In vitro maturation or in vitro fertilization for women with polycystic ovaries? A case–control study of 194 treatment cycles

The severity of meiotic aneuploidy is associated with altered morphokinetic variables of mouse oocyte maturation

STUDY QUESTION

Is there an association between morphokinetic variables of meiotic maturation and the severity of aneuploidy following in vitro maturation (IVM) in the mouse?

SUMMARY ANSWER

The severity of meiotic aneuploidy correlates with an extended time to first polar body extrusion (tPB1) and duration of meiosis I (dMI).

WHAT IS KNOWN ALREADY

Morphokinetic variables measured using time-lapse technology allow for the non-invasive evaluation of preimplantation embryo development within clinical assisted reproductive technology (ART). We recently applied this technology to monitor meiotic progression during IVM of mouse gametes. Whether there is a relationship between morphokinetic variables of meiotic progression and aneuploidy in the resulting egg has not been systematically examined at the resolution of specific chromosomes. Next-generation sequencing (NGS) is a robust clinical tool for determining aneuploidy status and has been reverse-translated in mouse blastocysts and oocytes. Therefore, we harnessed the technologies of time-lapse imaging and NGS to determine the relationship between the morphokinetics of meiotic progression and egg aneuploidy.

STUDY DESIGN SIZE DURATION

Cumulus-oocyte complexes were collected from large antral follicles from hyperstimulated CD-1 mice. Cumulus cells were removed, and spontaneous IVM was performed in the absence or presence of two doses of Nocodazole (25 or 50 nM) to induce a spectrum of spindle abnormalities and chromosome segregation errors during oocyte meiosis. Comprehensive chromosome screening was then performed in the resulting eggs, and morphokinetic variables and ploidy status were compared across experimental groups (control, n = 11; 25 nM Nocodazole, n = 13; 50 nM Nocodazole, n = 23).

PARTICIPANTS/MATERIALS SETTING METHODS

We monitored IVM in mouse oocytes using time-lapse microscopy for 16 h, and time to germinal vesicle breakdown (tGVBD), tPB1, and dMI were analyzed. Following IVM, comprehensive chromosome screening was performed on the eggs and their matched first polar bodies via adaptation of an NGS-based preimplantation genetic testing for aneuploidy (PGT-A) assay. Bioinformatics analysis was performed to align reads to the mouse genome and determine copy number-based predictions of aneuploidy. The concordance of each polar body-egg pair (reciprocal errors) was used to validate the results. Ploidy status was categorized as euploid, 1-3 chromosomal segregation errors, or ≥4 chromosomal segregation errors. Additionally, aneuploidy due to premature separation of sister chromatids (PSSC) versus non-disjunction (NDJ) was distinguished.

MAIN RESULTS AND THE ROLE OF CHANCE

We applied and validated state-of-the-art NGS technology to screen aneuploidy in individual mouse eggs and matched polar bodies at the chromosome-specific level. By performing IVM in the presence of different doses of Nocodazole, we induced a range of aneuploidy. No aneuploidy was observed in the absence of Nocodazole (0/11), whereas IVM in the presence of 25 and 50 nM Nocodazole resulted in an aneuploidy incidence of 7.69% (1/13) and 82.61% (19/23), respectively. Of the aneuploid eggs, 5% (1/20) was due to PSSC, 65% (13/20) to NDJ, and the remainder to a combination of both. There was no relationship between ploidy status and tGVBD, but tPB1 and the dMI were both significantly prolonged in eggs with reciprocal aneuploidy events compared to the euploid eggs, and this scaled with the severity of aneuploidy. Eggs with ≥4 aneuploid chromosomes had the longest tPB1 and dMI (P < 0.0001), whereas eggs with one to three aneuploid chromosomes exhibited intermediate lengths of time (P < 0.0001).

LARGE SCALE DATA

N/A.

LIMITATIONS REASONS FOR CAUTION

We used Nocodazole in this study to disrupt the meiotic spindle and induce aneuploidy in mouse oocytes. Whether the association between morphokinetic variables of meiotic progression and the severity of aneuploidy occurs with other compounds that induce chromosome segregation errors remain to be investigated. In addition, unlike mouse oocytes, human IVM requires the presence of cumulus cells, which precludes visualization of morphokinetic variables of meiotic progression. Thus, our study may have limited direct clinical translatability.

WIDER IMPLICATIONS OF THE FINDINGS

We validated NGS in mouse eggs to detect aneuploidy at a chromosome-specific resolution which greatly improves the utility of the mouse model. With a tractable and validated model system for characterizing meiotic aneuploidy, investigations into the molecular mechanisms and factors which may influence aneuploidy can be further elaborated. Time-lapse analyses of morphokinetic variables of meiotic progression may be a useful non-invasive predictor of aneuploidy severity.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by the Bill & Melinda Gates Foundation (INV-003385). Under the grant conditions of the Foundation, a Creative Commons Attribution 4.0 Generic License has already been assigned to the Author Accepted Manuscript version that might arise from this submission. The authors have no conflict of interest to disclose.

Chromatin Morphology in Human Germinal Vesicle Oocytes and Their Competence to Mature in Stimulated Cycles

The search for simple morphological predictors of oocyte quality is an important task for assisted reproduction technologies (ARTs). One such predictor may be the morphology of the oocyte nucleus, called the germinal vesicle (GV), including the level of chromatin aggregation around the atypical nucleolus (ANu)-a peculiar nuclear organelle, formerly referred to as the nucleolus-like body. A prospective cohort study allowed distinguishing three classes of GV oocytes among 135 oocytes retrieved from 64 patients: with a non-surrounded ANu and rare chromatin blocks in the nucleoplasm (Class A), with a complete peri-ANu heterochromatic rim assembling all chromatin (Class C), and intermediate variants (Class B). Comparison of the chromatin state and the ability of oocytes to complete meiosis allowed us to conclude that Class B and C oocytes are more capable of resuming meiosis in vitro and completing the first meiotic division, while Class A oocytes can resume maturation but often stop their development either at metaphase I (MI arrest) or before the onset of GV breakdown (GVBD arrest). In addition, oocytes with a low chromatin condensation demonstrated a high level of aneuploidy during the resumption of meiosis. Considering that the degree of chromatin condensation/compaction can be determined in vivo under a light microscope, this characteristic of the GV can be considered a promising criterion for selecting the best-quality GV oocytes in IVM rescue programs.

Zinc supplementation promotes oocyte maturation and subsequent embryonic development in sheep

Zinc plays a crucial role in the growth and reproductive functions of animals. Despite the positive effects of zinc that have been reported in oocytes of cows, pigs, yaks, and other animals, the influence of zinc on sheep is little known. To investigate the effect of zinc on the in vitro maturation of sheep oocytes and subsequent parthenogenesis-activated embryonic development, we added different concentrations of zinc sulfate to the in vitro maturation (IVM) culture medium. The IVM culture medium with zinc improved the maturation of sheep oocytes and the subsequent blastocyst rate after parthenogenesis activation. Notably, it also enhanced the level of glutathione and mitochondrial activity while reducing levels of reactive oxygen species. Thus, zinc addition to the IVM medium improved the quality of oocytes with a positive effect on the subsequent development of oocytes and embryos.

The Effect of In Vitro Maturation (IVM) Protocol Changes on Measures of Oocyte/Embryo Competence

Purpose: In vitro maturation (IVM) continues its evolution as new ideas are introduced with the objective of making the IVM procedure easier and more effective. This study combines ideas believed likely to improve the IVM outcome or make the IVM oocyte identification process easier. Methods: A cohort of 45 women underwent an IVM cycle in which letrozole was used with the theoretical objective of improving the competence of small antral follicles, the oocyte aspiration technique was modified to minimize the time between oocyte aspiration and oocyte identification, and blastocysts were transferred during a subsequent cycle with controlled endometrial development. Results: Measures of oocyte competence used for these prospectively followed cycles were as follows: the maturation rate was 90.5%, the fertilization rate was 92.4%, the cleavage rate was 94.6%, the usable blastulation rate per zygote was 50.2%, and the implantation rate was 34.2%. Per transfer, the biochemical pregnancy rate was 63.2%, the clinical pregnancy rate was 55.3% and the ongoing/delivered pregnancy rate at the end of the first trimester was 47.4%. The miscarriage rate for clinical pregnancies in the first trimester was 14.3% and the ongoing twinning rate was 11.1%.

Oocyte vitrification for fertility preservation following COS does not delay the initiation of neoadjuvant chemotherapy for breast cancer compared to IVM

PURPOSE

The objective of the present study was to evaluate whether oocyte vitrification following controlled ovarian stimulation (COS) for fertility preservation (FP) delays the initiation of neoadjuvant chemotherapy (NAC) for breast cancer (BC) as compared to in vitro maturation (IVM).

METHODS

We performed a retrospective cohort study including all BC patients eligible for oocyte vitrification following COS or in vitro maturation (IVM) before initiation of NAC between January 2016 and December 2020. The inclusion criteria were female patients aged between 18 and 40, with confirmed non metastatic BC, with indication of NAC, who have had oocyte retrieval for FP after COS, or IVM + / - cryopreservation of ovarian tissue (OTC). Various time points related to cancer diagnosis, FP, or chemotherapy were obtained from a medical record review.

RESULTS

A total of 197 patients with confirmed BC who had oocyte retrieval following COS (n = 57) or IVM + / - OTC (n = 140) for FP prior to NAC were included. Overall, the average time from cancer diagnosis to chemotherapy start was similar between patients having undergone COS or IVM before oocyte vitrification (37.3 ± 13.8 vs. 36. 8 ± 13.5 days; p = 0.89).

CONCLUSIONS

The indication of NAC for BC should not be considered as an impediment to urgent COS for oocyte vitrification for FP.

