The cumulative dose of gonadotropins used for controlled ovarian stimulation does not influence the odds of embryonic aneuploidy in patients with normal ovarian response

Total gonadotropin dose did not affect euploid blastocyst rates: an analysis of more than 19,000 oocytes

BACKGROUND

To evaluate whether increasing total gonadotropin (Gn) dose is associated with changes in euploid blastocyst rate in preimplantation genetic testing (PGT) oocytes.

METHODS

This retrospective cohort study was conducted between 2017 and 2022, and 19,246 oocytes were grouped and analyzed based on tri-sectional quantiles of total Gn doses.

SETTING

Single reproductive medical center.

SUBJECTS

All the patients who underwent PGT cycles, including PGT for aneuploidy, monogenic disorders, and structural rearrangements, were included.

EXPOSURE

Next-generation sequencing platforms for chromosomal analysis.

MAIN OUTCOME MEASURES

Blastocyst formation and euploid blastocyst rates.

RESULTS

In total, 19,246 oocytes and 5375 PGT blastocysts were analyzed. There were significant differences in blastocyst formation and euploid blastocyst rates among the groups classified according to tri-sectional quantiles of total Gn doses. Significant differences in age, body mass index (BMI), proportion of primary infertility, anti-Müllerian hormone (AMH) levels, number of oocytes retrieved, controlled ovarian stimulation (COS) regimen, type of Gn, and PGT category were observed among the three groups. After stratifying the analysis by age, BMI, infertility diagnosis, AMH levels, number of oocytes retrieved, PGT category, type of Gn, and COS regimen, significant differences were only seen in a small number of specific subgroups. Furthermore, the results of the multiple logistic regression analysis showed that the blastocyst formation and euploid blastocyst rates did not significantly increase or decrease with the total Gn dose, whether treated as a continuous variable or divided into three Gn groups as categorical variables. Notably, advancing age was a risk factor for blastocyst formation and euploid blastocyst rates. PGT for structural rearrangements was a risk factor for blastocyst formation and euploid blastocyst rates as compared with PGT for aneuploidy.

CONCLUSION

In the total PGT cycles, advancing age, and preimplantation genetic testing for structural rearrangements negatively affected blastocyst formation and euploid blastocyst rates; however, the total Gn dose did not affect blastocyst formation and euploid blastocyst rates.

The ovarian stimulation regimen does not affect aneuploidy or blastocyst rate

RESEARCH QUESTION

Could the total dose (<3000 IU or ≥3000 IU) and type of exogenous gonadotrophin (i.e. recombinant FSH and/or human menopausal gonadotrophin [HMG]) influence aneuploidy and blastulation rates and produce different reproductive outcomes?

DESIGN

This retrospective, observational, multicentre cohort study included a total of 8466 patients undergoing IVF using autologous oocytes and preimplantation genetic testing for aneuploidies. Participants were divided according to the dosage of total gonadotrophins and stratified by maternal age.

RESULTS

The aneuploidy rates, pregnancy outcomes and cumulative live birth rates (CLBR) were similar among women who received total gonadotrophin dosages of <3000 or ≥3000 IU. No statistical differences were reported in the blastulation rate with lower or higher gonadotrophin dosages. Women receiving a higher amount of HMG during ovarian stimulation had a lower aneuploidy rate (P = 0.02); when stratified according to age, younger women with a higher HMG dosage had lower aneuploidy rates (P< 0.001), while no statistical differences were observed in older women with higher or lower HMG dosages. No significant differences were observed in IVF outcomes or CLBR.

CONCLUSIONS

High doses of gonadotrophins were not associated with rate of aneuploidy. However, an increased fraction of HMG in younger women was associated with a lower aneuploidy rate. The study demonstrated that the total gonadotrophin dosage did not influence aneuploidy, reproductive outcomes or CLBR. The increased gonadotrophin and HMG dosages used for ovarian stimulation did not precede aneuploidy, and the use of HMG should be evaluated on a case-by-case basis, according to the individual's characteristics and infertility type.

Excessive Exogenous Gonadotropins and Genetic and Pregnancy Outcomes After Euploidy Embryo Transfer: A Secondary Analysis of a Randomized Clinical Trial

Importance

The safety of exogenous gonadotropin treatment, based on its effect on embryos and pregnancy outcomes, remains inconclusive.

Objective

To evaluate the associations of different doses and durations of gonadotropins with embryonic genetic status and pregnancy outcomes after euploid embryo transfer in couples with infertility.

Design, Setting, and Participants

This study was a post hoc analysis of a multicenter randomized clinical trial (RCT) conducted at 14 reproductive centers throughout China from July 2017 to June 2018 that evaluated the cumulative live birth rate with or without preimplantation genetic testing for aneuploidy (PGT-A) among couples with infertility and good prognosis. The PGT-A group from the original RCT was selected for secondary analysis. Patients were divided into 4 groups according to the total dosage of exogenous gonadotropins and treatment duration: group 1 (≤1500 IU and <10 days), group 2 (≤1500 IU and ≥10 days), group 3 (>1500 IU and <10 days), and group 4 (>1 500 IU and ≥10 days). Group 1 served as the control group. Data were analyzed from June through August 2023.

Interventions

Blastocyst biopsy and PGT-A.

Main outcomes and measures

The primary outcomes were embryonic aneuploidy, embryonic mosaicism, and cumulative live birth rates after euploid embryo transfer.

Results

A total of 603 couples (mean [SD] age of prospective mothers, 29.13 [3.61] years) who underwent PGT-A were included, and 1809 embryos were screened using next-generation sequencing. The embryo mosaicism rate was significantly higher in groups 2 (44 of 339 embryos [13.0%]; adjusted odds ratio [aOR], 1.69 [95% CI, 1.09-2.64]), 3 (27 of 186 embryos [14.5%]; aOR, 1.98 [95% CI, 1.15-3.40]), and 4 (82 of 651 embryos [12.6%]; aOR, 1.60 [95% CI, 1.07-2.38]) than in group 1 (56 of 633 embryos [8.8%]). There were no associations between gonadotropin dosage or duration and the embryo aneuploidy rate. The cumulative live birth rate was significantly lower in groups 2 (83 of 113 couples [73.5%]; aOR, 0.49 [95% CI, 0.27-0.88]), 3 (42 of 62 couples [67.7%]; aOR, 0.41 [95% CI, 0.21-0.82]), and 4 (161 of 217 couples [74.2%]; aOR, 0.53 [95% CI, 0.31-0.89]) than in group 1 (180 of 211 couples [85.3%]).

Conclusions and relevance

In this study, excessive exogenous gonadotropin administration was associated with increased embryonic mosaicism and decreased cumulative live birth rate after euploid embryo transfer in couples with a good prognosis. These findings suggest that consideration should be given to minimizing exogenous gonadotropin dosage and limiting treatment duration to improve embryo outcomes and increase the live birth rate.

Trial Registration

ClinicalTrials.gov Identifier: NCT03118141.

Effects of total gonadotropin dose on embryo quality and clinical outcomes with AMH stratification in IVF cycles: a retrospective analysis of 12,588 patients

BACKGROUND

Recent studies about the effect of gonadotropin (Gn) dose on the clinical outcomes of IVF are still controversial, and no studies have analyzed the relationship between Gn dose and embryo quality. Since AMH is a strong predictor of oocyte quality, we aim to evaluate the relationship between total Gn dose and embryo quality and clinical outcomes at different AMH levels in IVF cycles.

METHODS

A total of 12,588 patients were enrolled in the retrospective study. The included cycles were categorized by serum AMH levels (AMH ≤ 1 ng/ml, 1 ng/ml < AMH ≤ 3 ng/ml, 3 ng/ml < AMH ≤ 5 ng/ml, AMH > 5 ng/ml), total Gn dosage (< 1875 IU, 1875-3750 IU and ≥ 3750 IU) and female age (< 35 years and 35-42 years). The embryo quality and clinical outcomes were the measure outcomes.

RESULTS

The top-day3 embryos rate decreased with the increase of total Gn dose in nearly all age and AMH subgroups, but this trend was not obvious in the AMH > 5 ng/ml group and AMH ≤ 1 ng/ml group. The blastocyst formation rate and high-quality blastulation rate had a negative relationship with Gn does for women aged < 35 years in the AMH ≤ 5 ng/ml groups, except for the AMH > 5 ng/ml group (P < 0.001). However, when women were 35-42 years old, regardless of AMH levels, the blastocyst formation rate and high-quality blastulation rate decreased as Gn dose increased. Clinical outcomes (implantation rate, clinical pregnancy rate and live birth rate) decreased with the increase of Gn dose in all ages and AMH stratifications.

