Machine learning for predicting elective fertility preservation outcomes

This retrospective study applied machine-learning models to predict treatment outcomes of women undergoing elective fertility preservation. Two-hundred-fifty women who underwent elective fertility preservation at a tertiary center, 2019-2022 were included. Primary outcome was the number of metaphase II oocytes retrieved. Outcome class was based on oocyte count (OC): Low (≤ 8), Medium (9-15) or High (≥ 16). Machine-learning models and statistical regression were used to predict outcome class, first based on pre-treatment parameters, and then using post-treatment data from ovulation-triggering day. OC was 136 Low, 80 Medium, and 34 High. Random Forest Classifier (RFC) was the most accurate model (pre-treatment receiver operating characteristic (ROC) area under the curve (AUC) was 77%, and post-treatment ROC AUC was 87%), followed by XGBoost Classifier (pre-treatment ROC AUC 74%, post-treatment ROC AUC 86%). The most important pre-treatment parameters for RFC were basal FSH (22.6%), basal LH (19.1%), AFC (18.2%), and basal estradiol (15.6%). Post-treatment parameters were estradiol levels on trigger-day (17.7%), basal FSH (11%), basal LH (9%), and AFC (8%). Machine-learning models trained with clinical data appear to predict fertility preservation treatment outcomes with relatively high accuracy.

Embryos from vitrified vs. fresh oocytes in an oocyte donation program: a comparative morphokinetic analysis

OBJECTIVE

To compare the morphokinetic patterns of human embryos originating from vitrified oocytes (VITRI group) with those derived from freshly collected oocytes (CONTROL group) in oocyte donation cycles.

DESIGN

This is a retrospective observational study.

SETTING

Embryolab Fertility Clinic, Embryology Lab, Thessaloniki, Greece.

PATIENT(S)

The study included embryos from 421 vitrified oocytes from 58 oocyte donation cycles and 196 fresh oocytes from 23 oocyte donation cycles.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Key time parameters, dynamic events, fertilization rates, degeneration rates, cleavage rates, blastocyst rates, pregnancy rates, clinical pregnancy rates, implantation rates, and live birth rates were estimated.

RESULTS

The mean survival rate of vitrified oocytes was 92.58% (±7.42%). Fertilization rates were significantly different between the 2 groups (VITRI group: 71.92% ± 20.29% and CONTROL group: 80.65% ± 15.22%) whereas the degeneration, cleavage, blastocyst, pregnancy, clinical pregnancy, ongoing pregnancy, implantation, and live birth rates were not significantly different between embryos derived from fresh or vitrified oocytes. Time-lapse analysis showed no significant difference in any key time parameter. However, when examining dynamic parameters, first cell cycle (CC1) (t2 - tPB2: from the second polar body extrusion (tPB2) up to 2 cells (t2)) showed a significant difference whereas CC1a (t2 - tPNf: from fading of the pronuclei (tPNf) up to 2 cells (t2)) was at the threshold of significance.

CONCLUSION(S)

CC1 in vitrified oocytes exhibited a comparatively slower progression in contrast to fresh oocytes. Conversely, CC1a in vitrified oocytes demonstrated faster progression compared with fresh oocytes. It is worth noting that these temporary deviations had minimal impact on the subsequent development. Despite the clinical outcomes showing a decrease in the vitrified group, none of them reached statistical significance. This lack of significance could be attributed to the limited sample size of the study.

The Effect of Open and Closed Oocyte Vitrification Systems on Embryo Development: A Systematic Review and Network Meta-Analysis

Background/Objectives: Open and closed vitrification systems are commonly employed in oocyte cryopreservation; however, there is limited evidence regarding a comparison of their separate impact on oocyte competence. This study uniquely brings to the literature, data on the effect of open versus closed vitrification systems on laboratory and clinical outcomes, and the effect of cooling and warming rates. Methods: A systematic search of the literature was performed using the databases PubMed/MEDLINE and the Cochrane Central Library, limited to articles published in English up to January 2023. A network meta-analysis was conducted comparing each vitrification system versus fresh oocytes. Results: Twenty-three studies were included. When compared to fresh oocytes, both vitrification devices resulted in lower fertilization rates per MII oocyte retrieved. When comparing the two systems in terms of survival rates, no statistically significant difference was observed. However, interestingly open systems resulted in lower cleavage and blastocyst formation rates per 2 pronuclear (2PN) oocyte compared to fresh controls, while at the same time no statistically significant difference was detected when comparing closed devices with fresh oocytes. Conclusions: In conclusion, closed vitrification systems appear to exert a less detrimental impact on the oocytes' competence, which is reflected in the blastocyst formation rates. Proof of superiority of one system versus the other may lead to standardization, helping to ultimately determine optimal practice in oocyte vitrification.

Investigating the impact of vitrification on bovine ovarian tissue morphology, follicle survival, and transcriptomic signature

PURPOSE

Ovarian tissue cryopreservation is vital for fertility preservation, yet its effect on ovarian tissue follicle survival and transcriptomic signature requires further investigation. This study delves into the effects of vitrification on tissue morphology, function, and transcriptomic changes, helping to find possibilities for vitrification protocol improvements.

METHODS

Ovarian cortex from 19 bovine animals were used to conduct pre- and post-vitrification culture followed by histological assessment, immunohistochemistry, and TUNEL assay. Follicles' functionality was assessed for viability and growth within the tissue and in isolated cultures. RNA-sequencing of ovarian tissue was used to explore the transcriptomic alterations caused by vitrification.

RESULTS

Follicle density, cell proliferation, and DNA damage in ovarian stroma were unaffected by vitrification. However, vitrified cultured tissue exhibited reduced follicle density of primordial/primary and antral follicles, while freshly cultured tissue manifested reduction of antral follicles. Increased stromal cell proliferation and DNA damage occurred in both groups post-culture. Isolated follicles from vitrified tissue exhibited similar viability to fresh follicles until day 4, after which the survival dropped. RNA-sequencing revealed minor effects of vitrification on transcriptomic signatures, while culture induced significant gene expression changes in both groups. The altered expression of WNT and hormonal regulation pathway genes post-vitrification suggests the molecular targets for vitrification protocol refinement.

CONCLUSION

Vitrification minimally affects tissue morphology, follicle density, and transcriptomic signature post-thawing. However, culture revealed notable changes in vitrified tissue samples, including reduced follicle density, decreased isolated follicle survival, and alteration in WNT signalling and ovarian hormonal regulation pathways, highlighted them as possible limitations of the current vitrification protocol.

Frozen autologous and donor oocytes are associated with differences in clinical and neonatal outcomes compared with fresh oocytes: a Society for Assisted Reproductive Technology Clinic Outcome Reporting System Analysis

Objective

To study the clinical and neonatal outcomes of embryos derived from frozen oocytes relative to fresh oocytes in both autologous and donor oocyte cycles after fresh embryo transfer (ET).

Design

This is a retrospective cohort study using the Society for Assisted Reproductive Technology Clinic Outcome Reporting System database between 2014 and 2015.

Setting

The Society for Assisted Reproductive Technology Clinic Outcome Reporting System database was used to identify autologous and donor oocyte cycles that resulted in a fresh ET during 2014 and 2015.

Patients

There were 154,706 total cycles identified that used embryos derived from fresh or frozen oocytes and resulted in a fresh ET, including 139,734 autologous oocyte cycles and 14,972 donor oocyte cycles.

Interventions

Generalized linear regression models were used to compare the clinical and neonatal outcomes of frozen oocytes relative to fresh oocytes. Models were adjusted for maternal age, body mass index, smoking status, parity, infertility diagnosis, number of embryos transferred, and preimplantation genetic testing. An additional sensitivity analysis was performed to examine singleton pregnancies separately.

Main Outcome Measures

The live birth (LB) rate was the primary outcome. Secondary outcomes include pregnancy and birthweight outcomes.

Results

Differences in clinical and neonatal outcomes between fresh and frozen-thawed oocytes after fresh ET were observed. Specifically, our study found a higher incidence of high-birthweight infants after the use of frozen oocytes relative to fresh oocytes in both autologous oocytes (12.5% [frozen] vs. 4.5% [fresh], adjusted risk ratio [aRR] 2.67, 95% confidence interval [CI] 1.65-4.3) and donor oocyte cycles (6.2% [frozen] vs. 4.6% [fresh], aRR 1.42, 95% CI 1.1-1.83). This finding remained true when the analysis was restricted to singleton gestations only for both groups: autologous (17.3% [frozen] vs. 7.1% [fresh], aRR 2.77, 95% CI 1.74-4.42) and donor oocytes (9.4% [frozen] vs. 7.8% [fresh], aRR 1.38, 95% CI 1.07-1.77). Additionally, we observed a decrease in LB (aRR 0.81, 95% CI 0.77-0.85); clinical pregnancy (aRR 0.83, 95% CI 0.8-0.87); and an increase in biochemical pregnancy loss (aRR 1.22, 95% CI 1.05-1.43) after the use of frozen oocytes in donors, but not autologous cycles.