Outcomes of clinical in vitro maturation programs for treating infertility in hyper responders: a systematic review

Oocyte in vitro maturation (IVM) has been proposed as an alternative to conventional ovarian stimulation (COS) in subfertile women with polycystic ovary syndrome. To evaluate the effectiveness and safety of IVM compared with COS in women with predicted hyperresponse to gonadotropins, we searched the published literature for relevant studies comparing any IVM protocol with any COS protocol followed by in vitro fertilization or intracytoplasmic sperm injection. A systematic review was undertaken on 3 eligible prospective studies. Live birth rate was not significantly lower after IVM vs. COS (odds ratio [95% confidence interval] of 0.56 [0.32-1.01] overall, 0.83 [0.63-1.10] for human chorionic gonadotropin (hCG)-triggered IVM [hCG-IVM] and 0.45 [0.18-1.13] for non-hCG-triggered IVM [non-hCG-IVM]), irrespective of the stage of transferred embryos. Data from nonrandomized studies generally showed either significantly low or statistically comparable rates of live birth with IVM vs. COS. Most studies have not identified any significant difference between IVM and COS with respect to the rates of obstetric or perinatal complications, apart from a potentially higher rate of hypertensive disorders during pregnancy. The development of offspring from IVM and COS with in vitro fertilization or intracytoplasmic sperm injection appears to be similar. Additional research is needed to identify which patient populations will benefit most from IVM, to define the appropriate clinical protocol, and to develop the optimal culture system.

Development of children born after in vitro maturation with a prematuration step versus natural conception: a prospective cohort study

PURPOSE

IVM preceded by a prematuration step (capacitation [CAPA]-IVM) improves the acquisition of oocyte developmental competence and can enhance embryo quality. There is currently no follow-up data on babies born from CAPA-IVM. This study investigated developmental outcomes in children born after CAPA-IVM versus natural conception.

METHODS

This prospective cohort study was conducted at a fertility clinic in Vietnam in August/September 2019. Children born after CAPA-IVM were propensity score-matched with those born after natural conception. All parents were asked to complete the Developmental Red Flags and Ages & Stages Third Edition (ASQ-3) questionnaires.

RESULTS

A total of 46 parents (23 in each group) of 55 babies (31 CAPA-IVM and 24 natural conception) were included in the study. Baseline characteristics, including mother's age and body mass index, gestational age at delivery, and birth weight, were comparable. The mean age of children at the end of follow-up was 15 months. The overall proportion of children with any abnormal ASQ-3 score was 6.5% in the CAPA-IVM group and 20.8% in the natural conception group (p = 0.24). The proportion of children with a developmental red flag did not differ significantly between the CAPA-IVM and natural conception groups (9.7% vs. 4.2%; p = 0.80).

CONCLUSIONS

The use of CAPA-IVM did not have any significant impact on childhood physical and mental development compared with children born as a result of natural conception.

Single-cell quantitative proteomic analysis of human oocyte maturation revealed high heterogeneity in in vitro matured oocytes

Oocyte maturation is pertinent to the success of in vitro maturation (IVM), which is used to overcome female infertility, and produced over 5000 live births worldwide. However, the quality of human IVM oocytes has not been investigated at single-cell proteome level. Here, we quantified 2094 proteins in human oocytes during in vitro and in vivo maturation (IVO) by single-cell proteomic analysis and identified 176 differential proteins between IVO and germinal vesicle oocytes and 45 between IVM and IVO oocytes including maternal effect proteins, with potential contribution to the clinically observed decreased fertilization, implantation, and birth rates using human IVM oocytes. IVM and IVO oocytes showed separate clusters in principal component analysis, with higher inter-cell variability among IVM oocytes, and have little correlation between mRNA and protein changes during maturation. The patients with the most aberrantly expressed proteins in IVM oocytes had the lowest level of estradiol per mature follicle on trigger day. Our data provide a rich resource to evaluate effect of IVM on oocyte quality and study mechanism of oocyte maturation.

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Single-cell proteomic profiling of human oocytes matured in vitro and in vivo.

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Low correlation between protein and mRNA levels during human oocyte maturation.

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In vitro matured (IVM) oocytes exhibit higher heterogeneity at the proteome level.

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45 differentially expressed proteins between IVM and in vivo matured (IVO) oocytes.

The feasibility of switching from IVF to IVM combined with all-blastocyst-culture and transfer for patients with ovarian hyperstimulation syndrome tendency

OBJECTIVE

To investigate the feasibility of switching from in vitro fertilization (IVF) to in vitro maturation (IVM) combined with all-blastocyst-culture and transfer as a supplementary infertility treatment in patients with ovarian hyperstimulation syndrome (OHSS) tendency METHODS: Retrospective cohort study including 184 patients who switched from IVF and underwent 192 IVM cycles between January 2016 and December 2020. The outcomes were compared between cleavage-stage embryo transfer (group A, n = 74) and blastocyst-stage transfer (group B, n = 52) groups.

RESULTS

The OHSS rate is 0%. 66 cycles were canceled for transfer. Among the 126 transfer cycles, number of retrieved oocytes, proportion of metaphase II oocytes, cleavage rate, and proportion of high-quality embryos on day 3 post-fertilization are significantly lower in group A than that in group B. On the contrary, number of transferred embryos is significantly lower in group B than that in group A, whereas the rates of implantation, clinical pregnancy, and live births are significantly higher in group B than that in group A.

CONCLUSION

Timely switching to IVM combined with all-blastocyst-culture and transfer for patients undergoing controlled ovarian hyperstimulation and exhibiting characteristics of OHSS tendency is feasible as a supplementary infertility treatment.

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.

In Vivo and In Vitro Matured Oocytes From Mice of Advanced Reproductive Age Exhibit Alternative Splicing Processes for Mitochondrial Oxidative Phosphorylation

The mean age of women seeking infertility treatment has gradually increased over recent years. This has coincided with the emergence of in vitro maturation (IVM), a method used in assisted reproductive technology for patients with special requirements. However, when compared with conventional in vitro fertilization, IVM is associated with poor embryonic development potential and low live birth rates, thus limiting the widespread application of this technique. In this study, we performed RNA-sequencing transcriptomic assays and identified a total of 2,627 significant differentially expressed genes (DEGs) between IVM oocytes and in vivo matured oocytes from mice of advanced reproductive age. Next, Kyoto Encyclopedia of Genes and Genomes pathway analysis was used to identify the potential functions of the DEGs. The most significantly enriched pathway was oxidative phosphorylation (OXPHOS). In addition, we constructed a protein-protein interaction network to identify key genes and determined that most of the hub genes were mtDNA-encoded subunits of respiratory chain complex I. Antioxidant supplementation lead to an increase in ATP production and reduced the gene expression profile of the OXPHOS pathway in the IVM group. Moreover, alternative splicing (AS) events were identified during in vivo or in vitro oocyte maturation; data showed that skipped exons were the most frequent type of AS event. A number of genes associated with the OXPHOS pathway exhibited alterations in AS events, including Ndufa7, Ndufs7, Cox6a2, Ndufs5, Ndufb1, and Uqcrh. Furthermore, the process of IVO promoted the skipping of exon 2 in Ndufa7 and exon 3 in Ndufs7 compared with the IVM oocytes, as determined by semi-quantitative RT-PCR. Collectively, these findings provide potential new therapeutic targets for improving IVM of aged women who undergo infertility treatment.

Validating Reference Gene Expression Stability in Human Ovarian Follicles, Oocytes, Cumulus Cells, Ovarian Medulla, and Ovarian Cortex Tissue

Human ovarian cells are phenotypically very different and are often only available in limited amounts. Despite the fact that reference gene (RG) expression stability has been validated in oocytes and other ovarian cells from several animal species, the suitability of a single universal RG in the different human ovarian cells and tissues has not been determined. The present study aimed to validate the expression stability of five of the most used RGs in human oocytes, cumulus cells, preantral follicles, ovarian medulla, and ovarian cortex tissue. The selected genes were glyceraldehyde 3-phosphate dehydrogenase (GAPDH), beta-2-microglobulin (B2M), large ribosomal protein P0 (RPLP0), beta-actin (ACTB), and peptidylprolyl isomerase A (PPIA). Overall, the stability of all RGs differed among ovarian cell types and tissues. NormFinder identified ACTB as the best RG for oocytes and cumulus cells, and B2M for medulla tissue and isolated follicles. The combination of two RGs only marginally increased the stability, indicating that using a single validated RG would be sufficient when the available testing material is limited. For the ovarian cortex, depending on culture conditions, GAPDH or ACTB were found to be the most stable genes. Our results highlight the importance of assessing RGs for each cell type or tissue when performing RT-qPCR analysis.

A review on the relationship between anti-mullerian hormone and fertility in treating young breast cancer patients

Despite the fact that the long-term survival rate of breast cancer patients had been significantly improved owing to the systemic breast cancer therapies, there are still some side effects such as amenorrhea and fertility retention to be resolved, leaving it an important thing to understand the possible side effects on fertility and fertility preservation strategies while undergoing breast cancer treatment, due to the fact that most young patients hope to become pregnant and have children after breast cancer treatment. With anti-müllerian hormone (AMH) being the most sensitive marker for predicting ovarian function in young premenopausal women with breast cancer, this review is aimed to provide the additional guidance for clinical application of AMH by exploring the impacts of AMH on the fertility of young breast cancer patients, the relationship between AMH and metabolism, and the relationship between BRAC gene mutation and fertility protection strategies.

A threshold concentration of FSH is needed during IVM of ex vivo collected human oocytes

PURPOSE

To investigate the effect of different FSH concentrations on human oocyte maturation in vitro and its impact on gene expression of key factors in the surrounding cumulus cells.

METHODS

The study included 32 patients who underwent unilateral oophorectomy for ovarian tissue cryopreservation (OTC) (aged 28 years on average). Immature oocytes were collected from surplus medulla tissue. A total of 587 immature oocytes were divided into three categories according to the size of the cumulus mass: large (L-COCs), small (S-COCs), and naked oocytes (NOs), and submitted to 44-h IVM with one of the following concentrations of recombinant FSH: 0 IU/L, 20 IU/L, 40 IU/L, 70 IU/L, or 250 IU/L. After IVM, oocyte nuclear maturation stage and diameter were recorded. The relative gene expression of FSHR, LHCGR, and CYP19A1 in cumulus cells before (day 0; D0) and after IVM were evaluated.

RESULTS

Addition of 70 or 250 IU/L FSH to the IVM medium improved oocyte nuclear maturation compared to 0, 20, and 40 IU/L FSH by upregulating LHCGR and downregulating FSHR in the cumulus cells.