CONCLUSIONS

The total dose of Gn may have different effects on embryo quality at different serum AMH levels, and the negative effects of total dose of Gn on clinical outcomes may be realized by impairing both embryo quality and endometrium.

Correlation of self-reported racial background to euploidy status and live birth rates in assisted reproductive technology cycles

PURPOSE

To determine whether the embryonic euploidy rate and live birth outcomes following single, euploid embryo transfer (SEET) differ among women of self-reported racial and ethnic backgrounds.

METHODS

This retrospective cohort study included all infertile patients of different self-reported racial backgrounds who underwent In vitro fertilization (IVF) with preimplantation genetic testing for aneuploidy (PGT-A) and an autologous single euploid embryo transfer (SEET) from December 2015 to December 2019 at a single private and academic assisted reproduction technology center. Primary outcome measures included ploidy rates among different racial groups. Secondary outcomes included clinical pregnancy, clinical pregnancy loss, and live birth rates.

RESULTS

Five thousand five hundred sixty-two patients who underwent an IVF cycle with ICSI-PGT-A were included. A total of 24,491 blastocysts were analyzed. White participants had on average more euploid embryos and higher euploidy rates when compared to their counterparts (p ≤ 0.0001). However, after controlling for confounding factors, there was no association between race and the odds of having  a higher euploidy rate (aOR 1.31; 95% CI 0.63-2.17, p = 0.42). A total of 4949 patients underwent SEET. Pregnancy outcomes did not differ among patients of varying self-reported races.

CONCLUSIONS

Euploidy rates and pregnancy outcomes were comparable among patients of different racial backgrounds who underwent a SEET.

Maternal age and gonadotrophin elevation cooperatively decrease viable ovulated oocytes and increase ootoxicity, chromosome-, and spindle-misalignments: '2-Hit' and 'FSH-OoToxicity' mechanisms as new reproductive aging hypotheses

While there is consensus that advanced maternal age (AMA) reduces oocyte yield and quality, the notion that high FSH reduces oocyte quality and causes aneuploidy remains controversial, perhaps due to difficulties controlling the confounding variables of age and FSH levels. Here, contributions of age and gonadotrophin elevation were separately controlled using a mouse model of human female reproductive aging. Ovulated oocytes were collected from young and midlife mice after 0-, 2.6-, or 17-day treatment with the FSH analog equine chorionic gonadotrophin (eCG), to model both exogenous FSH elevation within a single treatment cycle (as in controlled ovarian stimulation (COS)), and chronic endogenous FSH elevation during multiple cycles (as in diminished ovarian reserve). After 17-day eCG, fewer total oocytes/mouse are ovulated in midlife than young mice, and a precipitous decline in viable oocytes/mouse is observed in midlife but not young mice throughout eCG treatment. eCG is potently ootoxic to ovulatory oocytes and strongly induces chromosome- and spindle-misalignments within 2.6 days of eCG in midlife, but only after 17 days in young mice. These data indicate that AMA increases susceptibility to multiple adverse effects of elevated FSH activity in ovulated oocytes, including declines in total and viable oocytes/mouse, and induction of ootoxicity and aneuploidy. Two hypotheses are proposed for underlying causes of infertility in women. The FSH OOToxicity Hypothesis ('FOOT Hypothesis') posits that high FSH is ootoxic to ovulatory oocytes and that FSH ootoxicity is a root cause of low pregnancy success rates in naturally cycling women with high FSH and IUI patients undergoing COS. The '2-Hit Hypothesis' posits that AMA increases susceptibility to FSH-induced ootoxicity and aneuploidy.

Progestin Primed Ovarian Stimulation (PPOS) protocol yields lower euploidy rate in older patients undergoing IVF

BACKGROUND

To explore if exogenous progestin required for progestin primed ovarian stimulation (PPOS) protocol compromises the euploidy rate of patients who underwent preimplantation genetic testing cycles when compared to those who received the conventional gonadotropin-releasing hormone (GnRH) antagonist protocol.

METHODS

This retrospective cohort study analyzed 128 preimplantation genetic testing for aneuploidy (PGT-A) cycles performed from January 2018 to December 2021 in a single university hospital-affiliated fertility center. Infertile women aged 27 to 45 years old requiring PGT-A underwent either PPOS protocol or GnRH-antagonist protocol with in-vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) for fertilization. Frozen embryo transfers were performed following each PGT-A cycle. Data regarding the two groups were analyzed using the Statistical Package for Social Sciences (SPSS) version 22.0 (SPSS Inc., Chicago, IL).

RESULTS

Patients who underwent PPOS treatment had significantly reduced blastocyst formation rate and euploidy rate compared to those who received the GnRH antagonist protocol. Subgroup-analysis was performed by stratifying patients' age into elder and young subgroups (elder: ≥ 38-year-old, young: < 38-year-old). In the elder sub-population, the blastocyst formation rate of the PPOS group was significantly lower than that of the GnRH-antagonist group (45.8 ± 6.1% vs. 59.9 ± 3.8%, p = 0.036). Moreover, the euploidy rate of the PPOS group was only about 20% of that of  the GnRH-antagonist group (5.4% and 26.7%, p = 0.006). In contrast, no significant differences in blastocyst formation rate (63.5 ± 5.7% vs. 67.1 ± 3.2%, p = 0.45) or euploidy rate (30.1% vs. 38.5%, p = 0.221) were observed in the young sub-population. Secondary outcomes, which included implantation rate, biochemical pregnancy rate, clinical pregnancy rate, live birth rate, and miscarriage rate, were comparable between the two treatment groups, regardless of age.

CONCLUSION

When compared to the conventional GnRH-antagonist approach, PPOS protocol could potentially reduce the euploidy rate in aging IVF patients. However, due to the retrospective nature of this study, the results are to be interpreted with caution. Before the PPOS protocol is widely implemented, further studies exploring its efficacy in larger populations are needed to define the optimal patient selection suitable for this method.

TRIAL REGISTRATION

Human Investigation and Ethical Committee of Chang Gung Medical Foundation (202200194B0).

Preimplantation Genetic Testing for Aneuploidy for Recurrent Pregnancy Loss and Recurrent Implantation Failure in Minimal Ovarian Stimulation Cycle for Women Aged 35-42 Years: Live Birth Rate, Developmental Follow-up of Children, and Embryo Ranking

This study was aimed at exploring the benefits of preimplantation genetic testing for aneuploidy (PGT-A) in ensuring a successful pregnancy in patients with recurrent pregnancy loss (RPL) caused by an abnormal number of chromosomes in the embryo and recurrent implantation failure (RIF). Thirty-two patients who underwent PGT-A (18 in the RIF protocol and 14 in the RPL protocol) were enrolled in the study, and 2556 patients who did not undergo PGT-A during the same in vitro fertilization (IVF) treatment period were enrolled as controls. All patients underwent minimal stimulation cycle IVF. In the RPL protocol, the live birth rate per embryo transfer (ET) and that per patient were higher with PGT-A (80.0% each) than without it (0% each; P = 0.0050), and the rate of miscarriages was lower with PGT-A than without it (20.0% vs. 100.0%, P = 0.0098). In the RIF protocol, there were no significant differences in the live birth rate per ET and in the rate of miscarriages between groups with and without PGT-A-90.0% vs. 69.2% (P = 0.2313) and 0% vs. 10.0% (P = 0.3297), respectively. None of the children whose mothers underwent PGT-A presented adverse findings at a 1.5-year developmental check-up. In conclusion, PGT-A in RPL is advantageous for improving the live birth rate per ET and that per patient in minimal stimulation cycle IVF; it reduces the rate of miscarriages. In addition, PGT-A might be more beneficial for embryo selection than the existing morphological grades of blastocysts, resulting in earlier conception.

Follicle-stimulating hormone (and luteinizing hormone) in ovarian stimulation: Does the dose matter for cycle success?

In this review, we have summarized the evolution in our understanding of a relevance of gonadotropin dosing for cycle outcomes in women attempting to conceive through the utilization of the in vitro fertilization technology.

