Cumulative live birth rates following a 'freeze-all' strategy: a population-based study

Study on the influence of syphilis on the outcome of frozen-thawed embryo transfer in infertility patients

Objective

In this study, the effect of in vitro Fertilization-Embryo Transfer (IVF-ET) on the clinical outcome of patients with syphilis infertility during resuscitation cycle.

Methods

A retrospective single-center method was adopted. This study included 4430 pairs of infertile patients who underwent syphilis detection. The influence of the syphilis freeze-thaw embryos transplantation outcome was studied in the patients with infertility by comparing the general clinical characteristics of patients (age, years of infertility, body mass index (BMI), basal follicle stimulating hormone (FSH), serum basal estradiol (Estradiol, E2), transplanted intimal thickness, the number of embryos transferred) and the clinical pregnancy (biochemical pregnancy rate, clinical pregnancy rate, implantation rate, live birth rate and abortion rate).

Results

Firstly, in the clinical outcome of one frozen-thawed embryos transfer, the live birth rate of the woman's syphilis-infected group was lower than that of the uninfected group (71.3 % vs. 50.0 %), while the abortion rate was higher than that of the uninfected group (7.8 % vs. 26.7 %), and there was a statistical difference (P < 0.05), and there was no statistical difference in other indicators between other groups (P > 0.05). Secondly, in the clinical outcome of two frozen-thawed embryos transfers, the biochemical pregnancy rate (61.3 % vs. 28.6 %) and clinical pregnancy rate (42.9 % vs. 14.3 %) of the group which was infected with syphilis alone were lower than those of the uninfected group (P < 0.05), and other indicators among the other groups showed no statistical difference (P > 0.05). Thirdly, in the clinical outcomes of frozen-thawed embryos transfer three times or more, there was no significant difference in the clinical indicators between the syphilis infertility patients and the non-infected infertility patients (P > 0.05).

Conclusion

When the syphilis infertility patients and the non-infected infertile patients underwent IVF-ET treatment for the first time, the live birth rate and abortion rate of the syphilis group were significantly different (P < 0.05). In the outcome of two transplants, the biochemical pregnancy rate and clinical Pregnancy rates were significantly reduced so patients with syphilis infertility who undergo IVF-ET should be informed about the risk of adverse clinical outcomes.

The cumulative live birth rates of 18 593 women with progestin-primed ovarian stimulation-related protocols and frozen-thawed transfer cycles

STUDY QUESTION

What are the odds of achieving pregnancy when adopting progestin-primed ovarian stimulation (PPOS)-related protocols combined with repetitive frozen-thawed transfer (FET) cycles in patients with different clinical characteristics?

SUMMARY ANSWER

The cumulative live birth rates (CLBRs) of women undergoing different PPOS-related protocols can be significantly and consistently enhanced within six FET cycles when the female age is <40 years (or even <45 years) and when >5 oocytes are retrieved, regardless of antral follicle count (AFC).

WHAT IS KNOWN ALREADY

There have been numerous studies on the live birth rate of the first FET cycle in patients with PPOS-related protocols. These studies have focused mainly on comparing pregnancy outcomes with those of other stimulation protocols. However, owing to the unique features of the PPOS-related strategy, such as its flexible timing of oocyte retrieval and repeated transfer of frozen embryos, studies using the CLBR as an overall indicator of success and investigating which types of patients would benefit from this protocol are lacking.

STUDY DESIGN SIZE DURATION

This retrospective cohort study included 18 593 women who underwent PPOS-related protocols (dydrogesterone + hMG, medroxyprogesterone acetate + hMG, micronized progesterone + hMG treatment, and luteal-phase ovarian stimulation protocol) from 1 March 2011 to 31 September 2022 in our centre.