CONCLUSION

FSH improved oocyte nuclear maturation at concentrations above 70 IU/L suggesting a threshold for FSH during IVM of ex vivo collected human oocytes from small antral follicles. Moreover, current results for the first time highlight that FSH function in vitro is mediated via cumulus cells by downregulating FSHR and upregulating LHCGR, which was also observed when the immature oocytes progressed in meiosis from the GV to the MII stage.

Early pregnancy loss in patients with polycystic ovary syndrome after IVM versus standard ovarian stimulation for IVF/ICSI

STUDY QUESTION

Is the incidence of early pregnancy loss (EPL) in patients with polycystic ovary syndrome (PCOS) higher after IVM of oocytes than after ovarian stimulation (OS) for IVF/ICSI?

SUMMARY ANSWER

Women with PCOS who are pregnant after fresh embryo transfer have a higher probability of EPL following IVM, but after frozen embryo transfer (FET), no significant difference in the incidence of EPL was observed following IVM compared to OS.

WHAT IS KNOWN ALREADY

There is conflicting evidence in the current literature with regard to the risk of EPL after IVM of oocytes when compared with OS. Because of the limited sample size in previous studies, the use of different IVM systems and the possible bias introduced by patient characteristics and treatment type, firm conclusions cannot be drawn.

STUDY DESIGN, SIZE, DURATION

This was a retrospective cohort study evaluating 800 women, with a diagnosis of infertility and PCOS as defined by Rotterdam criteria, who had a first positive pregnancy test after fresh or FET following IVM or OS between January 2010 and December 2017 in a tertiary care academic medical centre.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Pregnancies after non-hCG triggered IVM following a short course of highly purified human menopausal gonadotropin were compared with those after conventional OS. The primary outcome was EPL, defined as a spontaneous pregnancy loss before 10 weeks of gestation.

MAIN RESULTS AND THE ROLE OF CHANCE

In total, 329 patients with a positive pregnancy test after IVM and 471 patients with a positive pregnancy test after OS were included. Women who were pregnant after IVM were younger (28.6 ± 3.4 years vs 29.3 ± 3.6 years, P = 0.005) and had higher serum anti-Mullerian hormone levels (11.5 ± 8.1 ng/ml vs 7.2 ± 4.1 ng/ml, P < 0.001) compared to those who were pregnant after OS. The distribution of PCOS phenotypes was significantly different among women in the IVM group compared to those in the OS group and women who were pregnant after OS had previously suffered EPL more often (28% vs 17.6%, P = 0.003). EPL was significantly higher after fresh embryo transfer following IVM compared to OS (57/122 (46.7%) vs 53/305 (17.4%), P < 0.001), while the results were comparable after FET (63/207 (30.4%) vs 60/166 (36.1%), respectively, P = 0.24). In the multivariate logistic regression analysis evaluating fresh embryo transfer cycles, IVM was the only independent factor (adjusted odds ratio (aOR) 4.24, 95% CI 2.44-7.37, P < 0.001)) significantly associated with increased odds of EPL. On the other hand, when the same model was applied to FET cycles, the type of treatment (IVM vs OS) was not significantly associated with EPL (aOR 0.73, 95% CI 0.43-1.25, P = 0.25).

LIMITATIONS, REASONS FOR CAUTION

The current data are limited by the retrospective nature of the study and the potential of bias due to unmeasured confounders.

WIDER IMPLICATIONS OF THE FINDINGS

The increased risk of EPL after fresh embryo transfer following IVM may point towards inadequate endometrial development in IVM cycles. Adopting a freeze-all strategy after IVM seems more appropriate. Future studies are needed to ascertain the underlying cause of this observation.

STUDY FUNDING/COMPETING INTEREST(S)

The Clinical IVM research has been supported by research grants from Cook Medical and Besins Healthcare. All authors declared no conflict of interest.

TRIAL REGISTRATION NUMBER

N/A.

Enhancing the scope of in vitro maturation for fertility preservation: transvaginal retrieval of immature oocytes during endoscopic gynaecological procedures

STUDY QUESTION

Could in vitro maturation (IVM) following transvaginal oocyte retrieval during gynaecological surgery (IVM-surgery) be an effective and safe strategy for fertility preservation?

SUMMARY ANSWER

IVM-surgery on unstimulated ovaries is a novel option that can be considered for fertility preservation for women requiring gynaecological surgery, but more research is needed to identify appropriate patients who may benefit and to determine the cost-effectiveness of such an approach.

WHAT IS KNOWN ALREADY

IVM followed by oocyte/embryo cryopreservation has been useful as a safe reproductive strategy for some infertile women.

STUDY DESIGN, SIZE, DURATION

This prospective cohort study comprised 158 consecutive women with polycystic ovary syndrome (PCOS) who underwent laparoscopy or hysteroscopy for other reasons and had concomitant transvaginal oocyte retrieval followed by IVM between 2014 and 2016.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 158 women with anovulatory PCOS who underwent IVM-surgery in our infertility centre were recruited for this study. Matured IVM oocytes obtained from these women were either freshly fertilized and subsequently frozen at the blastocyst stage (fresh oocyte group, n = 46) or the oocytes were frozen (frozen oocyte group, n = 112) for fertility preservation followed by later thawing for insemination and cleavage embryo transfer (ET) (n = 33). The following outcomes were then evaluated: embryological data, clinical pregnancy rate, live birth rate (LBR), neonatal outcomes, post-operative complications and post-operative ovarian function.

MAIN RESULTS AND THE ROLE OF CHANCE

Among all the women who underwent IVM-surgery, the clinical pregnancy rate and LBR per initiated IVM cycle were 9.5% (15/158) and 6.9% (11/158), respectively. Women (40.6%, 20/33) who underwent the procedure with frozen-thawed oocytes (oocyte survival rate, 83.0%) obtained a high quality of cleaved embryos. In the fresh oocyte group, the clinical pregnancy rate and LBR per ET cycle were 69.2 and 53.8%, respectively. In the frozen oocyte group, the clinical pregnancy rate and LBR per ET cycle were 28.6 and 19.1%, respectively. No adverse neonatal outcomes were recorded. IVM-surgery was not associated with post-operative complications, a longer hospital stay, or impaired ovarian function.

LIMITATIONS, REASONS FOR CAUTION

Because of the small sample size and the low utilization rate and cost-effectiveness per retrieval, the present findings should be interpreted with caution, and further studies are needed for the long-term follow-up of live births.

WIDER IMPLICATIONS OF THE FINDINGS

This strategy can also help patients with normal ovulation to obtain available oocytes and embryos for cryopreservation and subsequent use.

STUDY FUNDING/COMPETING INTEREST(S)

This research was supported by the Joint Research Fund for Overseas Natural Science of China (No. 31429004), the National Key Research and Development Program of China (No. 2017YFC1002000, 2017YFC1001504, 2016YFC1000302), the Ministry of Science and Technology of China Grants (No. 2014CB943203), the Chinese Society of Reproductive Medicine Fund (No. 16020400656) and the National Natural Science Foundation of China (No. 81300456). All the authors have nothing to disclose in terms of conflicts of interest.

TRIAL REGISTRATION NUMBER

chictr-ONC-17011861.

Live births following fertility preservation using in-vitro maturation of ovarian tissue oocytes

STUDY QUESTION

Can oocytes extracted from excised ovarian tissue and matured in vitro be a useful adjunct for urgent fertility preservation (FP)?

SUMMARY ANSWER

Ovarian tissue oocyte in-vitro maturation (OTO-IVM) in combination with ovarian tissue cryopreservation (OTC) is a valuable adjunct technique for FP.

WHAT IS KNOWN ALREADY

Despite the impressive progress in the field, options for FP for cancer patients are still limited and, depending on the technique, clinical outcome data are still scarce.

STUDY DESIGN, SIZE, DURATION

This was a retrospective cohort study conducted at a university hospital-affiliated fertility clinic between January 2012 and May 2019.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The study included 77 patients who underwent unilateral oophorectomy for OTC. Cumulus-oocyte complexes (COCs) obtained during ovarian tissue processing were matured in vitro for 28-42 h. Oocytes reaching metaphase II stage were vitrified or inseminated for embryo vitrification.

MAIN RESULTS AND THE ROLE OF CHANCE

Overall, 1220 COCs were collected. The mean oocyte maturation rate was 39% ± 23% (SD). There were 64 patients who had vitrification of oocytes (6.7 ± 6.3 oocytes per patient). There were 13 patients who had ICSI of mature oocytes after IVM, with 2.0 ± 2.0 embryos vitrified per patient. Twelve patients have returned to the clinic with a desire for pregnancy. For seven of these, OTO-IVM material was thawed. Two patients had OTO-IVM oocytes warmed, with survival rates of 86% and 60%. After ICSI, six oocytes were fertilised in total, generating three good quality embryos for transfer, leading to a healthy live birth for one patient. In five patients, for whom a mean of 2.0 ± 0.8 (SD) embryos had been vitrified, seven embryos were warmed in total: one embryo did not survive the warming process; two tested genetically unsuitable for transfer; and four were transferred in separate cycles to three different patients, resulting in two healthy babies. In this small series, the live birth rate per patient after OTO-IVM, ICSI and embryo transfer was 43%.

LIMITATIONS, REASONS FOR CAUTION

The retrospective study design and the limited sample size should be considered when interpreting results.

WIDER IMPLICATIONS OF THE FINDINGS

The results of the study illustrate the added value of OTO-IVM in combination with OTC. We report the first live birth following the use of this appended technique combined with oocyte vitrification.

STUDY FUNDING/COMPETING INTEREST(S)

No external funding was used for this study. M.D.V. reports honoraria for lectures in the last 2 years from MSD and Ferring, outside the submitted work, as well as grant support from MSD. The other authors have nothing to declare.

TRIAL REGISTRATION NUMBER

N/A.

In Vitro Fertilization for Polycystic Ovarian Syndrome

In vitro fertilization is indicated for infertile women with polycystic ovarian syndrome (PCOS) after unsuccessful treatment with ovulation induction agents or in women deemed high-risk of multiple gestations who are ideal candidates for single embryo transfers. PCOS patients are at increased risk of ovarian hyperstimulation syndrome; therefore, attention should be made in the choice of in vitro fertilization treatment protocol, dose of gonadotropin utilized, and regimen to achieve final oocyte maturation. Adopting these strategies in addition to close monitoring may significantly reduce the ovarian hyperstimulation syndrome risk. Future developments may improve pregnancy outcomes and decrease complications in PCOS women undergoing fertility treatment.