Correlation of IVF outcomes and number of oocytes retrieved: a UK retrospective longitudinal observational study of 172 341 non-donor cycles

OBJECTIVE

How do numbers of oocytes retrieved per In vitro fertilisation (IVF) cycle impact on the live birth rate (LBR) and multiple gestation pregnancy (MGP) rates?

DESIGN

Retrospective observational longitudinal study.

SETTING

UK IVF clinics.

POPULATION

Non-donor IVF patients.

MAIN OUTCOME MEASURES

LBR per IVF cycle and MGP levels against number of oocytes retrieved into subgroups: 0, 1-5, 6-15, 16-25, 26-49 oocytes and 50+ oocytes. Relative risk (RR) and 95% CIs were calculated for each group against the intermediate responder with '6-15 oocytes collected'.

RESULTS

From 172 341 attempted fresh oocyte retrieval cycles, the oocyte retrieved was: 0 in 10 148 (5.9%) cycles from 9439 patients; 1-5 oocytes in 42 574 cycles (24.7%); 6-15 oocytes in 91 797 cycles (53.3%); 16-25 oocytes in 23 794 cycles (13.8%); 26-49 oocytes in 3970 cycles (2.3%); ≥50 oocytes in 58 cycles (0.033%). The LBRs for the 1-5, 6-15, 16-25 and 26-49 subgroups of oocytes retrieved were 17.2%, 32.4%, 35.3% and 18.7%, respectively. The RR (95% CI) of live birth in comparison to the intermediate group (6-15) for 1-5, 16-25 and 26-49 groups was 0.53 (0.52 to 0.54), 1.09 (1.07 to 1.11) and 0.58 (0.54 to 0.62), respectively. The corresponding MGP rates and RR were 9.2%, 11.0%, 11.4% and 11.3%, respectively and 0.83 (0.77 to 0.90), 1.04 (0.97 to 1.11) and 1.03 (0.84 to 1.26), respectively.

CONCLUSION

There was only limited benefit in LBR beyond the 6-15 oocyte group going to the 16-25 oocytes group, after which there was significant decline in LBR. The MGP risk was lower in 1-5 group.

The effect of ovarian stimulation on aneuploidy of early aborted tissues and preimplantation blastocysts: comparison of the GnRH agonist long protocol with the GnRH antagonist protocol

PURPOSE

To compare aneuploidy rates in early aborted tissues or blastocysts between in vitro fertilization (IVF) cycles after the gonadotropin-releasing hormone (GnRH) antagonist (GnRH-ant) protocol or the GnRH agonist (GnRH-a) long protocol.

METHODS

This was a retrospective cohort study from a university-affiliated fertility center. In total, 550 early miscarriage patients who conceived through IVF/intracytoplasmic sperm injection (ICSI) after receiving the GnRH-ant or GnRH-a long protocol were analyzed to compare aneuploidy rates in early aborted tissues. To compare aneuploidy rates in blastocysts, 404 preimplantation genetic testing for aneuploidy (PGT-A) cycles with the GnRH-ant protocol or GnRH-a long protocol were also analyzed.

RESULTS

For early miscarriage patients who conceived through IVF/ICSI, compared to the GnRH-a long protocol group, the GnRH-ant protocol group had a significantly higher rate of aneuploidy in early aborted tissues (48.51% vs. 64.19%). Regarding PGT-A cycles, the rate of blastocyst aneuploidy was significantly higher in the GnRH-ant protocol group than the GnRH-a long protocol group (39.69% vs. 52.27%). After stratification and multiple linear regression, the GnRH-ant regimen remained significantly associated with an increased risk of aneuploidy in early aborted tissues and blastocysts [OR (95% CI) 1.81 (1.21, 2.71), OR (95% CI) 1.65 (1.13, 2.42)]. Furthermore, the blastocyst aneuploidy rate in the GnRH-ant protocol group was significantly higher but only in young and normal ovarian responders [OR (95% CI) 5.07 (1.99, 12.92)].

CONCLUSION

Compared to the GnRH-a long protocol, the GnRH-ant protocol is associated with a higher aneuploidy rate in early aborted tissues and blastocysts. These results should be confirmed in a multicenter, randomized controlled trial.

Controlled ovarian hyperstimulation parameters are not associated with de novo chromosomal abnormality rates and clinical pregnancy outcomes in preimplantation genetic testing

OBJECTIVE

This study aimed to determine whether controlled ovarian hyperstimulation (COH) parameters influence the incidence of de novo chromosomal abnormalities (> 4 Mb) in blastocysts and, thus, clinical pregnancy outcomes in preimplantation genetic testing (PGT).

METHODS

Couples who underwent preimplantation genetic testing for structural chromosome rearrangements (PGT-SR) and monogenic disorders (PGT-M) were included in this study. The relationships of maternal age, paternal age, stimulation protocol, exogenous gonadotropin dosage, duration of stimulation, number of oocytes retrieved and estradiol (E₂) levels on human chorionic gonadotropin (hCG) trigger day with the incidence of de novo chromosomal abnormalities were assessed. Blastocysts were biopsied, and nuclear DNA was sequenced using next-generation sequencing (NGS). Clinical pregnancy outcomes after single euploid blastocyst transfers under different COH parameters were assessed.

RESULTS

A total of 1,710 and 190 blastocysts were biopsied for PGT-SR and PGT-M, respectively. The rate of de novo chromosomal abnormalities was found to increase with maternal age (p< 0.001) and paternal age (p = 0.019) in the PGT-SR group. No significant differences in the incidence of de novo chromosomal abnormalities were seen for different maternal or paternal age groups between the PGT-SR and PGT-M groups (p > 0.05). Stratification analysis by gonadotropin dosage, stimulation protocol, duration of stimulation, number of retrieved oocytes and E₂ levels on hCG trigger day revealed that de novo chromosomal abnormalities and clinical pregnancy outcomes were not correlated with COH parameters after adjusting for various confounding factors.

CONCLUSION

The rate of de novo chromosomal abnormalities was found to increase with maternal or paternal age. COH parameters were found to not influence the incidence of de novo chromosomal abnormalities or clinical pregnancy outcomes.

The putative roles of FSH and AMH in the regulation of oocyte developmental competence: from fertility prognosis to mechanisms underlying age-related subfertility

BACKGROUND

Fertility loss during female ageing is associated with increasing basal FSH and decreasing anti-Müllerian hormone (AMH) concentrations, together with compromised oocyte quality, presumably due to increased oxidative stress (OS) and DNA damage, as well as reduced metabolic and meiotic competences. Basal FSH and AMH circulatory concentrations have been broadly utilized as IVF success predictors, regardless of fluctuations in prognostic accuracy; basal FSH and AMH perform better in pre-advanced maternal age (AMA: >35 years) and AMA patients, respectively. The relationships between FSH and AMH intrafollicular levels and IVF outcomes suggest, nevertheless, that both hormones regulate oocyte competence, supporting the hypothesis that changes in FSH/AMH levels cause, at least in part, oocyte quality degradation during ageing. To understand the reasons behind the fluctuations in FSH and AMH prognostic accuracies and to clarify their participation in mechanisms determining oocyte competence and age-related subfertility, a deeper knowledge of the regulation of FSH and AMH intrafollicular signalling during the female reproductive lifespan, and of their effects on the cumulus-oocyte complex, is required.

OBJECTIVE AND RATIONALE

An extensive body of information on the regulation of FSH and AMH intrafollicular availability and signalling, as well as on the control of folliculogenesis and oocyte metabolism, has been accumulated. However, these datasets have been explored within the relatively narrow boundaries of their specific subjects. Given the aforementioned gaps in knowledge and their clinical relevance, herein we integrate clinical and basic data, within a wide biological perspective, aiming to shed light on (i) the reasons for the variability in the accuracy of serum FSH and AMH as fertility markers, and on (ii) the potential roles of these hormones in mechanisms regulating oocyte quality, particularly those associated with ageing.

SEARCH METHODS

The PubMed database encompassing the period between 1960 and 2021 was searched. Principal search terms were FSH, FSH receptor, AMH, oocyte, maternal age, cumulus, transzonal projections (TZPs), actin, OS, redox, reactive oxygen species, mitochondria, DNA damage, DNA repair, aneuploidy, spindle, meiosis, gene expression, transcription, translation, oocyte secreted factors (OSFs), cAMP, cyclic guanosine monophosphate, natriuretic peptide C, growth differentiation factor 9, bone morphogenetic protein 15 and fibroblast growth factor.