Conclusions

Our findings of an increased incidence of high-birthweight infants after the transfer of embryos derived from frozen oocytes in both autologous and donor oocyte cycles raise questions about oocyte vitrification and deserve further study. Additionally, the finding of a decreased likelihood of LB with frozen-donor oocytes compared with fresh donor oocytes is an important finding, especially because more patients are seeking to use frozen oocytes in their donor egg cycles. Future research should be directed toward these findings to optimize the use of frozen oocytes in clinical practice.

Planned oocyte cryopreservation: the state of the ART

The objective of this review is to provide an update on planned oocyte cryopreservation. This fertility preservation method increases reproductive autonomy by allowing women to postpone childbearing whilst maintaining the option of having a biological child. Oocyte cryopreservation is no longer considered experimental, and its use has increased dramatically in recent years as more women delay childbearing for personal, professional and financial reasons. Despite increased usage, most patients who have undergone oocyte cryopreservation have not yet warmed their oocytes. Most women who cryopreserve oocytes wait years to use them, and many never use them. Studies have demonstrated that oocyte cryopreservation results in live birth rates comparable with IVF treatment using fresh oocytes, and does not pose additional safety risks to offspring. Based on current evidence, cryopreserving ≥20 mature oocytes at <38 years of age provides a 70% chance of one live birth. However, larger studies from a variety of geographic locations and centre types are needed to confirm these findings. Additional research is also needed to determine the recommended age for oocyte cryopreservation, recommended number of oocytes to cryopreserve, return and discard/non-use rates, cost-effectiveness, and how best to distribute accurate and up-to-date information to potential patients.

Alterations in the expression pattern of some epigenetic-related genes and microRNAs subsequent to oocyte cryopreservation

MicroRNAs (miRNAs) are small non-encoding RNAs that actively regulate biological and physiological processes, and play an important role in regulating gene expression in all cells, especially in most animal cells, including oocytes and embryos. The expression of miRNAs at the right time and place is crucial for the oocyte's maturation and the embryo's subsequent development. Although assisted reproductive techniques (ART) have helped to solve many infertility problems, they cause changes in the expression of miRNA and genes in oocytes and preimplantation embryos, and the effect of these changes on the future of offspring is unknown, and has caused concerns. The relevant genomic alterations commonly imposed on embryos during cryopreservation may have potential epigenetic risks. Understanding the biological functions of miRNAs in frozen maturated oocytes may provide a better understanding of embryonic development and a comparison of fertility conservation in female mammals. With the development of new techniques for genomic evaluation of preimplantation embryos, it has been possible to better understand the effects of ART. The results of various articles have shown that freezing of oocytes and the cryopreservation method are effective for the expression of miRNAs and, in some cases, cause changes in the expression of miRNAs and epigenetic changes in the resulting embryo. This literature review study aimed to investigate the effects of oocyte cryopreservation in both pre-maturation and post-maturation stages, the cryopreservation method and the type of cryoprotectants (CPA) used on the expression of some epigenetic-related genes and miRNAs.

Long-term storage of vitrified oocytes does not affect pregnancy and live birth rates: analysis of 5362 oocyte donation cycles

RESEARCH QUESTION

Does long-term storage of vitrified oocytes affect laboratory and reproductive outcomes after intracytoplasmic sperm injection?

DESIGN

Retrospective cohort study including 41,783 vitrified-warmed oocytes from 5362 oocyte donation cycles between 2013 and 2021. Five categories of storage time were established to analyse its effect on clinical and reproductive outcomes (≤1 year [reference group], 1-2 years, 2-3 years, 3-4 years and >4 years).

RESULTS

The mean number of warmed oocytes was 8.0 ± 2.5 oocytes. Oocyte storage time ranged from 3 days to 8.2 years (mean: 0.7 ± 0.9). Mean oocyte survival (90.2% ± 14.7% overall) did not significantly decrease with longer storage time after adjusting for confounders (88.9% for time >4 years, P = 0.963). A linear regression model did not show a significant effect of oocyte storage time on fertilization rate (about 70% in all time categories) (P > 0.05). Reproductive outcomes after the first embryo transfer were statistically comparable across storage times (P > 0.05 for all categories). Longer term oocyte storage (>4 years) did not affect the chances of clinical pregnancy (OR 0.700, 95% CI 0.423 to 1.158, P = 0.2214) or live birth (OR 0.716, 95% CI 0.425 to 1.208, P = 0.2670).

CONCLUSIONS

Oocyte survival, fertilization rate, pregnancy and live birth rates are not affected by the time spent by vitrified oocytes in vapour-phase nitrogen tanks.

Oocyte and embryo cryopreservation in assisted reproductive technology: past achievements and current challenges

Cryopreservation has revolutionized the treatment of infertility and fertility preservation. This review summarizes the milestones that paved the way to the current routinary clinical implementation of this game-changing practice in assisted reproductive technology. Still, evidence to support "the best practice" in cryopreservation is controversial and several protocol adaptations exist that were described and compared here, such as cumulus-intact vs. cumulus-free oocyte cryopreservation, artificial collapse, assisted hatching, closed vs. open carriers, and others. A last matter of concern is whether cryostorage duration may impact oocyte/embryo competence, but the current body of evidence in this regard is reassuring. From social and clinical perspectives, oocyte and embryo cryopreservation has evolved from an afterthought when assisted reproduction was intended for immediate pregnancy with supernumerary embryos of secondary interest to its current purpose, which primarily is to preserve fertility long-term and more comprehensively allow for family planning. However, the initial consenting process, which still is geared to short-term fertility care, may no longer be relevant when the individuals that initially preserved the tissues have completed their reproductive journey. A more encompassing counseling model is required to address changing patient values over time.

[Indication and implementation of fertility preservation measures in female cancer patients]

The aspects of fertility preservation in women prior to surgical, gonadotoxic or radiation therapy represent a challenging topic in many disciplines and often in an interdisciplinary setting. Within an often short period of time, individual counselling and consideration must be given as to whether fertility-protective measures are useful. The implementation is ultimately decided by the patient. A prerequisite for helpful counselling is knowledge about the potential effects of cancer treatment on ovarian function as well as the implementation and potential individual benefits of fertility-protective measures. Networks such as FertiPROTEKT Netzwerk e. V. are helpful for orientation in terms of content and timely implementation of counselling and corresponding measures.

Fertility preservation in pediatric healthcare: a review

Survival rates for children and adolescents diagnosed with malignancy have been steadily increasing due to advances in oncology treatments. These treatments can have a toxic effect on the gonads. Currently, oocyte and sperm cryopreservation are recognized as well-established and successful strategies for fertility preservation for pubertal patients, while the use of gonadotropin-releasing hormone agonists for ovarian protection is controversial. For prepubertal girls, ovarian tissue cryopreservation is the sole option. However, the endocrinological and reproductive outcomes after ovarian tissue transplantation are highly heterogeneous. On the other hand, immature testicular tissue cryopreservation remains the only alternative for prepubertal boys, yet it is still experimental. Although there are several published guidelines for navigating fertility preservation for pediatric and adolescent patients as well as transgender populations, it is still restricted in clinical practice. This review aims to discuss the indications and clinical outcomes of fertility preservation. We also discuss the probably effective and efficient workflow to facilitate fertility preservation.

The live birth rate of vitrified oocyte accumulation for managing diminished ovarian reserve: a retrospective cohort study

BACKGROUND

Vitrified M-II oocyte accumulation for later simultaneous insemination has been used for managing POR. Our study aimed to determine whether vitrified oocyte accumulation strategy improves live birth rate (LBR) for managing diminished ovarian reserve (DOR).

METHODS

A retrospective study included 440 women with DOR fulfilling Poseidon classification groups 3 and 4, defined as the presence of serum anti-Müllerian hormone (AMH) hormone level < 1.2 ng/ml or antral follicle count (AFC) < 5, from January 1, 2014, to December 31, 2019, in a single department. Patients underwent accumulation of vitrified oocytes (DOR-Accu) and embryo transfer (ET) or controlled ovarian stimulation (COS) using fresh oocytes (DOR-fresh) and ET. Primary outcomes were LBR per ET and cumulative LBR (CLBR) per intention to treat (ITT). Secondary outcomes were clinical pregnancy rate (CPR) and miscarriage rate (MR).