Effect of Human Testicular Cells Conditioned Medium on In Vitro Maturation and Morphology of Mouse Oocytes

Background

Testicular cell conditioned medium (TCCM) has been shown to induce female germ cell development in vitro from embryonic stem cells (ESCs). Testicular cells (TCs) secrete a variety of growth factors such as growth differentiation factor-9 (GDF-9), bone morphogenetic protein 4 (BMP-4), stem cell factor (SCF), leukemia inhibitory factor (LIF), and other, that could improve oocyte maturation. Here we have investigated the effect of human TCCM (hTCCM) on in vitro maturation (IVM) and morphology of mouse oocytes.

Materials and Methods

In this experimental study, 360 germinal vesicle (GV) oocytes were obtained from NMRI mice, aged 4-6 weeks that had received 5 IU pregnant mare's serum gonadotropin (PMSG) 48 hours before. GV oocytes were subjected to IVM. 120 GV oocytes were cultured in each medium; hTCCM as the test group, DMEM + 20%FBS as the control group and Ham’s F10 + HFF medium as the sham group. The rates of the IVM and perivi- telline space (PVS) changes were recorded at 8, 16 and 24 hours after culture. The metaphase II (MII) oocytes were subjected for in vitro fertilization (IVF) and the fertilization rate was evaluated after 1, 2, and 3 days.

Results

There was a significant difference between the maturation rates in hTCCM (31.67% MII) and the control [0% MII, P<0.05, (7.5% MI, 52.5% deg. and 40%GV)] groups but there was not a significant difference between the maturation rates in hTCCM and the sham group (53.33% MII, P>0.05). IVF success rate for MII oocytes obtained from IVM in the hTCCM group was 28.94% (n=11). Our data showed that hTCCM is an effective medium for GV oocyte growth and maturation compared to the control medium.

Conclusion

Our findings show that TCCM supports oocyte IVM in mice and affect oocyte morphology.

In-vitro maturation versus IVF: a cost-effectiveness analysis

RESEARCH QUESTION

How do costs and effects of in-vitro maturation (IVM) compare to IVF in women with a high antral follicle count (AFC)?

DESIGN

This cost-effectiveness analysis (CEA) was based on data of a previous retrospective cohort study at IVFMD, My Duc Hospital, Ho Chi Minh City, Vietnam. Between July 2015 and December 2017, 608 women underwent IVM and 311 women IVF. The effectiveness measure for the CEA was cumulative live birth rate (LBR) after one completed cycle including subsequent cryo-cycles within 12 months of inclusion. Data were collected on resource use related to treatment, medication and pregnancy from the case report forms. The mean costs and effects, average cost differences and incremental cost-effectiveness ratios (ICER) were calculated using non-parametric bootstrap resampling to assess the effect of uncertainty in the estimates.

RESULTS

Cumulative LBR after one completed cycle were 239/608 (39.3%) in the IVM group versus 155/311 (49.8%) in the IVF group (adjusted odds ratio 0.52, 95% confidence interval [CI] 0.30-0.89). Ovarian hyperstimulation syndrome (OHSS) did not occur in the IVM group versus 11/311 (3.5%) in the IVF group. The mean costs per couple were €4300 (95% CI €1371-18,798) for IVM and €6493 (95% CI €2204-20,136) for IVF. The ICER per additional live birth with IVF was €20,144 (95% CI €9116-50,418). Results were robust over a wide range of assumptions.

CONCLUSIONS

IVM is less expensive than IVF in women with a high AFC undergoing treatment with assisted reproductive technology, while leading to a slightly lower effectiveness in terms of cumulative LBR.

Rescue In Vitro Maturation in Polycystic Ovarian Syndrome Patients Undergoing In Vitro Fertilization Treatment who Overrespond or Underrespond to Ovarian Stimulation: Is It A Viable Option? A Case Series Study

Background

This study intends to present the role of rescue in vitro maturation (IVM) in polycystic ovarian syn- drome (PCOS) patients undergoing in vitro fertilization (IVF) treatment who have inappropriate responses to ovarian stimulation.

Materials and Methods

This was a retrospective case series study of five PCOS patients undergoing IVF treatment considered for cycle cancellation due to increased risk of ovarian hyperstimulation syndrome (OHSS) as group A or poor response to ovarian stimulation as group B. Patients in group A had high oestradiol levels and recruitment of high numbers of small/intermediate sized follicles that did not meet the criteria for human chorionic gonadotropin (hCG) triggering. Patients in group B responded inadequately to hormonal stimulation despite high gonadotropin dosage. Treatment was changed to rescue IVM cycles after the patients provided consent.

Results

In group A, three IVF patients deemed to have high chances of developing OHSS as evidenced by high oestradiol levels were converted to IVM. A total of the 58/68 oocytes retrieved were mature or matured in vitro. There were 26 cleaving embryos obtained. Two patients had live births and one patient suffered a miscarriage. In group B, rescue IVM was implemented in two patients due to poor ovarian response (POR). A total of 22/26 oocytes retrieved were mature or matured in vitro. There were 13 cleaving embryos obtained. One patient had a live birth, whilst the other suffered a miscarriage.

Conclusion

Rescue IVM could be a viable option in PCOS patients undergoing IVF treatment who are unable to safely meet the criteria for hCG triggering due to overresponse to ovarian stimulation or ovarian resistance to high doses of stimulation. Conversion to IVM can still result in reasonable oocyte retrieval and lead to clinical pregnancy and live births without the risks of OHSS.

Association between mild stimulated IVF/M cycle and early embryo arrest in sub fertile women with/without PCOS

BACKGROUND

The in vitro maturation (IVM) technique has physical and financial benefits, but a lower efficiency and outcome that is still unclear whether it is related to polycystic ovary syndrome (PCOS) itself or the IVM procedure. In this study, we analyzed the clinical and laboratory outcomes of an optimized IVM protocol in patients with and without PCOS. We also discussed the possible reasons for early embryo arrest in the IVM cycle.

METHODS

This prospective study involved 58 PCOS patients and 56 non-PCOS patients who underwent mild stimulated IVF combined IVM (IVF/M) cycles. The clinical and laboratory outcomes were compared between the two groups. Also, metaphase II (MII) oocytes were obtained after IVM from the two groups, and in vivo MII oocytes randomly collected from IVF patients were examined for mitochondrial function using a laser scanning confocal microscope (LSCM). The aneuploidy rate for arrested cleavage embryos from IVM and IVF oocytes were screened using Next Generation Sequencing (NGS).

RESULTS

Mildly stimulated IVF/M resulted in cumulative clinical pregnancy and implantation rates (40.2, 28.7% in the PCOS group vs. 41.9, 36% in the non-PCOS group), respectively. The blastocyst formation rates were comparable (28% vs. 28.2%) in PCOS and non-PCOS groups, respectively. Using LSCM, there was a significant decrease in the mitochondrial membrane potential of IVM oocytes compared with the control IVF oocytes (P < 0.001), but no significant difference between the PCOS and non-PCOS groups. The NGS showed that the aneuploidy rates were comparable (75, 75, and 66.6%) in IVM-PCOS, IVM-non-PCOS, and control IVF arrested embryos, respectively.

CONCLUSIONS

The mildly stimulated IVF/M protocol produced acceptable clinical outcomes in PCOS and non-PCOS patients. IVM itself rather than the PCOS condition adversely affected the embryo development through its effect on mitochondrial function, which appeared to be a possible cause for the embryo arrest in the IVM cycles rather than chromosomal aneuploidy.

Implications of Assisted Reproductive Technologies for Pregnancy Outcomes in Mammals

Development of assisted reproductive technologies has been driven by the goals of reducing the incidence of infertility, increasing the number of offspring from genetically elite animals, facilitating genetic manipulation, aiding preservation and long-distance movement of germplasm, and generating research material. Superovulation is associated with reduced fertilization rate and alterations in endometrial function. In vitro production of embryos can have a variety of consequences. Most embryos produced in vitro are capable of establishing pregnancy and developing into healthy neonatal animals. However, in vitro production is associated with reduced ability to develop to the blastocyst stage, increased incidence of failure to establish pregnancy, placental dysfunction, and altered fetal development. Changes in the developmental program mean that some consequences of being produced in vitro can extend into adult life. Reduced competence of the embryo produced in vitro to develop to the blastocyst stage is caused largely by disruption of events during oocyte maturation and fertilization. Conditions during embryo culture can affect embryo freezability and competence to establish pregnancy after transfer. Culture conditions, including actions of embryokines, can also affect the postnatal phenotype of the resultant progeny.

Mechanistic insights into the reduced developmental capacity of in vitro matured oocytes and importance of cumulus cells in oocyte quality determination

In vitro maturation of oocytes is a promising assisted reproductive technology (ART) for infertility treatment, although it is still not a routine technique for human ART due to reduced embryonic development. The aim of the present study was to clarify the possible reasons for reduced capacity of in vitro matured oocytes. Our results showed that the oocytes matured in vitro displayed increased abnormal mitochondrial distribution, reduced mitochondrial membrane potential, and increased reactive oxygen species levels when compared to in vivo matured oocytes. These results were not different in oocytes matured in vitro with or without cumulus cells. Notably, in vitro matured oocytes displayed increased mitochondrial DNA numbers probably due to functional compensation. In vitro matured oocytes showed significantly lower activation and embryonic development rates, and their ability to produce Ca²⁺ oscillations was much lower in response to parthenogenetic activation, especially in oocytes matured in vitro without cumulus cells with nearly half of them failing to produce calcium waves upon strontium chloride stimulation. These data are important for understanding the reasons for reduced developmental potential of in vitro matured oocytes and the importance of cumulus cells for oocyte quality.

