polymerase chain reaction analysis showed that the expression of seven intrafollicle-specific sEV-linked miRNA was significantly higher in follicular fluid-derived sEV in women with PCOS than in women without it. These miRNA and their corresponding target genes were identified as being involved in the MAPK signalling pathway and oocyte meiosis.

CONCLUSIONS

The data suggest that the aberrantly expressed miRNA and their target genes might be associated with PCOS, providing novel insights into the molecular mechanisms underlying regulation of folliculogenesis and oocyte maturation in PCOS.

High Serum Anti-Müllerian Hormone Concentrations Are Associated With Poor Pregnancy Outcome in Fresh IVF/ICSI Cycle but Not Cumulative Live Birth Rate in PCOS Patients

OBJECTIVE

To investigate the association between baseline serum Anti-Müllerian hormone (AMH) levels and IVF/ICSI outcomes in women with polycystic ovary syndrome (PCOS).

DESIGN

Retrospective study.

SETTING

Reproductive medicine center in a hospital.

POPULATION

2436 PCOS patients (Rotterdam criteria) who underwent their first fresh IVF/ICSI cycles were divided into three groups on the basis of the <25th (Group 1, n=611), 25 to 75th (Group 2, n=1216), or >75th (Group 3, n=609) percentile of baseline serum AMH level.

INTERVENTIONS

Baseline serum AMH levels measured on the 2-3 days of spontaneous menstrual cycle before IVF/ICSI treatment.

MAIN OUTCOME MEASURES

Live birth rate (LBR), cumulative live birth rate (CLBR), clinical pregnancy rate (CPR), and normal fertilization rate (FR).

RESULTS

The LBR, CPR, and FR were significantly increased in Group 1 than Group 2 and Group 3, however, CLBR was similar between the three groups. The LBR were 46.6%, 40.5%, and 39.4% in Group 1, Group 2, and Group 3 respectively. The CPR were 53.0%, 47.0%, and 45.5%, respectively. The FR was highest in Group 1 (61.7%, P<0.05), but there was no uniform reverse trend with the AMH level. CLBR were 68.7%, 70.4%, and 71.3%, respectively. Although women in Group 1 were older (p < 0.05) and had higher body mass index (BMI) (p < 0.05), binomial logistic regression analysis used age, BMI, FSH, and AMH as independent variables indicated that only AMH was significantly associated with LBR and CPR. Nevertheless, binomial logistic regression analysis used age, BMI, FSH, AMH, and the number of retrieved oocytes as independent variables indicated that only the number of retrieved oocytes was significantly correlated with CLBR. After stratifying by age, the negative relationship between baseline AMH level and LBR and CPR remained only in the patients <30 years old.

CONCLUSIONS

Higher baseline AMH level in PCOS women resulted in lower LBR, CPR, and FR but did not influence CLBR.

Is there an optimal number of oocytes retrieved at which live birth rates or cumulative live birth rates per aspiration are maximized after ART? A systematic review

The association between the number of oocytes retrieved and fresh live birth rate (LBR) or cumulative LBR (CLBR), and whether an optimal number of oocytes are retrieved when LBR or CLBR are maximized, are highly relevant clinical questions; however published results are conflicting. A systematic review of all eligible studies (n = 16) published until January 2020 on MEDLINE, Embase, Scopus, CINAHL and Web of Science was conducted. Five studies evaluated only LBR from fresh cycles, five studies evaluated only CLBR from stimulated cycles and six evaluated both. A marked difference was observed between the oocyte yields at which LBR and CLBR were reportedly maximized in the individual studies. On the basis of nine studies, the optimal number of oocytes at which fresh LBR seems to be maximized is proposed to be between 12 and 18 oocytes (15 oocytes was the most common suggestion). On the other hand, CLBR continues to increase with the number of oocytes retrieved. This is the first systematic review on the topic, and it suggests that the retrieval of 12-18 oocytes is associated with maximal fresh LBR, whereas a continuing positive association is present between the number of oocytes retrieved and CLBR.

Pregnancy and perinatal outcomes in pregnancies resulting from time interval between a freeze-all cycle and a subsequent frozen-thawed single blastocyst transfer

Background

Adverse obstetric outcomes are correlated with altered circulating hormone levels at the time implantation by the trophectoderm. What’ more, embryo freezing process may also have adverse effect on perinatal outcomes. This study aims to evaluate whether increasing interval time between a freeze-all cycle and a subsequent frozen-thawed single blastocyst transfer could have any effect on pregnancy and perinatal outcomes.