RESULTS

Two hundred eleven patients underwent simultaneous insemination of vitrified oocyte accumulation and ET in the DOR-Accu group (maternal age: 39.29 ± 4.23 y, AMH: 0.54 ± 0.35 ng/ml), and 229 patients underwent COS and ET in the DOR-fresh group (maternal age: 38.07 ± 3.77 y, AMH: 0.72 ± 0.32 ng/ml). CPR in the DOR-Accu group was similar in the DOR-fresh group (27.5% vs. 31.0%, p = 0.418). However, MR was statistically higher (41.4% vs. 14.1%, p = 0.001), while LBR per ET was statistically lower (15.2% vs. 26.2%, p < 0.001) in the DOR-Accu group. There is no difference in CLBR per ITT between groups (20.4% vs. 27.5%, p = 0.081). The secondary analysis categorized clinical outcomes into four groups regarding patients' age. CPR, LBR per ET, and CLBR did not improve in the DOR-Accu group. In the group of 31 patients, accumulated vitrified metaphase II (M-II) oocytes reached a total number of ≥ 15, and CPR improved among the DOR-Accu group (48.4% vs. 31.0%, p = 0.054); however, higher MR (40.0% vs. 14.1%, p = 0.03) resulted in similar LBR per ET (29.0% vs. 26.2%, p = 0.738).

CONCLUSIONS

Vitrified oocyte accumulation for managing DOR did not improve LBR. Higher MR resulted in lower LBR in the DOR-Accu group. Therefore, the vitrified oocyte accumulation strategy for managing DOR is not clinically practical.

TRIAL REGISTRATION

The study protocol was retrospectively registered and was approved by Institutional Review Board of Mackay Memorial Hospital (21MMHIS219e) on August 26, 2021.

[The impact of oocyte cryopreservation time in oocyte donation on the clinical success rate]

OBJECTIVES

To evaluate the impact of the cryopreservation time of vitrified oocytes on the success rates in oocyte donation cycles.

METHODS

A retrospective study was carried out on 156 cycles with donated oocytes from January 2012 to September 2021. All the cycles were sorted according to the storage time of the oocytes (25 in the group 1:<3 months, 32 in the group 2: between 3 and 6 months, 39 in the group 3: between 6 and 12 months, 38 in the group 4: between 12 and 24 months and 22 in the group 5:>24 months). Clinical outcomes after ART, survival rates at thawing and oocyte fertilization rates were compared between the different cohorts stratified according to oocyte storage duration. A binary multivariate logistic regression was performed adjusting for the identified confounders.

RESULTS

Prolonged storage time of vitrified oocytes had an effect on their survival post-thawing rates, but no significant effect was identified on fertilization rates or clinical outcomes. After adjusting for the confounders, the relationships between clinical outcomes and oocytes storage time did not reach statistical significance. Our study was characterized by a limited cohort with data from a single ART center.

CONCLUSIONS

Our study doesn't highlight any significant difference in the use of long-stored vitrified oocytes (more than 2 years) on clinical issues in ART. The conclusion of our study needs to be verified in further studies with larger cohorts.

The use of oocyte cryopreservation for fertility preservation in patients with sex chromosome disorders: a case series describing outcomes

PURPOSE

Characterize outcomes among adolescents and young adults (AYAs) with sex chromosome disorders (SCDs) after oocyte cryopreservation (OC) consultation.

METHODS

Retrospective case series of all AYA (< 25 years) patients with SCDs seen for OC consultation from 2011 to 2019 at a large, urban, academic fertility center. All AYA patients with an SCD seen for OC consult in the study time period were reviewed and included. Data collected included patient age, SCD type, number of patients who attempted OC, number of cycles attempted, and cycle outcomes.

RESULTS

Twenty-two patients were included: 9 with Turner syndrome, 12 with mosaic Turner syndrome, and 1 with 47,XXX. Mean age at consult was 14.7 ± 3.5 years. Fourteen patients elected for OC: 5 with Turner syndrome, 8 with mosaic Turner syndrome, and 1 47,XXX who pursued 31 OC cycles total. Of those 14 patients, 10 underwent retrieval, 9 froze oocytes, and 8 froze mature (MII) oocytes. Seven patients underwent > 1 cycle and 7 had ≥ 1 cancelation. 3/3 patients who pursued cycles after 1st cancelation never got to retrieval. Age, SCD type, and baseline FSH did not predict ability to freeze MIIs. One patient returned after OC and attempted 4 ovulation induction cycles and 2 IVF cycles; all were canceled for low response.

CONCLUSIONS

AYA patients with SCDs have a high risk of poor response and cycle cancelation but the majority froze MIIs. Thus, setting expectations is important. A larger sample size is needed to evaluate possible clinical predictors of success.

The effects of vitrification on oocyte quality

Vitrification, is an ultra-rapid, manual cooling process that produces glass-like (ice crystal free) solidification. Water is prevented from forming intercellular and intracellular ice crystals during cooling as a result of oocyte dehydration and the use of highly concentrated cryoprotectant. Though oocytes can be cryopreserved without ice crystal formation through vitrification, it is still not clear whether the process of vitrification causes any negative impact (temperature change/chilling effect, osmotic stress, cryoprotectant toxicity, and/or phase transitions) on oocyte quality that translate to diminished embryo developmental potential or subsequent clinical outcomes. In this review, we attempt to assess the technique's potential effects and the consequence of these effects on outcomes.

Oocyte donation: not all oocyte cryobanks are the same

RESEARCH QUESTION

Is the efficacy of imported vitrified oocyte donation affected by the cryobank of origin?

DESIGN

Longitudinal cohort study, including 249 completed oocyte warming cycles from 200 recipients (January 2016-July 2020). No severe male factor was included. Vitrified oocytes were provided by three Spanish cryobanks. Primary outcome was cumulative live birth delivery rate (CLBR) per completed oocyte warming cycle.

RESULTS

After warming 1535 oocytes, 1244 survived (81.0%) and 945 fertilized (76.0%); embryo utilization rate was 65.3%. The overall CLBR per completed cycle was 47.0% but was lower in cryobank 1 (31.2%) versus cryobank 2 (56.0%, P = 0.0010) and cryobank 3 (50.8%, P = 0.0241). Multivariate logistic regression analysis identified survival of four or more oocytes as the strongest predictor for delivery (P = 0.0282). Only 202 out of 249 oocyte warming cycles had four or more survived oocytes in a proportion that was significantly lower in cryobank 1 versus cryobank 2 (70.1% versus 89.0%, P = 0.0020); comparison with cryobank 3 (81.0%) was not significant. In the 202 oocyte warming cycles, CLBR in cryobank 1 (37.0%) was lower versus cryobank 2 (58.8%, P = 0.0115) and cryobank 3 (60.8%, P = 0.0019), suggesting a reduced viability in oocytes from cryobank 1 that survived warming.

CONCLUSIONS

Differences were found in the efficacy of imported vitrified oocytes in relation to the cryobank of origin. Each centre needs to evaluate the results internally when starting a collaboration with an oocyte cryobank to establish the necessary measures to maximize treatment efficacy.

Oocyte Cryopreservation at a Young Age Provides an Effective Strategy for Expanding Fertile Lifespan

With an upward trend in delaying parenthood, women across the world face an increasing risk of age-related infertility and involuntary childlessness. Elective oocyte banking strategies offer women the possibility to protect part of their reproductive potential until personal finances, personal relationship, or career have stabilized. Timely collection and cryopreservation of oocytes when they are most competent and chromosomal abnormality rates have not yet escalated are crucial for achieving high live births through in vitro fertilization (IVF) treatment at a later stage. To promote reproductive autonomy, women shall be informed about the decrease in fertility rates that sharply intensifies from the age of 35 years and the strategies available to maintain their reproductive potential. Together with this information, women should also recognize the limitations of available strategies including expected live birth rates, costs of the procedures, and overall approach performance, which is mainly associated with age at cryopreservation, number of oocytes banked, and age at accessing the banked oocytes. Evidence-based statistics are not yet available due to the relatively short period in which oocyte cryopreservation has been offered for elective purposes and the scarce number of patients returning for accessing their oocytes. However, to evaluate the applicability of fertility cryopreservation on a large scale, several theoretical models have been proposed to assess the expected efficacy and overall cost-effectiveness of different oocyte banking strategies. In this study, we review current oocyte cryopreservation methodologies, their applications, and outcomes. Moreover, we summarize current evidence regarding known parameters affecting oocyte banking efficacy. Finally, we discuss key points that could play a role in improving access to the service and optimization of oocyte banking frameworks.

Ethical issues in oocyte banking for nonautologous use: an Ethics Committee opinion

Ethical considerations for the banking of oocytes for nonautologous use are discussed.

Factors predicting clinical outcomes from 494 vitrified oocyte donation cycles at a UK-regulated egg bank

RESEARCH QUESTION

Do donor age, AMH, AFC, BMI and reproductive history predict response to ovarian stimulation? Do donor and recipient clinical markers and embryology parameters predict recipient pregnancy and live birth?

DESIGN

Retrospective cohort study of 494 altruistic oocyte donors aged 18-35 years; 340 were matched to 559 recipients. Predictors of donor total oocyte yield and total mature oocyte yield were identified. Total and mature oocyte number were compared according to stratified donor AMH and age. Donor, recipient and embryology parameters predictive of recipient primary outcomes (clinical pregnancy and live birth) were identified.