Live birth after in vitro maturation versus standard in vitro fertilisation for women with polycystic ovary syndrome: protocol for a non-inferiority randomised clinical trial

INTRODUCTION

Polycystic ovary syndrome (PCOS) is the first common cause of anovulatory infertility. Currently, in vitro fertilisation (IVF) is recommended when conventional attempts have failed. In vitro maturation (IVM) of human oocytes is an emerging treatment option in infertile women with PCOS. It is a patient-friendly intervention, avoiding the risk of ovarian hyperstimulation syndrome, which is a serious complication of controlled ovarian stimulation in the standard IVF procedure. We plan a randomised controlled trial (RCT) to evaluate whether IVM is non-inferior to the standard IVF for live birth in women with PCOS.

METHODS AND ANALYSIS

This is a single-centre, open-label, non-inferiority RCT performed in a large reproductive medicine centre in China. Infertile women with PCOS will be randomised to receive either IVM or standard IVF in a 1:1 treatment ratio after informed consent. IVF procedures used in our study are all standard treatments and other standard-assisted reproductive technologies will be similar between the two groups. The primary outcome is ongoing pregnancy leading to live birth within 6 months of the first oocyte retrieval cycle after randomisation. Pregnancy outcome, maternal safety and obstetric and perinatal complications will be secondary outcomes. The planned sample size is 350 (175 per group).

ETHICS AND DISSEMINATION

Ethical permission was acquired from the Ethics Committee of Peking University Third Hospital. The results will be issued to publications through scientific journals and conference reports.

TRIAL REGISTRATION NUMBER

NCT03463772.

[Oncofertility and breast cancer]

Over the past decades, progresses in oncology have improved the recovery rates after numerous malignant diseases, including breast cancer, that strike young adults in childbearing age. Quality of life of young cancer survivors has become a major issue. However, anticancer therapies can have a detrimental impact on fertility. It is now well-established that all patients should receive information about the fertility risks associated with their cancer treatment and the fertility preservation options available. These techniques aim to limit the negative impact of chemotherapy on the ovaries or to preserve gametes before treatment. Currently, oocyte or embryo freezing after controlled ovarian hyperstimulation represents the most effective method for preserving female fertility. Over the past years innovative protocols of ovarian stimulation have been developed to enable breast cancer patients to undergo oocyte or embryo cryopreservation irrespective of the phase of the cycle or without exogenous follicle-stimulating hormone related increase in serum estradiol levels. When controlled ovarian hyperstimualtion cannot be implemented, other techniques such as cryopreservation of ovarian cortex, in vitro maturation or the use of GnRH agonists may be proposed. However, it is important to inform patients that all these fertility preservation techniques do not represent a guarantee of pregnancy.

Does a web-based decision aid improve informed choice for fertility preservation in women with breast cancer (DECISIF)? Study protocol for a randomised controlled trial

INTRODUCTION

Chemotherapy may cause infertility in young survivors of breast cancer. Various fertility preservation techniques increase the likelihood of survivors becoming genetic mothers. Disclosure of cancer diagnosis may impact decision making about fertility preservation. This protocol will develop and test the effectiveness of a web-based decision aid for helping women with breast cancer to make well-informed choices about fertility preservation.

METHODS AND ANALYSIS

This study will be conducted in three phases using mixed methods. In phase I, the aim is to develop a web-based patient decision aid (PDA) in French with a steering committee and using a focus group of five women already treated for breast cancer. In phase II, the face validity of the decision aid will be assessed using questionnaires. In phase III, the PDA will be assessed by a two-arm randomised controlled trial. This will involve a quantitative evaluation of the PDA in clinical practice comparing the quality of the decision-making process between usual care and the PDA. The primary outcome will be informed choice and its components. The secondary outcomes will be decisional conflict and anxiety. Data will be collected during and after an oncofertility consultation. Phase III is underway. Since September 2018, 52 participants have been enrolled in the study and have completed the survey. We expect to have results by February 2020 for a total of 186 patients.

ETHICS AND DISSEMINATION

This study protocol was approved by the Ouest V Research Ethics Board. Results will be spread through peer-reviewed publications, and reported at suitable meetings.

TRIAL REGISTRATION NUMBER

The ClinicalTrials.gov registry .(NCT03591848).

Transvaginal ovarian drilling followed by controlled ovarian stimulation from the next day improves ovarian response for the poor responders with polycystic ovary syndrome during IVF treatment: a pilot study

BACKGROUND

Poor response patients with PCOS who are not susceptible to gonadotropin stimulation are more likely to have canceled cycles or poor clinical outcomes during IVF treatment. However, some limitations exist in the present therapies. In this study, we evaluated the effects of using the transvaginal ovarian drilling (TVOD) followed by controlled ovarian stimulation (COS) from the second day of these poor responders.

METHODS

During IVF, 7 poor responders with PCOS and 28 PCOS patients (14 normal and 14 high responders) were recruited. All patients received COS with the gonadotropin-releasing hormone antagonist protocol. For the poor responders, after undergoing 10 to 14 days of ovulation induction with no response, the TVOD was applied and then ovarian stimulation was performed from the next day at the same gonadotropin dose. Serum samples during COS and follicular fluid samples from the dominant follicles on the oocyte pick-up (OPU) day in all three groups were collected. Besides, follicular fluid from small follicles (diameter < 1 cm) in the normal and high responders on the OPU day and those in the poor responders on the TVOD day were gathered. Hormonal levels were examined in all samples using immunometric assays.

RESULTS

All the poor responders restored ovary response after receiving TVOD. There was no significant difference in the stimulation duration, total gonadotrophin dose used and the clinical outcomes among the three groups. The body mass index, serum and follicular levels of anti-Müllerian hormone (AMH) and testosterone in poor responders were higher than those in the other two groups, and the application of TVOD significantly decreased the levels of AMH and testosterone in both serum and follicular fluid.

CONCLUSIONS

TVOD followed by ovulation induction from the next day is effective and convenient for poor responders with PCOS. The decline of AMH and testosterone resulted from TVOD may be the main reason resulting in the recovery of ovary sensitivity to gonadotropins. The small sample size is the primary limitation of this study, future studies using a large population cohort and monitoring the long-term outcomes of this strategy will be required.

TRIAL REGISTRATION

ChiCTR1900023612. Registered 04 June 2019-Retrospectively registered.

Luteinizing Hormone Action in Human Oocyte Maturation and Quality: Signaling Pathways, Regulation, and Clinical Impact

The ovarian follicle luteinizing hormone (LH) signaling molecules that regulate oocyte meiotic maturation have recently been identified. The LH signal reduces preovulatory follicle cyclic nucleotide levels which releases oocytes from the first meiotic arrest. In the ovarian follicle, the LH signal reduces cyclic nucleotide levels via the CNP/NPR2 system, the EGF/EGF receptor network, and follicle/oocyte gap junctions. In the oocyte, reduced cyclic nucleotide levels activate the maturation promoting factor (MPF). The activated MPF induces chromosome segregation and completion of the first and second meiotic divisions. The purpose of this paper is to present an overview of the current understanding of human LH signaling regulation of oocyte meiotic maturation by identifying and integrating the human studies on this topic. We found 89 human studies in the literature that identified 24 LH follicle/oocyte signaling proteins. These studies show that human oocyte meiotic maturation is regulated by the same proteins that regulate animal oocyte meiotic maturation. We also found that these LH signaling pathway molecules regulate human oocyte quality and subsequent embryo quality. Remarkably, in vitro maturation (IVM) prematuration culture (PMC) protocols that manipulate the LH signaling pathway improve human oocyte quality of cultured human oocytes. This knowledge has improved clinical human IVM efficiency which may become a routine alternative ART for some infertile patients.

Fertility Treatment Options for Women With Polycystic Ovary Syndrome

Polycystic ovary syndrome is the most common endocrinological disorder in women of reproductive age. It is commonly associated with anovulatory subfertility, for which there are a range of treatment options available to help them conceive. These options are given in a step-wise manner with an appropriate selection of patients to maximise success rates with minimal complications. This review discusses the importance and involvement of multidisciplinary care when offering treatment to women with subfertility. Multidisciplinary care gives an excellent opportunity to identify, assess risk, and potentially prevent future morbidities and complications while treating women for fertility issues. We have also summarised the various options available for fertility treatment: pharmacological treatments, nonpharmacological intervention, and assisted reproductive technology.

Biphasic in vitro maturation (CAPA-IVM) specifically improves the developmental capacity of oocytes from small antral follicles

PURPOSE

To investigate the effectiveness of a biphasic IVM culture strategy at improving IVM outcomes in oocytes from small follicles (< 6 mm) compared with routine Standard IVM in patients with polycystic ovaries.

METHODS

This prospective pilot study was performed in 40 women with polycystic ovaries whose oocytes were randomized to two IVM culture methods. Patients received a total stimulation dose of 450 IU rFSH. Cumulus-oocyte complexes (COCs) from follicles < 6 mm and ≥ 6 mm were retrieved and cultured separately in either a prematuration medium with c-type natriuretic peptide followed by IVM (CAPA-IVM), or STD-IVM. Primary outcomes were maturation rate, embryo quality, and the number of vitrified day 3 embryos per patient.

RESULTS

Use of the CAPA-IVM system led to a significant improvement in oocyte maturation (p < 0.05), to a doubling in percentage of good and top-quality day 3 embryos per COC, and to an increased number of vitrified day 3 embryos (p < 0.001), compared to STD IVM. Oocytes from follicles < 6 mm benefited most from CAPA-IVM, showing a significant increase in the amount of good and top-quality embryos compared to STD IVM. CAPA-IVM yielded significantly (p < 0.0001) less GV-arrested oocytes and larger oocyte diameters (p < 0.05) than STD IVM.

CONCLUSIONS

CAPA-IVM brings significant improvements in maturation and embryological outcomes, most notably to oocytes from small antral follicles (< 6 mm), which can be easily retrieved from patients with a minimal ovarian stimulation. The study demonstrates the robustness and transferability of the CAPA-IVM method across laboratories and populations.

Obstetrical, neonatal, and long-term outcomes of children conceived from in vitro matured oocytes

OBJECTIVE

To investigate the obstetrical, neonatal, and long-term outcomes of in vitro maturation (IVM) compared with conventional in vitro fertilization (IVF) in women with polycystic ovarian syndrome (PCOS).