Methods

This was a retrospective cohort study included the first single blastocyst transfer in artificially cycles of all patients who underwent a freeze-all cycle between January 1^st, 2016 and September 30^th, 2018. All patients were divided into two groups according to the time interval between oocyte retrieval and the day of first frozen-thawed embryo transferred (FET): Group 1 (immediate FET cycles) and Group 2 (delayed FET cycles).

Results

No significant differences were reported between the two groups regarding the rates of clinical pregnancy, live birth, biochemical pregnancy and pregnancy loss even after adjusting for measured confounding. When accounting for perinatal outcomes, gestational age, birth weight, delivery mode, fetus gender, preterm birth, gestational hypertension, GDM, placenta previa, fetal malformation and low birthweight also did not vary significantly between the two groups. Only the incidence of macrosomia was more frequently in the Group 2 compared with the Group 1 (AOR 3.886, 95%CI 1.153–13.103, P = 0.029) after adjusting with a multiple logistic regression model.

Conclusions

We found delayed FET cycles for blastocyst transfer following freeze-all cycles may not improve the pregnancy outcomes. On the contrary, postponement of FET cycles may increase the risk of macrosomia. Therefore, FET cycles for blastocyst transfer should be done immediately to avoid adverse effects of delayed time on perinatal outcomes.

Cumulative live birth rates according to the number of oocytes retrieved following the "freeze-all" strategy

BACKGROUND

In recent years, some studies have shown that there is a positive association between the number of oocytes retrieved and the cumulative live birth rate (CLBR) after fresh and frozen cycles of one oocyte retrieval. However, almost no studies have examined the association between the number of oocytes retrieved and the CLBR when using the "freeze-all" strategy. We performed this study to investigate the effects of an extreme oocyte yield during the first "freeze-all" cycle on the cumulative live birth rate among patients younger than 35 years old.

METHODS

This was a retrospective cohort study performed in a university-affiliated reproductive medicine centre. Data obtained from 3276 women aged younger than 35 years who underwent their first "freeze-all" cycle (IVF/ICSI) were collected between January 2009 and December 2016. In all, 5025 frozen cycles took place during the follow-up period from January 2009 to December 2018. Patients were divided into five groups according to oocytes retrieved (group 1: 4-10 oocytes; group 2: 11-20 oocytes; group 3: 21-30 oocytes; group 4: 31-40 oocytes; group 5: > 40 oocytes). The primary outcome was the cumulative live birth rate.

RESULTS

Unadjusted results showed that the cumulative live birth rate significantly increased as the number of oocytes retrieved increased and reached up to 93.82% in cases with yields of 21-30 oocytes (P < 0.05), after which it did not have a significant increase (P > 0.05). After adjusting for confounders, our results showed that the number of oocytes retrieved is an independent positive predictor of cumulative live birth rate when using a "freeze-all" strategy. (P < 0.001). In addition, the fertilization rate and the gonadotropin dose also influenced the cumulative live birth rate (P<0.05).

CONCLUSIONS

Among women younger than 35 years old who underwent the "freeze-all" strategy, the number of oocytes retrieved positively correlated with the cumulative live birth rate. Taking both efficacy and safety into account, ovarian stimulation should be rational, and the upper limit of the oocyte yield should be no more than 30.

[Polycystic ovary syndrome does not affect blastulation nor cumulative live birth rates]

OBJECTIVES

Polycystic ovarian syndrome (PCOS) brings complications in the management of the assisted reproductive technology (ART) because of an oocyte quality probably impaired due to modifications of intra- and extra-ovarian factors. Our study aimed to investigate the extended culture in PCOS patients and its influence on the cumulative live birth rates.

METHODS

Fifty-nine PCOS patients (as defined by the Rotterdam criteria) and 114 normo-ovulatory patients (i.e. with tubal, male or idiopathic infertility, regular cycles and AMH>2ng/mL) aged<37years old who underwent a 1st or 2nd ART attempt with extended culture to day 6 were included from October 2015 to December 2017. The blastulation and cumulative live birth rates were compared between the two groups.

RESULTS

The PCOS and control patients were 32.22 and 32.91years old respectively (P=0.05). The median number of oocytes retrieved was significantly higher in the PCOS group and the median oocyte maturity rate significantly lower compared with controls. The blastulation rates were similar between the PCOS and the control groups, respectively 57.8% vs. 58.6%, P=0.88. Because of the risks of hyperstimulation syndrome, a freeze all strategy was achieved for 38.9% of PCOS patients vs. 14.0% of the control patients (P<0.01). The cumulative live birth rates were not statistically different: 31.7% in the PCOS group vs. 37.2% in the control group, P=0.50.

CONCLUSIONS

PCOS was not observed to affect the extended culture nor the cumulative live birth rates in comparison to normo-ovulatory patients, supporting the blastocyst transfer strategy as a suitable option to PCOS patients.