OUTCOMES

Our analysis suggests that variations in the accuracy of fertility prognosis reflect a modest association between circulatory AMH levels and oocyte quality as well as increasing basal FSH inter-cycle variability with age. In addition, the basic and clinical data articulated herein support the hypothesis that increased intrafollicular FSH levels, as maternal age advances, may override the physiological protective influences of AMH and OSFs against excessive FSH signalling in cumulus cells. This would result in the disruption of oocyte homeostasis via reduced TZP-mediated transfer of cumulus-derived molecules essential for meiotic competence, gene expression, redox activity and DNA repair.

WIDER IMPLICATIONS

In-depth data analysis, encompassing a wide biological perspective has revealed potential causative mechanisms of age-related subfertility triggered by alterations in FSH/AMH signalling during the female reproductive life. Insights from new mechanistic models arising from this analysis should contribute to advancing our comprehension of oocyte biology in humans and serve as a valuable reference for novel AMA subfertility treatments aimed at improving oocyte quality through the modulation of AMH/FSH action.

Higher Doses of FSH Used for Superovulation Do Not Adversely Affect Embryonic Ploidy: A Randomized Controlled Trial (STimulation Resulting in Embryonic Aneuploidy using Menopur (STREAM) Trial)

Research Question: Does the dose of gonadotropin used for superovulation in IVF affect the proportion of euploid blastocysts obtained after fertilization?

Study Design: Multicentre randomized controlled trial recruiting 57 women who were treated with ovarian stimulation using either 150 or 300 IU Menopur per day. Both groups received GnRH antagonist from day 5 of ovarian stimulation and final oocyte maturation was induced using a leuprolide GnRH (gonadotropin releasing hormone) agonist trigger when three or more follicles reached 17 mm diameter. Oocyte collection was scheduled 36–38 hours post trigger. In vitro fertilization (IVF) or Intracytoplasmic Sperm Injection (ICSI) were performed according to individual unit protocol and embryos were cultured to blastocyst stage. A trophectoderm biopsy was performed on day 5 of embryo culture and used for preimplantation genetic testing for aneuploidy. Euploid embryos were transferred in subsequent frozen embryo transfer cycles with appropriate endometrial preparation.

Results: The number of oocytes obtained from women randomized to 150 IU Menopur was between 3 and 17 (mean = 9), whereas the number of oocytes obtained from women randomized to 300 IU Menopur was between 3 and 24 (mean = 11). There was a positive linear relationship between serum AMH concentration and oocyte yield in both the 150 and 300 IU Menopur groups ([Formula: see text] = 0.3359, [Formula: see text] = 0.1129 and [Formula: see text] = 0.3741, [Formula: see text] = 0.1399). The percentage of euploid to aneuploid embryos in the 150 IU Menopur group was 63% and in the 300 IU Menopur group, the proportion was 75%, which was not significantly different ([Formula: see text] = 0.17).

Conclusion: The higher dose ovarian stimulation protocol did not significantly increase the number of oocytes retrieved, nor did the higher dose protocol reduce the proportion of euploid embryos created. This study does not support the hypothesis that use of higher doses of gonadotropin for ovarian stimulation results in a reduction in the proportion of euploid embryos obtained after IVF.

Social Freezing: Pressing Pause on Fertility

Increasing numbers of women are undergoing oocyte or tissue cryopreservation for medical or social reasons to increase their chances of having genetic children. Social egg freezing (SEF) allows women to preserve their fertility in anticipation of age-related fertility decline and ineffective fertility treatments at older ages. The purpose of this study was to summarize recent findings focusing on the challenges of elective egg freezing. We performed a systematic literature review on social egg freezing published during the last ten years. From the systematically screened literature, we identified and analyzed five main topics of interest during the last decade: (a) different fertility preservation techniques, (b) safety of freezing, (c) usage rate of frozen oocytes, (d) ethical considerations, and (e) cost-effectiveness of SEF. Fertility can be preserved for non-medical reasons through oocyte, embryos, or ovarian tissue cryopreservation, with oocyte vitrification being a new and optimal approach. Elective oocyte cryopreservation is better accepted, supports social gender equality, and enhances women's reproductive autonomy. Despite controversies, planned oocyte cryopreservation appears as a chosen strategy against age-related infertility and may allow women to feel that they are more socially, psychologically, and financially stable before motherhood.

Cytogenetic Analysis of the Products of Conception After Spontaneous Abortion in the First Trimester

In the present study, we retrospectively recruited 340 patients who underwent spontaneous abortions to investigate chromosomal abnormalities of the conception products in the first trimester. We also performed a relevant analysis of clinical factors. Of these patients, 165 had conception products with chromosomal abnormalities, including 135 aneuploidies, 11 triploidies, 10 complex abnormalities, and 9 segmental aneuploidies. The most common abnormal chromosomes were chromosome 16 in the embryo-transfer group and sex chromosomes in the natural-conception group. The most common abnormal chromosomes in all analyzed maternal age groups were sex chromosomes, 16, and 22. The chromosomal abnormality incidence was related to age and number of spontaneous abortions (both p < 0.05), but not to number of pregnancies, deliveries, induced abortions, or methods of conception (all p > 0.05). The rates of abnormality for chromosomes 12, 15, 20, and 22 increased with age, while the rates for chromosomes 6, 7, 13, and X decreased. In all age groups, aneuploidy was by far the most common abnormality; however, the low-incidence distributions of chromosomal abnormalities were entirely different. Overall, chromosomal aneuploidy was the primary cause of pregnancy loss in the first trimester, and low-frequency abnormalities differed across age subgroups. Chromosomal aberrations were found to be related to maternal age and spontaneous abortion, but not all chromosomal abnormalities increased with age.

Individualized ovarian stimulation in IVF/ICSI treatment: it is time to stop using high FSH doses in predicted low responders

In IVF/ICSI treatment, the FSH starting dose is often increased in predicted low responders from the belief that it improves the chance of having a baby by maximizing the number of retrieved oocytes. This intervention has been evaluated in several randomized controlled trials, and despite a slight increase in the number of oocytes—on average one to two more oocytes in the high versus standard dose group—no beneficial impact on the probability of a live birth has been demonstrated (risk difference, −0.02; 95% CI, −0.11 to 0.06). Still, many clinicians and researchers maintain a highly ingrained belief in ‘the more oocytes, the better’. This is mainly based on cross-sectional studies, where the positive correlation between the number of retrieved oocytes and the probability of a live birth is interpreted as a direct causal relation. If the latter would be present, indeed, maximizing the oocyte number would benefit our patients. The current paper argues that the use of high FSH doses may not actually improve the probability of a live birth for predicted low responders undergoing IVF/ICSI treatment and exemplifies the flaws of directly using cross-sectional data to guide FSH dosing in clinical practice. Also, difficulties in the de-implementation of the increased FSH dosing strategy are discussed, which include the prioritization of intermediate outcomes (such as cycle cancellations) and the potential biases in the interpretation of study findings (such as confirmation or rescue bias).

Oocyte or embryo number needed to optimize live birth and cumulative live birth rates in mild stimulation IVF cycles

RESEARCH QUESTION

How many oocytes or embryos are needed to optimize the live birth rate (LBR) per cycle and cumulative LBR (CLBR) following mild stimulation IVF (MS-IVF) in women with uncompromised ovarian reserve?

DESIGN

Retrospective analysis of a 4-year database of five fertility centres. The study population included women with normal/high ovarian reserve, who underwent autologous MS-IVF (daily ≤150 IU gonadotrophin) with fresh and subsequent frozen embryo transfer(s) (FET) from surplus embryos. Only the first cycle of each patient was included. Cycles with >150 IU daily average of gonadotrophin were excluded. 'Freeze-all embryo' (FAE) cycles were analysed separately.

RESULTS

A total of 862 consecutive cycles fulfilled the inclusion criteria; 592 were eligible for fresh embryo transfer, 239 had non-elective 'freeze-all' cycles. Median age (25-75th percentile) of women who had fresh embryo transfer was 35 (32-37) years, median antral follicle count 19 (14-28) and anti-Müllerian hormone 19.2 (13-28.9) pmol/l. LBR/fresh cycle and CLBR inclusive of FAE cycles in the <35, 35-37, 38-39 and 40-42 year age groups were 37.8% and 45.1%, 36.0% and 41.6%, 18.4% and 29.1%, and 8.9% and 18.1%, respectively. The LBR following fresh embryo transfer plateaued after nine oocytes (40.3%) or four embryos (40.8%). The CLBR optimized when 12 oocytes (42.9%) or nine embryos (53.8%) were obtained. The LBR per oocyte peaked in women under 35 years when <5 oocytes were retrieved (11.4%), then declined with age and with higher oocyte yield. There were no cases of severe ovarian hyperstimulation syndrome (OHSS).