RESULTS

Donor age and AMH predicted total oocyte yield (P = 0.030 and P < 0.001)) and total mature oocyte yield (P = 0.011 and P < 0.001). Donors aged 30-35 years with AMH 15-29.9 pmol/l had lower total oocyte yield (P = 0.004) and mature oocyte yield (P < 0.001) than donors aged 18-24 years. Up to an AMH threshold of 39.9 pmol/l, increasing AMH levels predicted higher total oocyte yield (<15 pmol/l versus 15-29.9 pmol/l, P = 0.001; 15-29.9 pmol/l versus 30-39.9 pmol/l, P < 0.001; 30-39.9pmol/l versus ≥ 40 pmol/l, P = 1.0) and mature oocyte yield (<15 pmol/l versus 15-29.9 pmol/l, P = 0.005; 15-29.9 pmol/l versus 30-39.9 pmol/l, P = 0.006; 30-39.9 pmol/l versus ≥40 pmol/l, P = 1.0). In recipients, the rate of transferrable embryos per oocytes received, fertilized and number of embryo transfers needed to achieve the primary outcome were predictors of cumulative clinical pregnancy (P = 0.011, P = 0.017 and P < 0.001) and live birth (P = 0.008, P = 0.012 and P < 0.001) rates. Recipient BMI (P = 0.024) and previous miscarriages (P = 0.045) were predictors of cumulative live birth rate. Donor age 18-22 years was associated with a lower incidence of recipient clinical pregnancy (P = 0.004) and live birth (P = 0.001) after the first embryo transfer versus donor age 23-29 years.

CONCLUSIONS

Donor age and AMH are independent predictors of oocyte yield. Raised recipient BMI and history of miscarriages reduce cumulative live birth rates, which may be increased by selecting donors aged 23-29 years, instead of younger donors.

Low progesterone levels on the day before natural cycle frozen embryo transfer are negatively associated with live birth rates

STUDY QUESTION

Are progesterone (P) levels on the day before natural cycle frozen embryo transfer (NC-FET) associated with live birth rate (LBR)?

SUMMARY ANSWER

Regular ovulatory women undergoing NC-FET with serum P levels <10 ng/ml on the day before blastocyst transfer have a significantly lower LBR than those with serum P levels >10 ng/ml.

WHAT IS KNOWN ALREADY

The importance of serum P levels around the time of embryo transfer in patients undergoing FET under artificial endometrial preparation has been well established. However, no study has analyzed the importance of serum P levels in patients undergoing FET under a true natural endometrial preparation cycle.

STUDY DESIGN, SIZE, DURATION

This was a retrospective cohort study including 294 frozen blastocyst transfers under natural cycle endometrial preparation at a university-affiliated fertility centre between January 2016 and January 2019.

PARTICIPANTS/MATERIALS, SETTING, METHODS

All patients had regular menstrual cycles and underwent NC-FET with their own oocytes. Only patients who had undergone serum P measurement between 8 am and 11 am on the day before FET were included. Patients did not receive any external medication for endometrial preparation or luteal phase support. Patients were divided into two groups according to serum P levels below or above 10 ng/ml on the day before FET. Univariate analysis was carried out to describe and compare the cycle characteristics with reproductive outcomes. To evaluate the effect of P, a multivariable logistic model was fitted for each outcome after adjusting for confounding variables.

MAIN RESULTS AND THE ROLE OF CHANCE

Mean serum P levels on the day before FET were significantly higher in patients who had a live birth compared to those who did not (14.5 ± 7.0 vs 12.0 ± 6.6 ng/ml, 95% CI [0.83; 4.12]). The overall clinical pregnancy rate (CPR) and LBR were 42.9% and 35.4%, respectively. Patients in the higher P group (>10 ng/ml) had a higher LBR (41.1% vs 25.7%: risk difference (RD) 15.4%, 95% CI [5; 26]) and CPR (48.6% vs 33.0%: RD 15.6%, 95% CI [4; 27]). Patients with higher serum P levels on the day before FET (63% of patients) had an improved LBR (odds ratio: 1.05; 95% CI [1.02; 1.09]). Women with serum P levels <10 ng/ml on the day before FET (37% of patients) had significantly higher weights (62.5 ± 9.9 vs 58.1 ± 7.1 kg, 95% CI [1.92; 6.90]) and BMI (22.9 ± 3.6 vs 21.6 ± 2.7 kg/m2, 95% CI [0.42; 2.25]) compared to patients with P levels >10 ng/ml.

LIMITATIONS, REASONS FOR CAUTION

The main limitation of our study is its retrospective design. Other potential limitations are the detection of LH surge through urine testing and the inclusion of patients who did and did not undergo preimplantation genetic testing for aneuploidies. The protocol used in our institution for monitoring NC-FET does not look for the onset of progesterone secretion by the corpus luteum, and a slow luteinisation process or delay of corpus luteum function cannot be ruled out.

WIDER IMPLICATIONS OF THE FINDINGS

We provide evidence that a minimum serum P threshold (P >10 ng/ml) might be required for improved reproductive outcomes in NC-FET. This result suggests that there are different mechanisms by which P is produced and/or distributed by each patient. This study also provides an excellent model to evaluate the impact of luteal phase defect through NC-FET. A prospective evaluation to assess whether P supplementation should be individualised according to patient's needs is necessary to support our findings.

STUDY FUNDING/COMPETING INTEREST(S)

No external funding was used, and there are no competing interests.

Systematic review of fertility preservation options in transgender patients: a guide for plastic surgeons

Transgender patients often desire to have biological children. However, their reproductive potential is often negatively impacted by gender affirming surgery (GAS) such as gender confirmation surgery (bottom surgery) and medical hormone therapy. Therefore, counselling patients on fertility preservation options before initiating gender-affirming treatments is prudent to avoid reducing their reproductive potential. A systematic review of English, Spanish, Chinese, French and Turkish languages from 2000 to December 23rd, 2019, using the preferred reporting items for systematic review and meta-analysis protocols (PRISMA-P) guidelines, was conducted. The search strategy was designed and conducted by an experienced librarian with input from the study's principle investigator. Fifteen articles that report outcomes of fertility preservation options in transgenders were included. Eight articles described options for transgender women, six reported options for transgender men and one included both transgender women and transgender men. Semen cryopreservation and oocyte cryopreservation are the most common and available methods for fertility preservation in transgenders. Physician awareness of fertility preservation options in transgender patients is crucial to ensure informed discussions regarding reproductive options in the early phase of transition.

Ovarian stimulation for oocyte donation: a systematic review and meta-analysis

BACKGROUND

Since its introduction in the 1980s, oocyte donation (OD) has been largely integrated into ART. Lately, both demand and the indications for OD have increased greatly. Oocyte donors are healthy and potentially fertile women undergoing voluntarily ovarian stimulation (OS). Selection of the optimal type of stimulation is of paramount importance in order to achieve the most favourable outcomes for the oocyte recipients, but most importantly for the safety of the oocyte donors.

OBJECTIVE AND RATIONALE

This is the first systematic review (SR) with the objective to summarize the current evidence on OS in oocyte donors. The scope of this SR was to evaluate the OD programme by assessing four different aspects: how to assess the ovarian response prior to stimulation; how to plan the OS (gonadotrophins; LH suppression; ovulation trigger; when to start OS); how to control for the risk of ovarian hyperstimulation syndrome (OHSS) and other complications; and the differences between the use of fresh versus vitrified donated oocytes.

SEARCH METHODS

A systematic literature search was conducted in May 2020, according to PRISMA guidelines in the databases PubMed and Embase, using a string that combined synonyms for oocytes, donation, banking, freezing, complications and reproductive outcomes. Studies reporting on the safety and/or efficacy of OS in oocyte donors were identified. The quality of the included studies was assessed using ROBINS-I and ROB2. Meta-analysis was performed where appropriate. Data were combined to calculate mean differences (MD) for continuous variables and odd ratios (OR) for binary data with their corresponding 95% CIs. Heterogeneity between the included studies was assessed using I2 and tau statistics.

OUTCOMES

In total, 57 manuscripts were selected for the review, out of 191 citations identified. Antral follicle count and anti-Müllerian hormone levels correlate with ovarian response to OS in OD but have limited value to discriminate donors who are likely to show either impaired or excessive response. Five randomized controlled trials compared different type of gonadotrophins as part of OS in oocyte donors; owing to high heterogeneity, meta-analysis was precluded. When comparing different types of LH control, namely GnRH antagonist versus agonist, the studies showed no differences in ovarian response. Use of progesterone primed ovarian stimulation protocols has been evaluated in seven studies: the evidence has shown little or no difference, compared to GnRH antagonist protocols, in mean number of retrieved oocytes (MD 0.23, [95% CI 0.58-1.05], n = 2147; 6 studies; I2 = 13%, P = 0.33) and in clinical pregnancy rates among recipients (OR 0.87 [95% CI 0.60-1.26], n = 2260, I2 = 72%, P < 0.01). There is insufficient evidence on long-term safety for babies born. GnRH agonist triggering is the gold standard and should be used in all oocyte donors, given the excellent oocyte retrieval rates, the practical elimination of OHSS and no differences in pregnancy rates in recipients (four studies, OR 0.86, 95%CI 0.58-1.26; I2 = 0%). OS in OD is a safe procedure with a low rate of hospitalization after oocyte retrieval. The use of a levonorgestrel intrauterine device or a progestin contraceptive pill during OS does not impact the number of oocytes retrieved or the clinical pregnancy rate in recipients. Ultrasound monitoring seems enough for an adequate follow up of the stimulation cycle in OD. Use of fresh versus vitrified donated oocytes yielded similar pregnancy outcomes.