DESIGN

Matched retrospective case-control study.

SETTING

University fertility clinic.

PATIENT(S)

One hundred eighty-four patients undergoing IVM were compared with 366 patients undergoing conventional IVF. All had PCOS and were matched for patient age, gestational age at birth, and the number of fetuses.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Obstetrics, neonatal outcomes, and childhood medical problems and development.

RESULT(S)

Women's mean age at oocytes retrieval was 32.6 ± 2.9 years. Children's mean age was 7.5 ± 2.3 years. There were no differences in the frequency of obstetrical and neonatal outcomes between the two groups. No difference was found in birth weights between the two groups. The incidence of congenital anomalies was similar between the groups (4.3% in IVM group vs. 4.1% in IVF group). No significant difference was observed between the two groups in the frequency and duration of hospitalization during childhood. Growth developmental status of both groups was within normal range.

CONCLUSION(S)

In a matched setting between IVM and IVF babies born from women with PCOS, no significant increased risk associated with IVM was been identified after a mean follow-up of 7.5 years.

Thymoquinone reduces intracytoplasmic oxidative stress and improves epigenetic modification in polycystic ovary syndrome mice oocytes, during in-vitro maturation

Although in-vitro maturation (IVM) of oocytes has been presented as an alternative treatment to traditional stimulated in-vitro fertilization, the culture condition can be improved by natural antioxidants. Thus, we investigated the protective effect of Thymoquinone (TQ) during IVM in the polycystic ovary syndrome (PCOS) mice model. The induction of PCOS was made by dehydroepiandrosterone via subcutaneous injection, in prepubertal female B6D2F1-mice. After 21 days later, germinal vesicle (GV)-stage-oocytes were extracted and incubated in IVM media containing 0, 1.0, 10.0, and 100.0 μM of TQ. To assess fertilization and blastulation rates, after 22-24 hr, the treated oocytes were fertilized in-vitro with epididymal spermatozoa. Some other oocytes were evaluated for maturation, epigenetic, and oxidative stress markers. Similarly, the mRNA expression of epigenetic enzymes genes (Dnmt1 and Hdac1), three maternally derived genes (Mapk, CyclinB, and Cdk1) and apoptosis-related genes (Bax and Bcl2) were assessed. Our results showed that the maturation, fertilization, and blastulation rates were significantly higher in the 10.0 μM TQ-treated group compared with the untreated group and likewise with in-vivo matured oocytes. The Bax expression was reduced in 10.0 μM TQ matured oocytes, but Bcl2, Dnmt1, Hdac1, Cdk1, and Mapk were upregulated in this group compared to other groups. Furthermore, dimethylation of histone-3 at lysine-9 (H3K9m2) and DNA methylation were significantly increased whereas H4K12 acetylation (H4K12ac) was decreased in the 10.0 μM TQ-treated group in comparison with control and in-vivo matured oocytes. Therefore, our results are suggesting that 10.0 μM TQ may enhance the developmental competence of PCOS oocytes via the modulation of oxidative stress and epigenetic alterations.

Anti-Müllerian Hormone in Fertility Preservation: Clinical and Therapeutic Applications

Anti-Müllerian hormone (AMH) is a member of the transforming growth factor (TGF)-beta family and a key regulator of sexual differentiation and folliculogenesis. While the serum AMH level has been used in reproductive medicine as a biomarker of quantitative ovarian reserve for more than 20 years, new potential therapeutic applications of recombinant AMH are emerging, notably in the field of oncofertility. Indeed, it is well known that chemotherapy, used to treat cancer, induces ovarian follicular depletion and subsequent infertility. Animal models have been used widely to understand the effects of different cytotoxic agents on ovarian function, and several hypotheses regarding chemotherapy gonadotoxicity have been proposed, that is, it might have a direct detrimental effect on the primordial follicles constituting the ovarian reserve and/or on the pool of growing follicles secreting AMH. Recently, a new mechanism of chemotherapy-induced follicular depletion, called the “burn-out effect,” has been proposed. According to this theory, chemotherapeutic agents may lead to a massive growth of dormant follicles which are then destroyed. As AMH is one of the factors regulating the recruitment of primordial follicles from the ovarian reserve, recombinant AMH administration concomitant with chemotherapy might limit follicular depletion, therefore representing a promising option for preserving fertility in women suffering from cancer. This review reports on the potential usefulness of AMH measurement as well as AMH’s role as a therapeutic agent in the field of female fertility preservation.

The Place of In Vitro Maturation in Assisted Reproductive Technology

In vitro maturation (IVM) is an assisted reproductive technology (ART) whereby immature cumulus-oocyte complexes are collected and matured in vitro, without need for controlled ovarian stimulation and ovulation triggering. Advantages of IVM over in vitro fertilization (IVF) include mild or no stimulation, lower medication costs and less patient burden. However, early clinical outcomes with IVM were suboptimal. More recently, clinical studies reported live birth rates after IVM of about 40%. New IVM culture systems are being used to improve the efficacy of IVM. These have been in widespread use for animals for many years and are now showing promise in the clinical setting. Patients more likely to benefit from IVM over IVF include those at risk of OHSS (e.g. women with polycystic ovary syndrome), when the time for ovarian stimulation is limited, or where sustained elevations of estradiol are contraindicated (e.g. oncofertility indications). The main barrier to use of IVM to date was its relative efficacy compared with IVF, and there have also been concerns over the health of infants born following IVM. However, no differences in congenital abnormalities between IVM and other ARTs have been identified. In addition, there is a lack of both experience and standardized protocols. Strategies to overcome barriers to the use of IVM include better training for clinicians, more and better funded research in the field, and improved recognition of IVM by fertility specialists. Overall, IVM offers a valuable alternative for ART in select patient populations. New approaches to IVM appear to have the potential to achieve pregnancy outcomes equivalent to those after IVF. Increasing the use of IVM in the future can be achieved with improved training and education for fertility specialists, and increased funding for IVM research, with the ultimate goal of improving fertility outcomes.

Improvement of embryonic development and clinical outcomes of germinal vesicle stage oocytes using a microvibration culture system

In vitro maturation (IVM) has evolved as a clinical treatment option in assisted reproductive technology. However, the poor developmental potential of germinal vesicle (GV)-stage oocytes is still suboptimal. This study's objective was to evaluate the effect of a microvibration culture system (MVC) during IVM and/or in vitro culture (IVC) on the clinical outcomes and the embryonic development potential of human GV-stage oocytes collected from human chorionic gonadotropin (HCG)-primed IVM and fertilization-embryo transfer (IVM/F-ET) cycles of patients with polycystic ovaries (PCO). A total of 206 HCG-primed IVM/F-ET cycles were divided into four groups according to the microvibration and static culture system applied during IVM and/or IVC: Group SS (static system during both IVM and IVC); Group SV (static system during IVM alternated with microvibration system during IVC); Group VS (microvibration system during IVM alternated with static system during IVC), and Group VV (microvibration system during both IVM and IVC). The results indicate that the rates of in vitro MII oocytes per cycle, fertilization, and cleavage were not significantly different between the groups. The rate of good-quality embryos in Group SV tended to be higher than the rate in Groups SS and VS, but there was no significant difference between Group SS and Group SV. Clinical pregnancy, implantation, and live birth rates of Groups SV and VS were slightly higher than those of Group SS. However, the rate of good-quality embryos with at least six cells on day 4, the clinical pregnancy, implantation, and live births in Group VV were significantly higher than those in Group SS. These results indicate that, compared with the static culture system, the MVC system applied for both IVM and IVC seems to improve the clinical outcomes and the quality of embryos of GV oocytes derived from HCG-primed IVM/F-ET cycles in PCO patients. Abbreviations: PCO: polycystic ovaries; HCG: human chorionic gonadotropin; GV: germinal vesicle; MII: metaphase II; IVM: in vitro maturation; IVF: in vitro fertilization; IVC: in vitro culture: MVC: microvibration culture; SC: static culture; ICSI: intracytoplasmic sperm injection; IVM/F-ET: IVM and fertilization-embryo transfer; AMH: anti-Mullerian hormone; OHSS: ovarian hyperstimulation syndrome.

Comparison of GnRH agonist and hCG for priming in vitro maturation cycles in cancer patients undergoing urgent fertility preservation

In vitro maturation (IVM) of oocytes retrieved at germinal vesicle or Metaphase I stage, followed by vitrification of Metaphase II (MII) oocytes, has recently emerged as an option for urgent fertility preservation (FP). Priming is usually achieved with an injection of hCG, 10,000 IU, 36 hours before retrieval. This study aimed to assess a new method of priming, using GnRH agonists, and compare it to hCG, in cancer patients undergoing urgent FP. From 2009 to 2015, 373 cancer patients underwent MII oocyte cryopreservation after IVM cycles primed either with GnRHa (triptorelin 0.2 mg) (n = 138) or hCG (10,000 IU) (n = 235). Patients’ characteristics were comparable between the two groups. The number of COC retrieved was significantly higher in the GnRHa group (9.1 ± 6.8 versus 7.7 ± 5.5 oocytes, p = 0.04). However, the maturation rates (59 ±25% versus 64 ±26%, p = 0.07, respectively), and the total number of MII oocytes frozen (5.2 ±4.2 versus 4.9 ±4.0, p = 0.6, respectively) were similar between the GnRha and hCG groups. We did not find any difference between GnRHa and hCG priming for IVM. GnRHa priming is more physiological since it stimulates endogenous FSH and LH activity, and is well suited for FP in hormone-sensitive cancers and urgent cases.

In vitro maturation in subfertile women with polycystic ovarian syndrome undergoing assisted reproduction

BACKGROUND

Polycystic ovarian syndrome (PCOS) occurs in 4% to 7% of all women of reproductive age and 50% of women presenting with subfertility. Subfertility affects 15% to 20% of couples trying to conceive. A significant proportion of these women ultimately need assisted reproductive technology (ART). In vitro fertilisation (IVF) is one of the assisted reproduction techniques employed to raise the chances of achieving a pregnancy. For the standard IVF technique, stimulating follicle development and growth before oocyte retrieval is essential, for which a large number of different methods combining gonadotrophins with a gonadotrophin-releasing hormone (GnRH) agonist or antagonist are used. In women with PCOS, the supra-physiological doses of gonadotrophins used for controlled ovarian hyperstimulation (COH) often result in an exaggerated ovarian response, characterised by the development of a large cohort of follicles of uneven quality, retrieval of immature oocytes, and increased risk of ovarian hyperstimulation syndrome (OHSS). A potentially effective intervention for women with PCOS-related subfertility involves earlier retrieval of immature oocytes at the germinal-vesicle stage followed by in vitro maturation (IVM). So far, the only data available have derived from observational studies and non-randomised clinical trials.