CONCLUSION

Nine oocytes, or four embryos, can optimize fresh transfer cycle LBR in MS-IVF. The CLBR are optimized with 12 oocytes, or nine embryos in predicted normal responders, while safeguarding against OHSS.

Euploidy rates of embryos in young patients with good and low prognosis according to the POSEIDON criteria

RESEARCH QUESTION

Does an association exist between ovarian reserve, ovarian response and embryonic euploidy in female patients under age 35 years?

DESIGN

This was a retrospective analysis of intracytoplasmic sperm injection and preimplantation genetic testing for aneuploidies cycles among patients enrolled at Bahceci Fulya IVF Center between January 2016 and August 2019. A total of 133 patients in POSEIDON group 1 (suboptimal responder; female age <35 years, antral follicle count [AFC] ≥5, number of oocytes retrieved <10) (group A), 133 patients in POSEIDON group 3 (expected low responder; female age <35 years, AFC <5) (group B) and 323 in the non-low-prognosis group (female age <35 years, AFC ≥5 and number of oocytes retrieved >9) (group C) were included.

RESULTS

There was no significant difference in euploidy rate per embryo among the three groups (61.7% [145/235] for group A versus 53.5% [68/127] for group B versus 62% [625/1008] for group C; P = 0.13). The cancellation rate in cycles without a euploid blastocyst was significantly lower in group C than groups A and B (8.4% versus 12.8% and 16.5%; P = 0.034). Multivariate regression analysis indicated that the ovarian response group did not significantly affect the probability of obtaining a euploid embryo. Trophectoderm score 'C' (odds ratio 0.520, P = 0.007) and inner cell mass score 'C' (odds ratio 0.480, P < 0.001) were associated with a decreased probability of obtaining a euploid embryo.

CONCLUSIONS

These results confirm that POSEIDON group 1 and group 3 and non-low-prognosis patients have different probabilities of euploid embryos being obtained per cycle. However, euploidy rates per embryo are not affected by the patient's ovarian reserve and response.

Effect of ovarian stimulation on embryo aneuploidy and mosaicism rate

There is a high incidence of chromosome abnormalities in human embryos that leads to a failed IVF cycle. Different studies have shown that maternal age is the determining factor in the appearance of chromosomal alterations in the embryo. However, the possible influence of ovarian stimulation on oocyte and embryo aneuploidies and mosaicism is controversial. A retrospective study was carried out in which 835 embryos from 280 couples undergoing reproductive treatment using their oocytes were chromosomally analyzed. A binary logistic regression analysis was performed to evaluate the relationship between different parameters characterizing controlled ovarian stimulation (COS) and the rate of aneuploidy and embryonic mosaicism. The embryo aneuploidy rate showed no association with the use of oral contraceptives, type, total and daily doses of gonadotropins, stimulation protocol type, and drugs used for ovulation trigger (p > 0.05). In contrast, the duration of the ovarian stimulation treatment was correlated with the aneuploidy rate: patients requiring more days of stimulation presented a lower rate of aneuploid embryos (p = 0.015). None of the variables studied showed any association with the rate of embryo mosaicism. However, the duration of COS showed association with the appearance of aneuploidy, suggesting that faster recruitment could be deleterious for those reassuming meiosis, yielding more abnormal karyotype.Abbreviations: IVF: in vitro fertilization; COS: controlled ovarian stimulation; PGT-A: preimplantation genetic test for aneuploidy; hCG: human chorionic gonadotropin; GnRH: gonadotropin-releasing hormone; LH: luteinizing hormone; FSH: follicle-stimulating hormone; NGS: next-generation sequencing; a-CGH: comparative genomic hybridization; TUNEL: Terminal transferase dUTP Nick End Labeling; FISH: fluorescent in situ hybridization.

Analysis of bovine blastocysts indicates ovarian stimulation does not induce chromosome errors, nor discordance between inner-cell mass and trophectoderm lineages

Contemporary systems for oocyte retrieval and culture of both cattle and human embryos are suboptimal with respect to pregnancy outcomes following transfer. In humans, chromosome abnormalities are the leading cause of early pregnancy loss in assisted reproduction. Consequently, pre-implantation genetic testing for aneuploidy (PGT-A) is widespread and there is considerable interest in its application to identify suitable cattle IVP embryos for transfer. Here we report on the nature and extent of chromosomal abnormalities following transvaginal follicular aspiration (OPU) and IVP in cattle. Nine sexually mature Holstein heifers underwent nine sequential cycles of OPU-IVP (six non-stimulated and three stimulated cycles), generating 459 blastocysts from 783 oocytes. We adopted a SNP-array approach normally employed in genomic evaluations but reanalysed (Turner et al., 2019; Theriogenology125: 249) to detect levels of meiotic aneuploidy. Specifically, we asked whether ovarian stimulation increased the level of aneuploidy in either trophectoderm (TE) or inner-cell mass (ICM) lineages of blastocysts generated from OPU-IVP cycles. The proportion of Day 8 blastocysts of inseminated was greater (P < 0.001) for stimulated than non-stimulated cycles (0.712 ± 0.0288 vs. 0.466 ± 0.0360), but the overall proportion aneuploidy was similar for both groups (0.241 ± 0.0231). Most abnormalities consisted of meiotic trisomies. Twenty in vivo derived blastocysts recovered from the same donors were all euploid, thus indicating that 24 h of maturation is primarily responsible for aneuploidy induction. Chromosomal errors in OPU-IVP blastocysts decreased (P < 0.001) proportionately as stage/grade improved (from 0.373 for expanded Grade 2 to 0.128 for hatching Grade 1 blastocysts). Importantly, there was a high degree of concordance in the incidence of aneuploidy between TE and ICM lineages. Proportionately, 0.94 were "perfectly concordant" (i.e. identical result in both); 0.01 were imperfectly concordant (differing abnormalities detected); 0.05 were discordant; of which 0.03 detected a potentially lethal TE abnormality (false positives), leaving only 0.02 false negatives. These data support the use of TE biopsies for PGT-A in embryos undergoing genomic evaluation in cattle breeding. Finally, we report chromosome-specific errors and a high degree of variability in the incidence of aneuploidy between donors, suggesting a genetic contribution that merits further investigation.

Medical research and reproductive medicine in an ethical context: a critical commentary on the paper dealing with uterine lavage published by Munné et al

A recent study published in Human Reproduction claimed that uterine lavage offers a non-surgical, minimally invasive strategy for the recovery of human embryos from fertile women who do not want or need IVF for medical reasons but who desire preimplantation genetic testing (PGT) for embryos. To prove this hypothesis, the researchers recruited dozens of young Mexican women. The prospective oocyte donors underwent ovarian stimulation to induce the production of multiple mature oocytes. Subsequently, these women were inseminated by donor semen. A few days later, the developing embryos were collected by uterine lavage (uterine flushing) and subjected to genetic testing for aneuploidies (PGT-A). Oocyte donors with persistently elevated hCG levels, indicating the implantation of one or more embryos after uterine lavage, had to undergo uterine curettage and/or treatment with methotrexate. A critical opinion paper discussing the aforementioned study was published by De Santis and colleagues and has raised critical issues that are largely technical in nature. However, this opinion paper neglects-from our point of view-critical issues of the Mexican study regarding ethical principles and moral standards in human research. These aspects are summarized below.

Differential impact of controlled ovarian hyperstimulation on live birth rate in fresh versus frozen embryo transfer cycles: a Society for Assisted Reproductive Technology Clinic Outcome System study

OBJECTIVE

To study the impact of both controlled ovarian hyperstimulation (COH) length and total gonadotropin (GN) dose individually and in concert on live birth rates (LBR) in both fresh and freeze-all in vitro fertilization embryo transfer (IVF-ET) cycles.

DESIGN

Historical cohort study.

SETTING

Not applicable.