WIDER IMPLICATIONS

This update will be helpful in the clinical management of OS in OD based on the most recent knowledge and recommendations, and possibly in the management of women under 35 years undergoing oocyte vitrification for social freezing, owing to the population similarities. More clinical research is needed on OS protocols that are specifically designed for OD, especially in term of the long-term safety for newborns, effective contraception during OS, and treatment satisfaction.

Fresh oocyte cycles yield improved embryo quality compared with frozen oocyte cycles in an egg-sharing donation programme

The objective of this study was to investigate any effect of cryopreservation of donated eggs on laboratorial and clinical outcomes of intracytoplasmic sperm injection (ICSI) cycles. This retrospective cohort study included 320 oocyte recipients undergoing 307 vitrified and 119 fresh oocyte recipient ICSI cycles, participating in an egg-sharing donation programme, from 2015 to 2018, in a private university-affiliated in vitro fertilization (IVF) centre. A review of donor and recipient ICSI cycles was charted. A general mixed models fit by restricted maximum likelihood, followed by Bonferroni post hoc test was used to compare the means between fresh and warm oocyte donation groups and investigate the effect of cryopreservation on recipient ICSI outcome. The main outcome measure was blastocyst development rates. Fertilization rate, high-quality embryo rates on days 2 and 3, normal cleavage speed rates on days 2 and 3, and blastocyst development rate were significantly higher for the fresh oocyte donation cycles compared with warmed oocyte donation cycles. In the egg-sharing donation programme, fertilization and embryo developmental competence were reduced when vitrified oocytes from infertile couples were used for ICSI compared with fresh oocytes.

Oocyte cryopreservation - current scenario and future perspectives: A narrative review

Oocyte cryopreservation is a boon for women undergoing assisted reproductive technology. With the evolution in the technique of cryopreservation over the last three decades, there has been an exponential rise in the number of oocyte cryopreservation cycles for diverse indications. Apart from cancer patients, it has also been promoted as a mode of fertility insurance to overcome the age-related decline in fertility as well as post-surgical decline following endometriosis surgery. The objective of the review is to evaluate its clinical applications, ideal age at freezing, optimal oocyte number, freezing method of choice, efficacy, safety and recent advances. In the last decade, vitrification has surpassed slow freezing for oocyte cryopreservation. Although closed system of vitrification provides the aseptic environment, open vitrification is commonly followed in practice. Early to mid-thirties is a reasonable age group for planned oocyte cryopreservation, although it might be recommended at a younger age, in patients with diminished ovarian reserve. The patients should be motivated to preserve around 14–20 mature oocytes for successful live birth. Various studies have shown comparable fertilisation and pregnancy rates between Intracytoplasmic sperm injection with fresh and frozen-thawed oocytes. The available evidence has shown no increase in the incidence of congenital abnormalities in babies born through vitrified oocytes. In the future, image analysis using artificial intelligence, and spindle visualisation using poloscope may further enhance the outcome of oocyte cryopreservation.

COH outcomes in breast cancer patients for fertility preservation: a comparison with the expected response by age

PURPOSE

Breast cancer is the most common cancer diagnosed during childbearing age, and fertility preservation is becoming increasingly more essential. However, recent studies indicate a possible poorer response to controlled ovarian hyperstimulation (COH) in cancer patients than in non-cancer controls and a negative impact of BRCA mutations on female fertility. This study aims to evaluate ovarian response and the number of mature oocytes (MII) vitrified in women with breast cancer, with or without BRCA mutation, comparing them to the expected response according to an age-related nomogram.

METHODS

This is a retrospective observational study involving sixty-one breast cancer patients who underwent COH for oocyte cryopreservation. The age-specific nomogram was built using 3871 patients who underwent COH due to oocyte donation, fertility preservation for non-medical reasons, or FIVET for male factor exclusively.

RESULTS

The mean number of oocytes retrieved was 13.03, whereas the mean number of MII oocytes was 10.00. After the application of the z-score, no statistically significant differences were found compared with the expected response in the general population, neither by dividing patients according to the presence or absence of BRCA mutation nor according to the phase in which they initiated stimulation.

CONCLUSION

The results obtained do not support the notion of a negative impact of the BRCA mutation on the ovarian response of women with breast cancer. Women with breast cancer undergoing COH for fertility preservation can expect the ovarian response predicted for their age.

What impact does oocyte vitrification have on epigenetics and gene expression?

Children conceived by assisted reproductive technologies (ART) have a moderate risk for a number of adverse events and conditions. The question whether this additional risk is associated with specific procedures used in ART or whether it is related to the intrinsic biological factors associated with infertility remains unresolved. One of the main hypotheses is that laboratory procedures could have an effect on the epigenome of gametes and embryos. This suspicion is linked to the fact that ART procedures occur precisely during the period when there are major changes in the organization of the epigenome. Oocyte freezing protocols are generally considered safe; however, some evidence suggests that vitrification may be associated with modifications of the epigenetic marks. In this manuscript, after describing the main changes that occur during epigenetic reprogramming, we will provide current information regarding the impact of oocyte vitrification on epigenetic regulation and the consequences on gene expression, both in animals and humans. Overall, the literature suggests that epigenetic and transcriptomic profiles are sensitive to the stress induced by oocyte vitrification, and it also underlines the need to improve our knowledge in this field.

Comparison of two different oocyte vitrification methods: a prospective, paired study on the same genetic background and stimulation protocol

STUDY QUESTION

Can two different methods for oocyte vitrification, one using an open tool and the other a closed tool, result in similar oocyte survival rates?

SUMMARY ANSWER

The oocyte survival rate was found to be higher in the closed method.

WHAT IS KNOWN ALREADY

Open vitrification is performed routinely in oocyte donation cycles. Closed oocyte vitrification may result in slower cooling rates and thus it is less used, even though it has been recommended in order to avoid the risk of cross-contamination between material from different patients.

STUDY DESIGN, SIZE, DURATION

This is a prospective cohort study with sibling oocytes carried out in a fertility center between July 2014 and January 2016. The study included 83 oocyte donors each providing a minimum of 12 mature oocytes (metaphase II: MII) at oocyte retrieval. Oocyte survival rate and fertilization rate, as well as reproductive outcomes (biochemical, clinical, ongoing pregnancy and live birth rates) per embryo transfer and also cumulatively between the two methods were compared by Chi2 tests.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Donor oocytes were denuded and six MII oocytes from each donor were vitrified using an open method and later assigned to one recipient, while another six MII oocytes were vitrified using a closed method and assigned to a different recipient (paired analysis). ICSI was used in all cases and embryo transfer was performed on Day 2-3 in all cases.

MAIN RESULTS AND THE ROLE OF CHANCE

Oocyte donors were 24.8 years old on average (SD 4.7). Recipient age (average 41.2 years, SD 4.7) and BMI (mean 23.8 kg/m2, SD 4.0) were similar between recipient groups. Oocytes vitrified using the closed method had higher survival rate (94.5% versus 88.9%, P = 0.002), but lower fertilization rate (57.1% versus 69.8%, P < 0.001) compared to the open method. The number of fresh embryos transferred in the two groups was 1.8 on average (SD 0.4). Biochemical (45% closed versus 50% open), clinical (40% versus 50%) and ongoing (37.5% versus 42.5%) pregnancy rates were not different between groups (P > 0.05) and neither were live birth rates (37.5% versus 42.5%, P > 0.05). Cumulative reproductive results (obtained after the transfer of all the embryos) were also similar between groups.

LIMITATIONS, REASONS FOR CAUTION

The participants of this study were oocyte donors, i.e. young women in good health, and care should be exerted in extending our results to other populations such as infertility patients, oncofertility patients and women freezing oocytes to delay childbearing.

WIDER IMPLICATIONS OF THE FINDINGS

Our results suggest that, in spite of different survival and fertilization rates, closed and open oocyte vitrification methods should offer similar reproductive outcomes up to cumulative live birth rates.

STUDY FUNDING/COMPETING INTEREST(S)

The authors report no conflict of interest. Vitrolife provided the media and the closed method tool needed for the study at no cost.