OBJECTIVES

To assess the effectiveness and safety of IVM followed by IVF or ICSI versus conventional IVF or ICSI among women with PCOS undergoing assisted reproduction.

SEARCH METHODS

This is the second update of this review. We performed the search on 17 April 2018.The search was designed with the help of the Cochrane Gynaecology and Fertility Group Information Specialist, for all published and unpublished randomised controlled trials (RCTs).We searched the the Cochrane Gynaecology and Fertility Group Specialised Register of controlled trials, CENTRAL via the Cochrane Central Register of Studies Online, MEDLINE, Embase, CINAHL, and the trial registers for ongoing and registered trials and the Open Grey database for grey literature from Europe. We made further searches in the National Institute for Health and Care Excellence (NICE) fertility assessment and treatment guidelines. We handsearched reference lists of relevant systematic reviews and RCTs, together with PubMed and Google for any recent trials that have not yet been indexed in the major databases.

SELECTION CRITERIA

All RCTs on the intention to perform IVM before IVF or ICSI compared with conventional IVF or ICSI for subfertile women with PCOS, irrespective of language and country of origin.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies, assessed risk of bias, extracted data from studies, and attempted to contact the authors of studies for which data were missing. Our primary outcomes were live birth per woman randomised and miscarriage. We performed statistical analysis using Review Manager 5. We assessed evidence quality using GRADE methods.

MAIN RESULTS

We found two RCTs suitable for inclusion in the review and six ongoing trials that have not yet reported results. Both included studies were published as abstracts in international conferences.Both studies were at unclear or high risk of bias for most of the seven domains assessed. Common problems were unclear reporting of study methods and lack of blinding. The main limitations in the overall quality of the evidence were high risk of bias and serious imprecision.There were no data on the primary outcomes of this review, namely live birth per woman randomised and miscarriage.Both studies reported clinical pregnancy rate: there was evidence of an effect between IVM and IVF, favouring the former (odds ratio 3.10, 95% confidence interval 1.06 to 9.00; 71 participants; 2 studies; I² = 0%; very low-quality evidence). The incidence of OHSS was zero in both studies in both groups.There were no data for the other outcomes specified in this review.

AUTHORS' CONCLUSIONS

Though promising data on the in vitro maturation (IVM) technique have been published, unfortunately there is still no evidence from properly conducted randomised controlled trials upon which to base any practice recommendations regarding IVM before in vitro fertilisation (IVF) or intracytoplasmic sperm injection for women with polycystic ovarian syndrome. Regarding our secondary outcomes, very low-quality evidence showed that clinical pregnancy was higher with IVM when compared to IVF, whereas the incidence of ovarian hyperstimulation syndrome was zero in both studies in both groups. We are awaiting the results of six ongoing trials and eagerly anticipate further evidence from good-quality trials in the field.

Maturational gene upregulation and mitochondrial activity enhancement in mouse in vitro matured oocytes and using granulosa cell conditioned medium

The high miscarriage rates that result following transfer of embryos derived from in vitro maturation (IVM) of oocytes necessitate improvements in the processes involved. This study aimed to improve the quality of in vitro matured oocytes using granulosa cell conditioned medium (GCCM) as the culture medium. In this work, germinal vesicle (GV)-stage oocytes from NMRI mice were collected and cultured using three types of culture medium: Base medium (BM) (control), 50% granulosa cell conditioned medium (GCCM50) and 100% GCCM (GCCM100). After IVM, the mitochondria activity potential and viability of metaphase II (MII) oocytes were evaluated by JC-1 and trypan blue staining, respectively. Maturational gene expression levels of CyclinB1, Cdk1 and Gdf9 in the control, GCCM50 and GCCM100 samples were analyzed using real-time polymerase chain reaction (PCR). The viability rate of in vitro matured oocytes was highest in the GCCM50 group. JC-1 staining showed that GCCM50 enhances mitochondrial activity more than the other groups (P < 0.05). Gene expression levels of Cdk1 and Gdf9 were higher in the group with GCCM50 treatment, than in the control and GCCM100 groups (P < 0.05), while the expression level of CyclinB1 did not differ among the groups. The results indicated that a 50% concentration of GCCM in combination with BM components enhanced MII and viability rates and mitochondria activity of mouse immature oocytes.

Novel Concepts for Inducing Final Oocyte Maturation in In Vitro Fertilization Treatment

Infertility affects one in six of the population and increasingly couples require treatment with assisted reproductive techniques. In vitro fertilization (IVF) treatment is most commonly conducted using exogenous FSH to induce follicular growth and human chorionic gonadotropin (hCG) to induce final oocyte maturation. However, hCG may cause the potentially life-threatening iatrogenic complication "ovarian hyperstimulation syndrome" (OHSS), which can cause considerable morbidity and, rarely, even mortality in otherwise healthy women. The use of GnRH agonists (GnRHas) has been pioneered during the last two decades to provide a safer option to induce final oocyte maturation. More recently, the neuropeptide kisspeptin, a hypothalamic regulator of GnRH release, has been investigated as a novel inductor of oocyte maturation. The hormonal stimulus used to induce oocyte maturation has a major impact on the success (retrieval of oocytes and chance of implantation) and safety (risk of OHSS) of IVF treatment. This review aims to appraise experimental and clinical data of hormonal approaches used to induce final oocyte maturation by hCG, GnRHa, both GnRHa and hCG administered in combination, recombinant LH, or kisspeptin. We also examine evidence for the timing of administration of the inductor of final oocyte maturation in relationship to parameters of follicular growth and the subsequent interval to oocyte retrieval. In summary, we review data on the efficacy and safety of the major hormonal approaches used to induce final oocyte maturation in clinical practice, as well as some novel approaches that may offer fresh alternatives in future.

The use of in vitro maturation in stimulated antagonist in vitro fertilization cycles of normo-hyperresponder women due to arrested follicular development: A rescue procedure

Objective

To evaluate the impact of rescue in vitro maturation (IVM) on the clinical outcomes of women with arrested follicular development in stimulated in vitro fertilization (IVF) cycles.

Materials and Methods

This is a retrospective review of 13 patients who were evaluated as normo-hyperresponders for ovarian stimulation. The main outcome measure was the clinical pregnancy and livebirth rates. The purpose of gonadotropin stimulation in patients undergoing IVF is to retrieve multiple oocytes by avoiding multifetal gestation and Ovarian Hyperstimulation syndrome (OHSS). The ovarian response to stimulation ranges from poor response to OHSS, which is related to the follicular number and the dose of the gonadotropins used. However, in some cycles of normo-hyperresponder women, follicular development decelerates or ceases. Close follow-up in a daily manner and increasing the dose of gonadotropins did not change the follicular arrest. This clinical situation has two edges; one is cycle cancellation, which has undesired psychological outcomes for women and the IVF team, and second one is the prolongation of the IVF cycle. For such circumstances, IVM may be a valuable option. Stimulated IVF cycles were converted to IVM as a rescue IVM procedure following detailed informed consent of the women who were close to cycle cancellation.

Results

Thirteen 13 IVM cycles and their clinical outcomes are presented. Six women achieved pregnancies, but only 4 delivered 5 healthy live born. The other two women had biochemical loss during follow-up.

Conclusion

Based on the data obtained, it can be concluded that gonadotropin-stimulated cycles with follicular arrest at the edge of cancellation can be shifted to rescue IVM procedures with reasonable clinical outcomes.

Live birth rate after human chorionic gonadotropin priming in vitro maturation in women with polycystic ovary syndrome

BACKGROUND

In vitro maturation (IVM) has some advantages over conventional in vitro fertilization (IVF), particularly in polycystic ovary syndrome (PCOS) where the risk of ovarian hyperstimulation is high. We studied the live birth rate in a large series of PCOS women undergoing human chorionic gonadotropin (hCG)-priming IVM.

METHODS

This retrospective study included women with PCOS aged 18-42 years undergoing IVM with hCG priming. We reported live birth rate after the first embryo transfer and cumulative live birth rate from embryos obtained in the IVM cycle. We also performed logistic regression to assess which factors predicted number of oocytes and live birth.

RESULTS

We included 921 women (age 28.9±3.5 years, body mass index 21.8±3.1 kg/m2, infertility duration 3.7±2.6 years, 81% primary infertility, 88% first IVF attempt, 94% ovulation induction failure). Live birth rate after the first embryo transfer was 31.7%, with a cumulative live birth rate from the cycle of 33.7%. High anti-Müllerian hormone levels predicted a high number of oocytes and a high oocyte maturation rate while the opposite was the case when luteinizing hormone levels were high.

CONCLUSIONS

In women with PCOS, hCG priming IVM was feasible and resulted in acceptable live birth rates.

In vitro maturation

In vitro maturation (IVM) is an in vitro fertilisation (IVF) technique modified to collect immature oocytes from antral follicles, with the final stages of meiosis completed during in vitro culture. The primary benefit of IVM is that it reduces gonadotrophin stimulation in the patient, thereby eliminating the risk of ovarian hyperstimulation syndrome (OHSS) in high-risk patients such as those with polycystic ovaries (PCO) and polycystic ovary syndrome (PCOS). IVM has additional benefits for fertility preservation, particularly in oncofertility patients. IVM research has progressed in recent years to significantly improve success rates and to provide evidence of safety in terms of neonatal and childhood outcomes. More recently, pre-maturation protocols and the discovery of new culture media additives have demonstrated potential to maximise maturation and oocyte developmental competence. In this chapter, we discuss current methodologies used in clinics routinely performing IVM, target patient populations and areas of future research that may improve IVM success.