PATIENT(S)

The U.S. national database from the Society of Assisted Reproductive Technology Clinic Outcome Reporting System from 2014 to 2015 was used to identify patients undergoing autologous GN stimulation IVF cycles with the use of GnRH antagonist-based suppression protocols where a single embryo transfer was performed as part of a fresh IVF-ET cycle (fresh, n = 14,866) or the first frozen embryo transfer after a freeze-all cycle (frozen, n = 2,964), and not including preimplantation genetic testing cycles. The patients' demographic and cycle characteristics, duration of COH, total GN dose, and pregnancy outcomes were extracted. Binomial regression models estimated trend and relative risk of live birth with respect to days of stimulation and total GN dose singularly, and after adjustment for a priori confounders including age, parity, body mass index, diagnosis, and maximum follicle-stimulating hormone in both fresh and frozen embryo transfer cycles. Both days of stimulation and total GN dose were then added to the multivariate model to show whether they were independently associated with LBR.

INTERVENTION(S)

Not applicable.

MAIN OUTCOME MEASURE(S)

Live birth rate.

RESULTS

In both fresh and frozen cycles, length of COH was significantly associated with total GN dose. On univariate analysis, LBR decreased significantly with increasing length of stimulation and increasing total GN dose in both fresh and frozen cycles. On multivariable analysis including both days of stimulation and total GN dose, days of stimulation was no longer significantly correlated with LBR, whereas total GN dose remained significantly correlated with LBR in fresh cycles only. When total GN doses ranging from <2,000 IU through 5,000 IU to >5,000 IU were compared, a significant improvement in live birth rate was noted with lower total GN doses. Specifically, GN doses <2,000 IU had a 27% higher rate of live birth compared with GN dose >5,000 IU. For GN dose groups up to 4,000 IU, the estimated effect on LBR was similar. There was a marginal improvement (13%) in LBR with GN doses of 4,000 IU to 5,000 IU compared with >5,000 IU. When the multivariate model was applied to the frozen cycles, neither total GN dose nor days of stimulation was significantly associated with LBR.

CONCLUSIONS

High total GN dose but not prolonged COH is associated with decreasing LBRs in fresh cycles, whereas neither factor significantly affects LBR in frozen cycles. Consideration should be given to minimizing the total GN dose when possible in fresh autologous cycles, either by decreasing the daily dose or by limiting the length of stimulation to improve LBRs. In freeze-all cycles, the use of higher GN doses does not seem to adversely affect the LBR of the first frozen embryo transfer. High total GN dose likely exerts a negative impact on the endometrium and/or oocyte/embryo unrelated to the length of stimulation. The differential effect of total GN dose on LBR in fresh and frozen cycles may imply a greater impact exerted on the endometrium rather than the oocyte.

Total follicle stimulating hormone dose is negatively correlated with live births in a donor/recipient model with fresh transfer: an analysis of 8,627 cycles from the Society for Assisted Reproductive Technology Registry

OBJECTIVE

Oocyte donation has optimized our understanding of ovarian stimulation. Increasing the follicle-stimulating hormone (FSH) dose has been shown to adversely affect live birth rates in autologous cycles. Our objective is to assess whether this relationship holds true within the donor/recipient population.

DESIGN

Retrospective cohort study.

SETTING

Not applicable.

PATIENTS

Data from 2014-2016 included 8,627 fresh donor cycles.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Live birth, clinical pregnancy, and miscarriage rates.

RESULTS

The mean donor age ± standard deviation (SD) was 25.8 ± 2.8 years. Donors underwent a median of 16 days (interquartile range [IQR] 12, 19) of stimulation with a median (IQR) total FSH dose and daily dose of 2,350.0 (1,800.0, 3,025.0) and 153.8 (113.2, 205.0) IU, respectively. The live birth rate was 56.7% per transfer. For every 500-unit increase in FSH dose, there was a 3% reduction in the odds of a live birth (odds ratio [OR] 0.97; 95% confidence interval 0.95, 0.99), and a 3% reduction in the odds of a clinical pregnancy (OR 0.97; 95% confidence interval 0.95, 0.99). Days of stimulation and average daily dose were not significantly associated with live birth or clinical pregnancy. No significant association was found between miscarriage rates and total FSH dose, days of stimulation, or average daily dose.

CONCLUSION

This is a novel report of a negative association of total FSH dosage on fresh IVF live births, performed in the donor population to control for oocyte source and endometrial receptivity.

Novel Physiology and Definition of Poor Ovarian Response; Clinical Recommendations

Poor ovarian response (POR) to controlled ovarian stimulation (OS) presents a major challenge in assisted reproduction. The Bologna criteria represented the first serious attempt to set clear criteria for the definition of POR. However, the Bologna criteria were questioned because of the persistent heterogeneity among POR patients and the inability to provide management strategies. Based on these facts, a more recent classification, the POSEIDON (Patient-Oriented Strategies Encompassing IndividualizeD Oocyte Number) classification, was developed to provide a homogeneous and refined definition of POR that significantly reduces the heterogeneity of the Bologna criteria definition of POR and helps in the clinical handling and counseling of patients. In this review, we discuss the impact of the POSEIDON classification on the clinical management of patients with POR.

Analysis of the Number of Euploid Embryos in Preimplantation Genetic Testing Cycles With Early-Follicular Phase Long-Acting Gonadotropin-Releasing Hormone Agonist Long Protocol

Studies have shown that early-follicular phase long-acting gonadotropin-releasing hormone (GnRH) agonist long protocol (EFLL), a popular controlled ovarian hyperstimulation protocol widely used in China, leads to higher rates of implantation and clinical pregnancy, as well as lower rates of spontaneous abortion and ectopic pregnancy in patients undergoing in vitro fertilization treatment. However, the impact of EFLL on euploid embryos and its underlying mechanisms remain unclear. To address these gaps of knowledge, we conducted a retrospective comparative study of 310 preimplantation genetic testing (PGT) cycles with a total of 1,541 embryos using the EFLL protocol or midluteal short-acting GnRH agonist long protocol (MLSL). Patients were matched by PGT subtype [aneuploidies (PGT-A) vs. PGT for chromosomal structural rearrangements (PGT-SR)], age (±2 years), and body mass index (±1 kg/m²). For PGT-A, there was no significant difference in the number of euploid embryos (1.80 ± 1.47 for EFLL vs. 1.84 ± 2.03 for MLSL, p > 0.05) or the rate of euploidy (44.6 vs. 36.9%, p > 0.05). For PGT-SR, the number of euploid embryos in the EFLL group was significantly higher than that in the MLSL group (1.76 ± 1.54 vs. 1.21 ± 1.24, p < 0.05). A higher euploidy rate was also observed with the EFLL protocol compared with that obtained in MLSL (31.9 vs. 25.7%), although the difference was not statistically significant (p > 0.05). Compared with the MLSL protocol, more euploid embryos were achieved when using the EFLL protocol in PGT-SR, demonstrating the value in PGT-SR. To the best of our knowledge, this study is the first one to compare embryonic outcomes between EFLL and MLSL, providing key insights into the clinical application of EFLL in PGT cycles. In the light of the limited sample size of our study, we recommend that these questions be explored using a larger prospective study.

Multinucleation in Day Two Embryos Is Not Associated with Multinucleation in Sibling Embryos After Freezing and Thawing

BACKGROUND

Multinucleated embryos exhibit impaired implantation potential, but whether the presence of multinucleated embryos in an embryo cohort reflects the quality of the entire cohort is controversial. No data exists on multinucleation rate among frozen-thawed embryos.

METHODS

De novo multinucleation and the number of multinucleated embryos on day two of embryo culture before freezing (D2) (n=415), at thawing (D2t) (n=320) and after an overnight culture after thawing (D3t) (n=265) was recorded. Associations between multinucleation before and after cryopreservation, female age and ovarian sensitivity to hormonal stimulation were assessed.

RESULTS

The occurrence of at least one multinucleated embryo per embryo cohort was 62.4% on D2, 16.3% on D2t and 31.7% on D3t. The presence of multinucleated embryos prior to freezing was not associated with de novo multinucleation during post-thaw culture (p=0.845). On D2, multinucleation was high in young women, irrespective of the number of collected oocytes (p=0.702). In older age groups, multinucleation was highest if >17 oocytes were obtained (p<0.001) and the odds for multinucleation was the lowest if the consumption of recombinant follicle-stimulating hormone was >238 IU/oocyte (In the age group of 30-35 years OR 0.25 [0.13-0.47], and the age group of 36-40 years OR 0.35 [0.20-0.63].