Single or double embryo transfer? Decision-making process in patients participating in an oocyte donation program

In IVF/ICSI programs, after receiving the information about the success results of single embryo transfer (SET) vs double embryo transfer (DET) and the risks of multiple pregnancy, a significant number of patients opt for SET. Up to date, no comparable studies have been published in oocyte recipients. The aim of this study was to evaluate if the counseling provided to oocyte recipients influence their decision on the number of embryos to be transferred. Fifty-five recipients expressed their preference and the relevance for the decision-making process that they attribute to certain factors through an anonymous questionnaire completed pre and post-counseling. Before counseling, 32 out of 55 recipients preferred DET, 13 preferred SET and 10 were undecided. From the 32 recipients who preferred DET, 16 (50%) maintained their preference after counseling, 13 (40.6%) changed their decision to SET and 3 (9.4%) changed to undecided (McNemar's test: p < .05). After counseling, the patients attached less importance to the probability of pregnancy and more importance to maternal and perinatal risks (p < .05). We conclude that after counseling, a significant number of recipients changed their preferences from DET to SET.

COMPARATIVE ANALYSIS OF PROGRAMS WITH THE USE OF NATIVE AND CRYOPRESERVED OOCYTES IN IN -VIRTO FERTILIZATION PROCEDURES

This article release data about comparative survival of oocytes after freezing, fertilization, blastocyst formation and clinical results of IVF/ICSI programs in International Clinical Centre of Reproductology Persona during period from 2016 to 2019.

Factors associated with serum progesterone concentrations the day before cryopreserved embryo transfer in artificial cycles

RESEARCH QUESTION

What factors determine serum progesterone concentrations the day before cryopreserved embryo transfer in artificially prepared cycles?

DESIGN

Retrospective cohort study at a university-affiliated fertility centre including infertile women under 45 years old using own oocytes who underwent a total of 685 single cryopreserved blastocyst transfers under hormonal therapy. Determinants that affected live birth rate (LBR) were analysed using a multivariate logistic regression. Univariate analysis and multivariate linear regression were used to evaluate independent factors that affect serum progesterone concentrations.

RESULTS

Age (odds ratio [OR] 0.93; 95% confidence interval [CI] 0.89-0.96), duration of oestradiol (OR 0.96; 95% CI 0.92-0.99), serum progesterone concentrations (OR 1.04; 95% CI 1.01-1.08) and patients who underwent preimplantation genetic testing for aneuploidies (PGT-A) (OR 2.17; 95% CI 1.55-3.03) were independently associated with LBR. After univariate analysis, determinants of progesterone concentrations were: age, weight, history of a previous cryopreserved embryo transfer with serum progesterone concentrations <10 ng/ml, and time of blood extraction. The multivariate linear regression showed that increasing age presented a positive correlation with progesterone concentrations (β = 0.11; 95% CI 0.01-0.20). On the contrary, significant negative correlations with progesterone concentrations were shown for a previous history of serum progesterone value <10 ng/ml (β = -3.13; 95% CI -4.45 to -1.81]), higher weight (β = -0.05; 95% CI -0.08 to -0.01) and the time of blood sampling during the day (β = -0.13; 95% CI -0.25 to -0.01).

CONCLUSIONS

This study adds more evidence regarding the importance of serum progesterone concentrations before frozen embryo transfer (FET). It also showed that body weight, age, time of blood sampling and a history of low progesterone are determinants associated with progesterone concentrations before blastocyst FET.

Progress in Fertility Preservation Strategies in Turner Syndrome

Growth retardation and gonadal dysgenesis are two of the most important clinical manifestations of Turner syndrome (TS). As premature ovarian failure generally occurs early in life in women with TS, these patients should be counseled and evaluated as early as possible for discussion of optimal and individualized fertility preservation strategies. Infertility seriously affects the quality of life of women with TS. For those who have ovarian reserve, the theoretical options for future fertility in TS patients include cryopreservation of oocytes, ovarian tissues, and embryos. For those who have already lost their ovarian reserve, oocyte or embryo donation, gestational surrogacy, and adoption are strategies that allow fulfillment of desire for parenting. This review describes the etiologies of infertility and reviews the fertility preservation strategies for women with TS.

Human oocytes and zygotes are ready for ultra-fast vitrification after 2 minutes of exposure to standard CPA solutions

Vitrification of human oocytes and embryos in different stages of development is a key element of daily clinical practice of in vitro fertilization treatments. Despite the cooling and warming of the cells is ultra-fast, the procedure as a whole is time consuming. Most of the duration is employed in a long (8–15 minutes), gradual or direct exposure to a non-vitrifying cryoprotectant solution, which is followed by a short exposure to a more concentrated vitrifying solution. A reduction in the duration of the protocols is desirable to improve the workflow in the IVF setting and reduce the time of exposure to suboptimal temperature and osmolarity, as well as potentially toxic cryoprotectants. In this work it is shown that this reduction is feasible. In silico (MatLab program using two-parameter permeability model) and in vitro observations of the oocytes’ osmotic behaviour indicate that the dehydration upon exposure to standard cryoprotectant solutions occurs very fast: the point of minimum volume of the shrink-swell curve is reached within 60 seconds. At that point, intracellular water ejection is complete, which coupled with the permeation of low molecular weight cryoprotectants results in similar intracellular and extracellular solute concentrations. This shows that prolonging the exposure to the cryoprotectant solutions does not improve the cytosolic glass forming tendency and could be avoided. To test this finding, human oocytes and zygotes that were donated for research were subjected to a shortened, dehydration-based protocol, consisting of two consecutive exposures of one-minute to two standard cryoprotectant solutions, containing ethylene glycol, dimethyl sulfoxide and sucrose. At the end of this two-minute dehydration protocol, the critical intracellular solute concentration necessary for successful vitrification was attained, confirmed by the post-warming survival and ability to resume cytokinesis of the cells. Further studies of the developmental competency of oocytes and embryos would be necessary to determine the suitability of this specific dehydration protocol for clinical practice, but based on our results, short times of exposure to increasingly hypertonic solutions could be a more time-efficient strategy to prepare human oocytes and embryos for vitrification.

Desogestrel versus antagonist injections for LH suppression in oocyte donation cycles: a crossover study

To study whether ovarian response to corifollitropin among oocyte donors (OD) is different when oral desogestrel (DSG) is used to block the luteinizing hormone (LH) surge when compared to GnRH-antagonist use. This is a retrospective, cohort study at a private, university-based, IVF center including 35 OD. Patients underwent two stimulation cycles under corifollitropin alfa (CFT), one under an antagonist and another under DSG, between February 2015 and May 2017. In antagonist cycles, daily ganirelix was administered since a leading follicle reached 14 mm. In the DSG cycles, daily oral DSG was prescribed. The main outcome measure was oocytes retrieved. Compared to antagonist cycles, cycles under DSG received fewer injections (10.3 ± 2.8 vs. 5.0 ± 2.1, p < .001), nominally lower total supplementary gonadotropin dose (497.4 ± 338.9I U vs. 442.9 ± 332.8 IU, p=.45) with a lower total cost of medication (1018.6 ± 191.0€ vs. 813.8 ± 145.9€, p<.001). There were no differences in the total number of retrieved oocytes between groups (17.4 ± 7.5 vs. 18.6 ± 8.9, p=.34). In the corresponding oocyte recipients, clinical pregnancy rate was similar between groups: 52.0% vs. 58.6%, respectively (p=.78). ODs' stimulation's response under DSG is similar when compared to (17.4 ± 7.5 vs. 18.6 ± 8.9, p=.34) but associated with less injections and lower medication costs. The main advantage of this strategy is its simplicity, an aspect of utmost importance in the management of ODs.

Ovarian response in oocyte donation cycles under LH suppression with GnRH antagonist or desogestrel progestin: retrospective and comparative study

Here are investigated the serum hormones in ovarian stimulation cycles of oocyte donors (OD), under endogenous luteinizing hormone (LH) suppression with GnRH antagonist (antGnRH) vs. desogestrel (DSG) (progesterone-primed [PP]). OD underwent ovarian stimulation with gonadotropins at a private, university-based, infertility center between January 2017 and March 2018. Endogenous LH peak was controlled with either daily injections of antGnRH or with daily oral 75 mcg DSG (PP) until triggering. LH and progesterone were measured at trigger and the following day. A total of 404 OD cycles were included. There were no differences in age (26.7 ± 4.9 vs. 27.1 ± 4.8 years), AMH (3.7 ± 2.1 vs. 4.1 ± 2.7 ng/ml), and body mass index (BMI) (22.4 ± 2.8 vs. 22.1 ± 3.0 kg/m²) between PP and antGnRH groups, respectively. On the day of trigger, progesterone was lower in PP compared to antGnRH (0.9 ± 0.7, vs. 1.5 ± 1.2 ng/ml, p < .001), whereas no significant differences existed in estradiol or LH. On the day after trigger, lower progesterone in PP vs. antGnRH (10.8 ± 6.0 vs. 13.4 ± 7.9 ng/ml, p=.002) was observed. No differences were observed in the number of retrieved oocytes or the clinical pregnancies among recipients. Our study shows that endocrine response to DSG differs significantly as compared to antGnRH use for the control of endogenous LH without apparent impact on number of retrieved oocytes or the clinical pregnancies among recipients.