Genome stability of bovine in vivo-conceived cleavage-stage embryos is higher compared to in vitro-produced embryos

STUDY QUESTION

Is the rate and nature of chromosome instability (CIN) similar between bovine in vivo-derived and in vitro-cultured cleavage-stage embryos?

SUMMARY ANSWER

There is a major difference regarding chromosome stability of in vivo-derived and in vitro-cultured embryos, as CIN is significantly lower in in vivo-derived cleavage-stage embryos compared to in vitro-cultured embryos.

WHAT IS KNOWN ALREADY

CIN is common during in vitro embryogenesis and is associated with early embryonic loss in humans, but the stability of in vivo-conceived cleavage-stage embryos remains largely unknown.

STUDY DESIGN, SIZE, DURATION

Because human in vivo preimplantation embryos are not accessible, bovine (Bos taurus) embryos were used to study CIN in vivo. Five young, healthy, cycling Holstein Friesian heifers were used to analyze single blastomeres of in vivo embryos, in vitro embryos produced by ovum pick up with ovarian stimulation (OPU-IVF), and in vitro embryos produced from in vitro matured oocytes retrieved without ovarian stimulation (IVM-IVF).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Single blastomeres were isolated from embryos, whole-genome amplified and hybridized on Illumina BovineHD BeadChip arrays together with the bulk DNA from the donor cows (mothers) and the bull (father). DNA was also obtained from the parents of the bull and from the parents of the cows (paternal and maternal grandparents, respectively). Subsequently, genome-wide haplotyping and copy-number profiling was applied to investigate the genomic architecture of 171 single bovine blastomeres of 16 in vivo, 13 OPU-IVF and 13 IVM-IVF embryos.

MAIN RESULTS AND THE ROLE OF CHANCE

The genomic stability of single blastomeres in both of the in vitro-cultured embryo cohorts was severely compromised (P < 0.0001), and the frequency of whole chromosome or segmental aberrations was higher in embryos produced in vitro than in embryos derived in vivo. Only 18.8% of in vivo-derived embryos contained at least one blastomere with chromosomal anomalies, compared to 69.2% of OPU-IVF embryos (P < 0.01) and 84.6% of IVM-IVF embryos (P < 0.001).

LARGE SCALE DATA

Genotyping data obtained in this study has been submitted to NCBI Gene Expression Omnibus (GEO; accession number GSE95358).

LIMITATIONS REASONS FOR CAUTION

There were two main limitations of the study. First, animal models may not always reflect the nature of human embryogenesis, although the use of an animal model to investigate CIN was unavoidable in our study. Second, a limited number of embryos were obtained, therefore more studies are warranted to corroborate the findings.

WIDER IMPLICATIONS OF THE FINDINGS

Although CIN is also present in in vivo-developed embryos, in vitro procedures exacerbate chromosomal abnormalities during early embryo development. Hence, the present study highlights that IVF treatment compromises embryo viability and should be applied with care. Additionally, our results encourage to refine and improve in vitro culture conditions and assisted reproduction technologies.

STUDY FUNDING/COMPETING INTEREST(S)

The study was funded by the Agency for Innovation by Science and Technology (IWT) (TBM-090878 to J.R.V. and T.V.), the Research Foundation Flanders (FWO; G.A093.11 N to T.V. and J.R.V. and G.0392.14 N to A.V.S. and J.R.V.), the European Union's FP7 Marie Curie Industry-Academia Partnerships and Pathways (IAPP, SARM, EU324509 to J.R.V., T.V., O.T, A.D., A.S. and A.K.) and Horizon 2020 innovation programme (WIDENLIFE, 692065 to J.R.V., O.T., T.V., A.K. and A.S.). M.Z.E., J.R.V. and T.V. are co-inventors on a patent application ZL913096-PCT/EP2014/068315-WO/2015/028576 ('Haplotyping and copy-number typing using polymorphic variant allelic frequencies'), licensed to Cartagenia (Agilent Technologies).

Oocyte in vitro maturation: A sytematic review

In vitro maturation (IVM) is one of the most controversial aspects of assisted reproductive technology. Although it has been studied extensively, it is still not a conventional treatment option and is accepted as an alternative treatment. However, studies have shown that IVM can be used in almost all areas where in vitro fertilization (IVF) is used and it has a strong place in fertility protection and Ovarian Hyperstimulation syndrome management. The aim of this systematic review was to address all aspects of the current knowledge of IVM treatment together with the evolution of IVM and IVF.

Medical techniques of fertility preservation in the male and female

Therapeutic advances in many medical fields have led to the need to consider patient quality of life after curative medico-surgical treatments for malignancy. Thus, it has become a major issue for young patients to preserve the ability to become "genetic" parents, with their own gametes. While the preservation of male fertility has been an established technique for more than 30 years, it is only in the last decade that progress in cryopreservation techniques has allowed surgeons to offer successful oocyte and ovarian tissue cryobanking. However, in addition to the still experimental nature of some fertility preservation techniques, this practice also raises many ethical and moral questions.

A pre-in vitro maturation medium containing cumulus oocyte complex ligand-receptor signaling molecules maintains meiotic arrest, supports the cumulus oocyte complex and improves oocyte developmental competence

STUDY QUESTION

Can a pre-in vitro maturation (pre-IVM) medium containing signaling molecules rather than chemical/pharmaceutical agents, sustain meiotic arrest and improve developmental competence of in vitro matured oocytes in CF1 outbred mice?

SUMMARY ANSWER

A short 2 h period of pre-IVM prevents spontaneous meiotic resumption, improves mitochondria activity in subsequently matured oocytes, and increases developmental competence, pregnancy rate and implantation of resulting embryos.

WHAT IS KNOWN ALREADY

Spontaneous resumption of meiosis in vitro is detrimental for oocyte developmental competence. Pre-IVM systems that prevent spontaneous meiotic resumption with chemical/pharmaceutical agents are a promising approach to improving IVM oocyte competence; however, the success of these methods has proven to be inconsistent.

STUDY DESIGN, SIZE, DURATION

This study consisted of a series of experiments using cumulus oocyte complexes (COC) derived from outbred mice following ovarian stimulation. The study was designed to examine if a novel, ligand/receptor-based pre-IVM treatment could sustain meiotic arrest in vitro and improve oocyte developmental competence, compared to control IVM. Two pre-IVM durations (2 h and 24 h) were evaluated, and the effect of the mitochondrial stimulator PQQ during 24 h pre-IVM was studied.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Murine (outbred CF1) immature COC were cultured in vitro in the presence of C-type natriuretic peptide (CNP) (30 nM), estradiol (100 nM), FSH (1 × 10-4 IU/ml) and bone morphogenic protein 15 (BMP15) (100 ng/ml) for 2 h or 24 h prior to IVM. Meiotic status during pre-IVM and IVM was analyzed using orcein staining, and functionality of gap junction communication was confirmed using the functional gap junction inhibitor carbenoxolone (CBX). Oocytes exposed to pre-IVM treatment were compared to control oocytes collected on the same day from the same females and undergoing standard IVM. Developmental competence and embryo viability was assessed by oocyte mitochondrial activity and ATP concentration, in vitro embryo development following IVF and in vitro culture, blastocyst cell number and allocation, embryo morphokinetics, and embryo transfer. Differences were determined to be significant when P < 0.05.

MAIN RESULTS AND THE ROLE OF CHANCE

Both a short (2 h) and long (24 h) pre-IVM period successfully prevented spontaneous resumption of meiosis. Moreover, gap junctions remained open during the pre-IVM period, as shown by the resumption of meiosis (95.9 ± 2.1%) in the presence of CBX during pre-IVM. A 2 h pre-IVM treatment improved blastocyst development after 96 h of culture per cleaved embryo compared to control (71.9 ± 7.4% versus 53.3 ± 6.2%, respectively), whereas a longer 24 h pre-IVM had no effect on development. A short 2 h period of pre-IVM increased mitochondrial activity in mature oocytes. On the contrary, mitochondrial activity was reduced in mature oocytes following 24 h of arrest and IVM. Treatment of arrested COC with pyrroloquinoline quinone (PQQ) during the 24 h pre-IVM period successfully maintained mitochondrial activity equal to control. However, PQQ was not able to improve blastocyst development compared to pre-IVM 24 h without PQQ. Moreover, ATP concentration in mature oocytes following pre-IVM and/or IVM, did not differ between treatments. A 2 h pre-IVM period prior to IVM improved pregnancy rate following transfer to recipient females. Implantation was also improved after transfer of embryos derived from oocytes arrested for either 2 h or 24 h prior to IVM, compared to control IVM derived embryos (41.9 ± 9%, 37.2 ± 9.5% and 17.2 ± 8.3%, respectively), although fetal development did not differ.

LIMITATIONS, REASONS FOR CAUTION

Slower meiotic resumption and enhanced mitochondrial activity likely contribute to improved developmental competence of oocytes exposed to pre-IVM for 2 h, but further experiments are required to identify specific mechanisms. Maintaining oocytes in meiotic arrest for 24 h with this approach could be a potential window to improve oocyte quality. However, an initial attempt to utilize this period of arrest to manipulate quality with PQQ, a mitochondrial stimulator, did not improve oocyte competence.

WIDER IMPLICATIONS OF THE FINDINGS

IVM could be an attractive clinical alternative to conventional IVF, with reduced time, cost and reliance on high doses of exogenous hormones to stimulate follicle growth, thus eliminating ovarian hyperstimulation syndrome (OHSS). Currently IVM is not widely used as it results in reduced embryo development and lower pregnancy outcomes compared to embryos produced from in vivo matured oocytes. Our approach to IVM, incorporating a ligand/receptor pre-IVM period, could improve human oocyte quality following IVM leading to routine adoption of this patient friendly technology. In addition, our methodology of pre-IVM containing signaling molecules rather than chemical/pharmaceutical agents may prove to be more consistent at improving oocyte quality than those focusing only on cAMP modulation with pharmacological agents. Finally, a reliable method of maintaining oocytes in meiotic arrest in vitro provides a novel window of opportunity in which the oocyte may be manipulated to address specific physiological deficiencies prior to meiotic resumption.

LARGE SCALE DATA

N/A.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by the Colorado Center for Reproductive Medicine (CCRM, Lone Tree, Colorado USA). We declare no conflict of interest.