CONCLUSION

Multinucleation is commonly seen in embryos and good-quality day two embryo cohorts before freezing. The presence of multinucleated embryos prior to freezing does not illustrate multinucleation in sibling embryos after thawing. Embryo multinucleation is associated with factors related to good prognosis in assisted reproduction treatments.

Ovarian stimulation for freeze-all IVF cycles: a systematic review

BACKGROUND

Freeze-all IVF cycles are becoming increasingly prevalent for a variety of clinical indications. However, the actual treatment objectives and preferred treatment regimens for freeze-all cycles have not been clearly established.

OBJECTIVE AND RATIONALE

We aimed to conduct a systematic review of all aspects of ovarian stimulation for freeze-all cycles.

SEARCH METHODS

A comprehensive search in Medline, Embase and The Cochrane Library was performed. The search strategy included keywords related to freeze-all, cycle segmentation, cumulative live birth rate, preimplantation genetic diagnosis, preimplantation genetic testing for aneuploidy, fertility preservation, oocyte donation and frozen-thawed embryo transfer. We included relevant studies published in English from 2000 to 2018.

OUTCOMES

Our search generated 3292 records. Overall, 69 articles were included in the final review. Good-quality evidence indicates that in freeze-all cycles the cumulative live birth rate increases as the number of oocytes retrieved increases. Although the risk of severe ovarian hyperstimulation syndrome (OHSS) is virtually eliminated in freeze-all cycles, there are certain risks associated with retrieval of large oocyte cohorts. Therefore, ovarian stimulation should be planned to yield between 15 and 20 oocytes. The early follicular phase is currently the preferred starting point for ovarian stimulation, although luteal phase stimulation can be used if necessary. The improved safety associated with the GnRH antagonist regimen makes it the regimen of choice for ovarian stimulation in freeze-all cycles. Ovulation triggering with a GnRH agonist almost completely eliminates the risk of OHSS without affecting oocyte and embryo quality and is therefore the trigger of choice. The addition of low-dose hCG in a dual trigger has been suggested to improve oocyte and embryo quality, but further research in freeze-all cycles is required. Moderate-quality evidence indicates that in freeze-all cycles, a moderate delay of 2–3 days in ovulation triggering may result in the retrieval of an increased number of mature oocytes without impairing the pregnancy rate. There are no high-quality studies evaluating the effects of sustained supraphysiological estradiol (E2) levels on the safety and efficacy of freeze-all cycles. However, no significant adverse effects have been described. There is conflicting evidence regarding the effect of late follicular progesterone elevation in freeze-all cycles.

WIDER IMPLICATIONS

Ovarian stimulation for freeze-all cycles is different in many aspects from conventional stimulation for fresh IVF cycles. Optimisation of ovarian stimulation for freeze-all cycles should result in enhanced treatment safety along with improved cumulative live birth rates and should become the focus of future studies.

Duration of ovarian stimulation is predictive of in-vitro fertilization outcomes

BACKGROUND

The aim of this study is to evaluate the effect of ovarian stimulation duration on oocyte/embryo development and pregnancy outcome in an in-vitro fertilization cycle (IVF).

METHODS

Retrospective cohort study performed at University of South Florida reproductive center between January 2011 and December 2016. A total of 690 sub-fertile women who underwent autologous IVF cycle were included for analysis. The outcomes were compared between patients undergoing ovarian stimulation for ≤8 days and >8 days. Data was further categorized into accelerated stimulation group (≤8 days), normal duration stimulation group (9-12 days), and delayed stimulation group (≥13 days). Primary outcome was live birth rate. Secondary outcomes include oocyte development and embryo characteristics.

RESULTS

A total of 69 (10%) and 621 (90%) patients underwent ovarian stimulation for ≤8 and >8 days, respectively. Ovarian stimulation for >8 days had 2.1 times higher odds of live birth (35.7% vs. 20.8%, 95% CI: 1.02-4.44, P=0.04), and 1.9-fold-higher odds of clinical pregnancy (42.6% vs. 27.1%, 95% CI: 1.03-3.87, P=0.05). Number of matured oocytes (P=0.002), normally fertilized embryos (P=0.008), 6-8 cell stage embryos (P=0.003) and blastocysts (P=0.014) were higher in cycles with stimulation >8 days. Further analysis showed that live birth rate was highest in the group of patients with normal duration stimulation group (37.3%) compared to patients with delayed stimulation (25%) and accelerated stimulation (20.8%).

CONCLUSIONS

In an IVF cycle, optimal ovarian response and pregnancy outcome is associated with stimulation duration of at least 9 days. Both accelerated and delayed follicular recruitment are indicators for suboptimal response.

A prospective study of non-invasive preimplantation genetic testing for aneuploidies (NiPGT-A) using next-generation sequencing (NGS) on spent culture media (SCM)

PURPOSE

This study was to evaluate if spent culture media (SCM) of embryos could be used as a non-invasive tool to achieve aneuploidy screening. Ploidy calls, as well as concordance rates between PGT-A results from trophectoderm (TE) and SCM, were compared. Clinical outcomes of single euploid transfers were also evaluated.

METHODS

The study was conducted from March 2017 to June 2018 in a university-based ART center. SCM of day 3 to the day(s) of TE biopsy of all biopsied blastocysts were collected for testing. PGT-A results of SCM were compared with the standard results of TE, with clinical relevance and outcomes examined.

RESULTS

NiPGT-A using SCM gave a sensitivity of 81.6%, specificity of 48.3%, positive predictive value of 82.6%, and negative predictive value of 46.7% in ploidy calling. The concordance rates for autosomes and sex determination were 62.1% and 82.4%, respectively. There were 14 single embryo transfer cycles of euploids as determined by TE biopsy. Clinical outcomes not only confirmed 3 false positive results from SCM but also reflected the true ploidy status of the transferred embryo in one case. If ploidy calls were dichotomized without mosaic embryos, the sensitivity and NPV would increase to 91.0% and 66.7% (p = 0.60 and p = 0.25), respectively.

CONCLUSIONS

Cell-free DNA found in SCM could provide ploidy information of an embryo as in PGT-A from its TE. Given its potential to reflect the comprehensive chromosomal profile of the whole embryo, more research based on clinical outcomes is required to determine if SCM could be a reliable selection tool in PGT-A.

Ovarian stimulation for preimplantation genetic testing

A narrative review of the management of controlled ovarian stimulation in patients undergoing preimplantation genetic testing is presented. An electronic search was performed to identify research publications that addressed ovarian stimulation and preimplantation genetic testing published until December 2017. Studies were classified in decreasing categories: randomized controlled trials, prospective controlled trials, prospective non-controlled trials, retrospective studies and experimental studies. The aim of controlled ovarian stimulation has shifted from obtaining embryos available for transfer to yielding the maximum embryos available for biopsy to increase the odds of achieving one euploid embryo available for transfer, without the distress of inducing ovarian hyperstimulation syndrome or inadequate endometrium receptivity as vitrification and deferred embryo transfer usually will be planned. The present narrative review summarizes all treatment-related variables as well as stimulation strategies after controlled ovarian stimulation that could help patients undergoing an in vitro fertilization cycle coupled with preimplantation genetic testing, including the number of oocytes needed to achieve one healthy live birth, oral contraceptive pill usage, the role of mild ovarian stimulation or random-start stimulation, the stimulation protocol and type of gonadotropin of choice, the novel progesterone protocols, agonist or dual trigger as a final oocyte maturation trigger, the accumulation of oocytes/embryos and the optimal interval before proceeding with a subsequent controlled ovarian stimulation or the optimal medication to link stimulation cycles. The discussion is being presented according to how questions are posed in clinical practice. The aim of ovarian stimulation has shifted from obtaining embryos available for transfer to yielding the maximum embryos available for biopsy to increase the odds of achieving one euploid embryo available for transfer.

Practical Considerations in Providing Preimplantation Genetic Testing for Aneuploidies (PGT-A)

Preimplantation genetic testing for aneuploidies (PGT-A) has been controversial in its application to improve reproductive success, reduce time-to-pregnancy, and serve the intention-to-treat. Nevertheless, many in vitro fertilization (IVF) units have already introduced the service for one reason or another. Given PGT-A is not a stand-alone technique but a clinical service involving several disciplines, this mini review discussed the factors that can influence success rates when PGT-A is applied and highlighted practical issues encountered by clinicians, embryology, and genetics laboratories involved in the provision of PGT-A service.