[Causes of oocyte vitrification and its value in assisted reproductive technology]

OBJECTIVE

To explore the causes of oocyte vitrification and its application in assisted reproduction.

METHODS

We retrospectively analyzed the data of 26 patients with 27 cycles of oocyte vitrification cryopreservation undergoing intracytoplasmic sperm injection (ICSI) and embryo transfer between January, 2008 and October, 2018. The causes of oocyte vitrification and the outcomes of ICSI and clinical pregnancy were analyzed.

RESULTS

The causes of oocytes vitrification included mainly azoospermia or severe spermatogenesis disorder of the husband, failure to obtain sperms from the husband, failure of the husband to be present on the day of oocyte retrieval and acute diseases of the husband to not allow sperm collection. A total of 274 oocytes were frozen in 27 oocyte retrieval cycles, and 217 eggs were thawed in 19 cycles with a survival rate of 81.11% (176/217). The normal fertilization rate, cleavage rate and high-quality embryo rate was 74.81% (98/131), 89.80% (88/98) and 36.73% (36/98), respectively. Fifteen patients underwent embryo transfer, and the clinical pregnancy rate and live birth rate was 53.33% (8/15) and 33.33% (5/15), respectively. Compared with patients below 35 years of age, the patients aged above 35 years had significantly lower oocyte survival rate after thawing (82.76% vs 74.42%, P=0.211), clinical pregnancy rate (77.78% vs 16.67%, P=0.041) and live birth rate (55.56% vs 0, P=0.044).

CONCLUSIONS

Oocytes vitrification can be used as a remedy for infertile couples who fail to provide sperms due to male factors on the day of oocyte retrieval. Vitrification of the oocytes does not significantly affect the fertilization rate or the clinical pregnancy rate. The survival rate of the thawed oocytes is related to the age of the wife, and an age younger than 35 years can be optimal for achieving favorable clinical pregnancy outcomes after oocyte vitrification.

Oocyte Cryopreservation in Adolescent Women

STUDY OBJECTIVE

To describe oocyte cryopreservation (OC) cycles in adolescent women (<20 years of age) performed at Society for Assisted Reproductive Technology member clinics in the United States from 2012 to 2016.

DESIGN

Retrospective cohort study.

SETTING

Not applicable.

PARTICIPANTS

OC cycles from the Technology Clinic Outcome Reporting System database.

INTERVENTIONS

OC cycles from 2012 to 2016 among adolescent women were compared with cycles in older women.

MAIN OUTCOME MEASURE

Number of oocytes retrieved.

RESULTS

From 2012 to 2016, OC cycles in women younger than 20 years of age accounted for 1.5% of OC cycles in all women. The absolute number has increased over the 5-year period, parallel to the increase in older women. OC cycles in adolescent women were most likely performed for fertility preservation for impending gonadotoxic treatment. The women were most likely to be non-Hispanic white and reside in the Northeast. Ten percent of the cycles were cancelled, most commonly for low response, compared with 6.6% of cycles in other age groups. There was no difference in mean oocytes retrieved in women younger than 20 years (n = 18.0) compared with women 20-29 years (n = 18.4). Complications, including ovarian hyperstimulation syndrome, were very rare.

CONCLUSION

OC cycles in adolescent women are similar with regard to stimulation characteristics and oocyte yield to those in women of other age groups. There is, however, a higher likelihood of cancellation because of poor response.

Low serum progesterone the day prior to frozen embryo transfer of euploid embryos is associated with significant reduction in live birth rates

A retrospective cohort study was performed to examine whether, in artificial endometrial preparation for frozen embryo transfer (FET) cycles, progesterone (P) levels the day prior to embryo transfer of euploid embryos have an impact on pregnancy outcomes. In a private university clinic, 244 FETs between January 2016 and June 2017 were analyzed. Endometrial preparation was achieved with estradiol valerate and vaginal micronized progesterone. Serum P and estradiol levels the day prior to embryo transfer were measured. A multivariable analysis to assess the relationship between serum P level and pregnancy outcomes was performed, adjusted for confounding variables. Mean P value was 11.3 ± 5.1 ng/ml. Progesterone levels were split in quartiles: Q1: ≤ 8.06 ng/ml; Q2: 8.07-10.64 ng/ml; Q3: 10.65-13.13 ng/ml; Q4: > 13.13 ng/ml. Patients included in the lower P quartile had a significantly higher miscarriage rate and significantly lower live birth rate (LBR) compared to the higher ones. A low serum P level (≤ 10.64 ng/ml) one day before FET is associated with a lower pregnancy and LBR following FET of euploid embryos.

Inconclusive results in preimplantation genetic testing: go for a second biopsy?

The transition in biopsy timing from blastomere to trophectoderm biopsy has led to a remarkable decrease in the percentage of undiagnosed blastocysts. However, patients with few or no euploid blastocysts can be affected by this residual percentage of diagnosis failure. The aim of this study is to assess whether blastocyst rebiopsy and revitrification is an efficient and safe procedure to be applied in cases of no results after analysis. Fifty-three patients agreed to the warming of 61 blastocysts to perform a second biopsy and PGT-A by aCGH. Only 75.4% of the blastocysts survived, reexpanded, and could be rebiopsied. After the second biopsy and analysis, 95.6% of the blastocysts were successfully diagnosed with an euploidy rate of 65.9%. Eighteen euploid blastocysts were warmed and transferred to 18 patients with a 100% survival and reexpansion rate. Seven clinical pregnancies have been achieved with 4 live births, 1 ongoing pregnancy, and 2 miscarriages. Thus, although few transfers of rebiopsied and revitrified blastocysts have been performed till date, our preliminary results show that this approach is efficient and safe to be applied for undiagnosed blastocysts, as it ultimately allows the transfer of euploid blastocysts and good clinical outcomes.

Immature Oocyte for Fertility Preservation

In vitro maturation (IVM) of human immature oocytes has been offered to women who are at risk of developing ovarian hyperstimulation syndrome (OHSS) caused by gonadotropin stimulation, such as PCO(S) patients or who have poor ovarian reserve. Cryopreservation of oocytes matured in vivo obtained in IVF cycles has improved after implementing the vitrification method and many successful results have been reported. Now, this procedure can be successfully offered to fertility preservation programs for patients who are in danger of losing their ovarian function due to medical or social reasons, and to oocyte donation programs. This vitrification technique has also been applied to cryopreserve oocytes obtained from IVM program. Some advantages of oocytes vitrification related with IVM are: (1) eliminating costly drugs and frequent monitoring; (2) completing treatment within 2 to 10 days (3) avoiding the use of hormones in cancer patients with hormone-sensitive tumors; and (4) retrieving oocytes at any point in menstrual cycle, even in the luteal phase. In addition, immature oocytes can also be collected from extracorporeal ovarian biopsy specimens or ovaries during caesarian section. Theoretically, there are two possible approaches for preserving immature oocytes: oocyte cryopreservation at the mature stage (after IVM) and oocyte cryopreservation at the Germinal Vesicle (GV)-stage (before IVM). Both vitrification of immature oocyte before/after IVM is not currently satisfactory. Nevertheless, many IVF centers worldwide are doing IVM oocyte cryopreservation as one of the options to preserve fertility for female cancer. Therefore, more studies are urgently required to improve IVM- and vitrification method to successfully preserve oocytes collected from cancer patients. In this review, present oocyte maturation mechanisms and recent progress of human IVM cycles will be discussed first, followed by some studies of the vitrification of human IVM oocyte.

A Comparison of Pregnancy Outcomes in Patients Undergoing Donor Egg Single Embryo Transfers With and Without Preimplantation Genetic Testing

Two of the many milestone developments in the field of assisted reproduction have been oocyte donation and preimplantation genetic testing for aneuploidy (PGT-A). Because it has been demonstrated that even young women produce a meaningful proportion of aneuploid embryos, screening out such abnormalities could potentially increase the efficacy of donor egg (DE) cycles. In this retrospective cohort study, we investigated the effect of PGT-A on DE cycle outcomes, including implantation rate (IR), spontaneous abortion rate (SABR), and ongoing pregnancy/live birth rate. We used fresh and frozen donor cycles not using PGT-A as comparison groups; all cases involved single embryo transfer. Data analysis revealed that PGT-A did not improve pregnancy outcome metrics in DE cycles, although there was a trend toward decreasing the SABR. There was a significant increase in IR with fresh cycles outperforming all frozen cycles. Overall, these results suggest that the benefits of performing PGT-A on embryos derived from young DEs may be limited and that there is an effect of the freezing process on pregnancy outcomes. These findings may provide useful insights into the science and practice of PGT-A across all of its applications.

Update on fertility preservation from the Barcelona International Society for Fertility Preservation-ESHRE-ASRM 2015 expert meeting: indications, results and future perspectives

STUDY QUESTION

What progress has been made in fertility preservation (FP) over the last decade?