Prediction of live birth and cumulative live birth rates in freeze-all-IVF treatment of a general population

PURPOSE

To investigate the cumulative live birth (cLB) rate of one complete freeze-all-IVF cycle in a general infertile population and to investigate patient and treatment variables that predict blastocyst development and live birth (LB).

METHOD

In a retrospective observational study, the data of all IVF cycles performed between 1 February 2015 and 31 January 2016 at a single IVF centre was investigated. In the study, patient-couples were followed up for 18 months following oocyte retrieval. After exclusions, the patient and treatment variables of 1582 patient-couples who underwent treatment were included in the analyses.

RESULTS

The median time interval between the oocyte retrieval attempt and the frozen embryo transfer (FET) in which LB was achieved was 38.0 (35.0-67.0) days. The variables of freeze-all-IVF cycles with single blastocyst FET selected by multiple logistic regression to predict LB significantly were female age, infertility duration, FET number (i.e. 1st, 2nd, or ≥ 3rd FET), and blastocyst quality. In a regression adjusting for female age, the number of blastocysts transferred, and oocyte number group (1-3, 4-9, 10-15, and > 15), none of the oocyte number groups were selected to predict LB of 1st FET, significantly. While the per transfer LB rates decreased linearly from the 1st (56.5%) to the 3rd (36.4%) FET, the cLB rate increased from 47.3% after the 1st FET to 55.0% after a 3rd possible FET.

CONCLUSION

The cLB rate of one complete freeze-all-IVF cycle of a general infertile population, with 18-month follow-up, was 55.0%. In freeze-all-IVF, ovarian reserve variables were not selected by regression models to predict LB, significantly.

The POSEIDON Criteria and Its Measure of Success Through the Eyes of Clinicians and Embryologists

This article represents a viewpoint on the POSEIDON criteria by a group of clinicians and embryologists. Its primary objective is to contextualize the Poseidon criteria and their metric of success for the relevant Frontiers Research Topic "POSEIDON's Stratification of Low Prognosis Patients in ART: The WHY, the WHAT, and the HOW". "Low prognosis" relates with reduced oocyte number, which can be associated with low or sometimes a normal ovarian reserve and is aggravated by advanced female age. These aspects will ultimately affect the number of embryos generated and consequently, the cumulative live birth rate. The novel system relies on female age, ovarian reserve markers, ovarian sensitivity to exogenous gonadotropin, and the number of oocytes retrieved, which will both identify the patients with low prognosis and stratify such patients into one of four groups of women with "expected" or "unexpected" impaired ovarian response to exogenous gonadotropin stimulation. Furthermore, the POSEIDON group introduced a new measure of clinical success in ART, namely, the ability to retrieve the number of oocytes needed to obtain at least one euploid blastocyst for transfer in each patient. Using the POSEIDON criteria, the clinician can firstly identify and classify patients who have low prognosis in ART, and secondly, aim at designing an individualized treatment plan to maximize the chances of achieving the POSEIDON measure of success in each of the four low prognosis groups. The novel POSEIDON classification system is anticipated to improve counseling and management of low prognosis patients undergoing ART, with an expected positive effect on reproductive success and a reduction in the time to live birth.

Management Strategies for POSEIDON Groups 3 and 4

In the POSEIDON classification, patients belonging to groups 3 and 4 share the same common feature of a poor ovarian reserve which independently of age renders them at high risk of a poor reproductive outcome. Overall, POSEIDON groups 1-4 constitute approximately 47% of patients attending assisted reproductive technology (ART) treatment. With the increasing delay in childbearing, POSEIDON group 4 seems to increase in numbers now in some centers constituting more than 50% of the total POSEIDON population, whereas group 3 patients constitute approximately 10%. Both POSEIDON groups 3 and 4 patients require special attention as regards pre-treatment strategy, ovarian stimulation, adjuvant treatment, and ovulation trigger strategy in order to optimize the probability of having at least one euploid blastocyst for transfer. Although more evidence is needed, recent advances seem to have increased the reproductive outcomes in the poor prognosis patient. The key to success is individualization in all steps of ART treatment. Herein, we review the recent evidence for the management of POSEIDON groups 3 and 4.

Mild ovarian stimulation with letrozole plus fixed dose human menopausal gonadotropin prior to IVF/ICSI for infertile non-obese women with polycystic ovarian syndrome being pre-treated with metformin: a pilot study

BACKGROUND

Letrozole is widely employed as ovulation induction agent in women with PCOS, but its use in mild stimulation (MS) protocols for IVF is limited. Aim of the present study was to evaluate the feasibility of a MS protocol with letrozole plus hMG in non-obese PCOS women undergoing IVF after a metformin pre-treatment.

METHODS

We retrospectively evaluated the data of 125 non-obese PCOS undergoing MS with letrozole plus hMG, 150 IU as starting dose, (group 1, N = 80) compared to those undergoing a conventional IVF stimulation protocols (CS) (group 2, N = 45) prior to IVF. All patients had received metformin extended release 1200-2000 mg daily for three to six months before IVF. GnRH antagonist was administered in both groups when the leading follicles reached 14 mm.

RESULTS

Both groups were comparable for age, BMI and ovarian reserve markers. Both groups showed lower than expected AFC and AMH values as a consequence of metformin pre-treatment. Letrozole-treated patients required a significantly lower amount of gonadotropins units (p < 0.0001), and showed significantly lower day 5, day 8 and hCG day E2 levels compared to patients undergoing the CS protocol (p < 0.0001, p < 0.0001 and p = 0.001 respectively). The oocyte yield, in terms of total (6, IQR 3, vs 6, IQR 4 respectively,) and MII oocytes (5, IQR 3, vs 5, IQR 3, respectively) number, did not differ among groups; the number of total (3, IQR 2, vs 3, IQR 1 respectively) and good quality embryos (2, IQR1 vs 2, IQR 1,5 respectively) obtained was comparable as well in the two groups. The number of fresh transfers was significantly higher in group 1 compared to group 2 (80% vs 60%, p = 0.016). A trend for higher cumulative clinical pregnancy rate was found in women undergoing MS compared to CS (42.5%vs 24,4%, p = 0.044), but the study was not powered to detect this difference.

CONCLUSIONS

The present study suggests that the use of letrozole as adjuvant treatment to MS protocols for IVF may be an effective alternative to CS protocols for non-obese PCOS patients pre-treated with metformin, as it provides comparable IVF outcome without requiring high FSH dose, and avoiding supraphysiological estradiol levels.

PCOS and pregnancy: a review of available therapies to improve the outcome of pregnancy in women with polycystic ovary syndrome

INTRODUCTION

Polycystic ovary syndrome (PCOS) is a common cause of female infertility affecting multiple aspects of a women's health.

AREAS COVERED

The aim of this review is to summarize the existing evidence on the treatment of PCOS patients and to examine the actual available therapies to overcome the problem of infertility and improve the outcome of pregnancy. We analyse different treatment strategies such as lifestyle modification, bariatric surgery, insulin sensitizing agents, inositol, clomiphene citrate (CC), aromatase inhibitors, gonadotrophins, laparoscopic ovarian drilling, and assisted reproductive techniques (ART).

EXPERT COMMENTARY

Lifestyle modification is the best initial management for obese PCOS patients seeking pregnancy and insulin sensitizing agents seem to have an important role in treating insulin resistance. Up to now, CC maintains a central role in the induction of ovulation and it has been confirmed as the first-line treatment; the use of gonadotrophins is considered the second-line in CC resistant patients; laparoscopic ovarian drilling is an alternative to gonadotrophins in patients who need laparoscopy for another reason. However, in anovulatory patients, ART represents the only possible alternative to obtain pregnancy. Larger and well-designed studies are needed to clarify the best way to improve the outcome of pregnancy in PCOS women.

The myths surrounding mild stimulation in vitro fertilization (IVF)

So-called mild controlled ovarian hyperstimulation (mCOH) has in recent years increased in popularity, claiming to be safer and more patient-friendly, while also improving in vitro fertilization (IVF) outcomes. We here challenge the International Society for Mild Approaches in Assisted Reproduction (ISMAAR) definition of mild stimulation, and especially address four fundamental issues, where our review found conventional COH (cCOH) advantageous over mCOH. They are: prevalence of severe ovarian hyperstimulation syndrome (OHSS), oocyte/embryo quality, pregnancy/live birth rates, and cost. We conclude that an objective review of the literature does not support the routine utilization of mCOH in assisted reproduction.