SUMMARY ANSWER

FP techniques have been widely adopted over the last decade and therefore the establishment of international registries on their short- and long-term outcomes is strongly recommended.

WHAT IS KNOWN ALREADY

FP is a fundamental issue for both males and females whose future fertility may be compromised. Reproductive capacity may be seriously affected by age, different medical conditions and also by treatments, especially those with gonadal toxicity. There is general consensus on the need to provide counselling about currently available FP options to all individuals wishing to preserve their fertility.

STUDY DESIGN, SIZE, DURATION

An international meeting with representatives from expert scientific societies involved in FP was held in Barcelona, Spain, in June 2015.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Twenty international FP experts belonging to the American Society of Reproductive Medicine, ESHRE and the International Society of Fertility Preservation reviewed the literature up to June 2015 to be discussed at the meeting, and approved the final manuscript. At the time this manuscript was being written, new evidence considered relevant for the debated topics was published, and was consequently included.

MAIN RESULTS AND THE ROLE OF CHANCE

Several oncological and non-oncological diseases may affect current or future fertility, either caused by the disease itself or the gonadotoxic treatment, and need an adequate FP approach. Women wishing to postpone maternity and transgender individuals before starting hormone therapy or undergoing surgery to remove/alter their reproductive organs should also be counselled accordingly. Embryo and oocyte cryopreservation are first-line FP methods in post-pubertal women. Metaphase II oocyte cryopreservation (vitrification) is the preferred option. Cumulative evidence of restoration of ovarian function and spontaneous pregnancies after ART following orthotopic transplantation of cryopreserved ovarian tissue supports its future consideration as an open clinical application. Semen cryopreservation is the only established method for FP in men. Testicular tissue cryopreservation should be recommended in pre-pubertal boys even though fertility restoration strategies by autotransplantation of cryopreserved testicular tissue have not yet been tested for safe clinical use in humans. The establishment of international registries on the short- and long-term outcomes of FP techniques is strongly recommended.

LIMITATIONS, REASONS FOR CAUTION

Given the lack of studies in large cohorts or with a randomized design, the level of evidence for most of the evidence reviewed was three or below.

WIDER IMPLICATIONS OF THE FINDINGS

Further high quality studies are needed to study the long-term outcomes of FP techniques.

STUDY FUNDING/COMPETING INTEREST(S)

None.

TRIAL REGISTRATION NUMBER

N/A.

Thirteen years' experience in fertility preservation for cancer patients after in vitro fertilization and in vitro maturation treatments

PURPOSE

This study aims to describe the experience and outcomes of in vitro maturation without ovarian stimulation (IVM-FP) and conventional in vitro fertilization after ovarian stimulation (IVF-FP) in a fertility preservation (FP) program for women with cancer.

METHODS

Retrospective cohort study from 2003 to 2015 was conducted. The study population consisted of 353 women with cancer who underwent 394 FP cycles (187 IVF-FP cycles and 207 IVM-FP) for oocytes and/or embryos cryopreservation.

RESULT(S)

Comparatively with IVM-FP, IVF-FP had a higher median [25th-75th percentile] number of oocytes collected-12 [8-18] vs 7 [5-13]; oocytes cryopreserved-10 [6-15] vs 5 [2-8]; and, where applicable, embryos cryopreserved-5 [3-7] vs 3 [2-5] (p < 0.000001). Following FP treatment, 32 patients (9.0%) died, 18 patients (5.6%) conceived spontaneously, and 23 patients (6.5%) returned to attempt pregnancy with a median lapse of returning of 4.6 [3.1-6.1] years. Of these, cryopreserved oocytes or embryos were used in 33 cycles (19 after IVF-FP and 14 after IVM-FP). Overall, the cumulative pregnancy rate (CPR) was 47.6% (10/21) and the live birth rate (LBR) was 38.1% (8/21). Per cycle, CPR and LBR were 37 and 31% following IVF-FP and 14 and 7% following IVM-FP, although these differences did not reach statistical significance. We report the fourth live birth after IVM-FP in cancer, and the first one after IVM embryo warming resulting from in vivo oocyte retrieval and IVM procedure.

CONCLUSION(S)

Both IVF-FP and IVM-FP are possible options for FP women with cancer. Due to minimal data regarding ultimate outcomes, further follow-up is needed.

Oocyte vitrification for elective fertility preservation: the past, present, and future

PURPOSE OF REVIEW

Oocyte cryopreservation is no longer experimental and one of its rapidly growing indications is elective fertility preservation. Currently there is no sufficient evidence to support its practice and therefore its place in IVF remains uncertain.

RECENT FINDINGS

Vitrification has superior post-thaw survival and fertilization outcomes compared with oocytes that were frozen with the slow-freeze technique. Oocyte vitrification produces similar IVF outcomes compared with fresh oocytes and is not associated with further obstetrical or perinatal morbidity. Undergoing elective oocyte cryopreservation between ages 35 and 37 will optimize live birth rates as well as cost effectiveness from mathematical models.

SUMMARY

In women who delay child bearing, elective oocyte cryopreservation in the mid 30s may be beneficial in terms of live birth rates and cost effectiveness. Prospective studies of women who have undergone oocyte cryopreservation and are now attempting conception are needed before official recommendations can be made regarding elective egg freezing.

No. 356-Egg Freezing for Age-Related Fertility Decline

OBJECTIVE

To provide a comprehensive review and evidence based recommendations for Canadian fertility centres that offer social egg freezing.

OUTCOMES

In social egg freezing cycles we evaluated thawed oocyte survival rates, fertilization rates, embryo quality, pregnancy rates, and live birth rates. We also review how these outcomes are impacted by age, ovarian reserve, and the number of eggs cryopreserved. Finally, we discuss the risks of social egg freezing, the alternatives, the critical elements for counselling and informed consent, and future reporting of egg freezing outcome data.

EVIDENCE

Published literature was reviewed through searches of MEDLINE and CINAHL using appropriate vocabulary and using key words ("oocyte cryopreservation," "egg freezing," "egg vitrification," "social egg freezing," and "elective egg freezing"). Results included systematic reviews, randomized controlled trials, controlled clinical trials, and observational studies. Expert opinion based on clinical experience, descriptive studies, or reports of expert committees was also included to discuss aspects of egg freezing not currently rigorously studied.

VALUES

The evidence obtained was reviewed and evaluated by the Clinical Practice Guideline (CPG) Committees of the Canadian Fertility and Andrology Society (CFAS) under the leadership of the principal authors.

BENEFITS, HARMS, AND COSTS

Implementation of this guideline should assist the clinician to develop an optimal approach in providing counselling for egg freezing while minimizing harm and improving patient outcomes during treatment.

VALIDATION

These guidelines have been reviewed and approved by the membership of the CFAS and by the CPG Committees of CFAS and The Society of Obstetricians and Gynaecologists of Canada (SOGC).

SPONSORS

CFAS and SOGC.

RECOMMENDATIONS

The Impact of Vitrification in Artificial Reproductive Technology Programmes

Cryopreservation is an integral part of the current methods of assisted reproductive technology (ART). In the past two decades, slow freezing has been replaced worldwide by vitrification due to its association with improved survival rates and clinical outcomes comparable to fresh embryo transfers. Successful embryo vitrification programmes have led to a significant reduction in the incidences of two major complications of ART: ovarian hyperstimulation syndrome and multiple gestations. Multiple embryo transfer cycles from the single ovum aspiration cycle have had a cumulative effect on the numbers of live births. Oocyte vitrification has also helped women to delay their pregnancies for medical or social reasons. This has made oocyte banking a viable option for better synchronisation of oocyte donation programmes. The emerging field of ovarian tissue vitrification has made fertility preservation possible for women undergoing gonadotoxic therapy. In this review, we have discussed the basic principles and methodology of slow freezing and vitrification along with its need and impact on ART.

RNA-Seq transcriptome profiling of mouse oocytes after in vitro maturation and/or vitrification

In vitro maturation (IVM) and vitrification have been widely used to prepare oocytes before fertilization; however, potential effects of these procedures, such as expression profile changes, are poorly understood. In this study, mouse oocytes were divided into four groups and subjected to combinations of in vitro maturation and/or vitrification treatments. RNA-seq and in silico pathway analysis were used to identify differentially expressed genes (DEGs) that may be involved in oocyte viability after in vitro maturation and/or vitrification. Our results showed that 1) 69 genes were differentially expressed after IVM, 66 of which were up-regulated. Atp5e and Atp5o were enriched in the most significant gene ontology term “mitochondrial membrane part”; thus, these genes may be promising candidate biomarkers for oocyte viability after IVM. 2) The influence of vitrification on the transcriptome of oocytes was negligible, as no DEGs were found between vitrified and fresh oocytes. 3) The MII stage is more suitable for oocyte vitrification with respect to the transcriptome. This study provides a valuable new theoretical basis to further improve the efficiency of in vitro maturation and/or oocyte vitrification.