PARTICIPANTS/MATERIALS SETTING METHODS

The population was categorized by female age, number of oocytes retrieved, and AFC in the analysis of CLBR within six FET cycles. The age groups (Groups 1-5, respectively) were <30, 30-34, 35-39, 40-44, and ≥45 years. The number of oocytes retrieved was grouped as 1-5, 6-10, 11-15, 16-20, and >20. AFC was grouped as <5, 5-10, 11-15, and >15. The Kaplan-Meier analysis (optimistic method), which hypothesized that patients who did not continue treatment had the same chance of achieving a live birth as those who continued, and the competing risk method (conservative method) which hypothesized they had no chance of achieving a live birth, were applied. In further analyses, the Cox model and Fine-Gray model were adopted: the former corresponds to the optimistic scenario, and the latter corresponds to the pessimistic scenario.

MAIN RESULTS AND THE ROLE OF CHANCE

CLBR had a declining trend with female age over six FET cycles (Groups 1-5, respectively: optimistic: 96.9%, 96.6%, 91.4%, 67.3%, and 11.7%; conservative: 87.3%, 85.0%, 74.0%, 41.3%, and 7.5%), requiring more FET cycles to achieve a success rate of at least 50% (Groups 1-5, respectively: optimistic: 2, 2, 2, 4, and >6 cycles; conservative: 2, 2, 2, >,6 and >6 cycles). CLBR showed an increasing trend with the number of oocytes retrieved (Groups 1-5, respectively: optimistic: 93.8%, 94.3%, 95.8%, 96.0%, and 95.6%; conservative: 66.2%, 78.3%, 85.6%, 88.9%, and 91.0%). All groups needed the same number of FET cycles to achieve a success rate of at least 50% (Groups 1-5, respectively: optimistic: 2, 2, 2, 2, and 2 cycles; conservative: 2, 2, 2, 2, and 2 cycles). Furthermore, the CLBR within six FET cycles had an increasing trend with AFC number (Groups 1-4, respectively: optimistic: 89.2%, 94.8%, 95.9%, and 96.3%; conservative: 67.4%, 78.2%, 83.9%, and 88.1%), with all four groups achieving a success rate of at least 50% by the second FET cycle.

LIMITATIONS REASONS FOR CAUTION

The current research is limited by its retrospective design and single-centre nature, which may restrict the generalizability of our findings.

WIDER IMPLICATIONS OF THE FINDINGS

This work describes two models (the Kaplan-Meier analysis and the competing risk method) to evaluate the clinical outcome of patients using PPOS-related protocols, which are especially useful for patients of advanced age or those with diminished ovarian reserve. Our findings encourage patients below 45 years old, especially younger than 40 years, and patients with lower AFCs and fewer retrieved oocytes to try this new protocol. Moreover, this study demonstrates the degree of improvement in the CLBR within six FET cycles for patients with different clinical characteristics, providing a valuable point of reference to determine whether to continue ART after a transfer failure.

STUDY FUNDING/COMPETING INTERESTS

The study was supported by grants from the National Natural Science Foundation of China (82071603 to L.W., 82001502 to Y.L.). There are no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

ESHRE Add-ons working group, Lundin K, Bentzen JG, Bozdag G, Ebner T, Harper J, Le Clef N, Moffett A, Norcross S, Polyzos NP, Rautakallio-Hokkanen S, Sfontouris I, Sermon K, Vermeulen N, Pinborg A. Good practice recommendations on add-ons in reproductive medicine†

STUDY QUESTION

Which add-ons are safe and effective to be used in ART treatment?

SUMMARY ANSWER

Forty-two recommendations were formulated on the use of add-ons in the diagnosis of fertility problems, the IVF laboratory and clinical management of IVF treatment.

WHAT IS KNOWN ALREADY

The innovative nature of ART combined with the extremely high motivation of the patients has opened the door to the wide application of what has become known as 'add-ons' in reproductive medicine. These supplementary options are available to patients in addition to standard fertility procedures, typically incurring an additional cost. A diverse array of supplementary options is made available, encompassing tests, drugs, equipment, complementary or alternative therapies, laboratory procedures, and surgical interventions. These options share the common aim of stating to enhance pregnancy or live birth rates, mitigate the risk of miscarriage, or expedite the time to achieving pregnancy.

STUDY DESIGN, SIZE, DURATION

ESHRE aimed to develop clinically relevant and evidence-based recommendations focusing on the safety and efficacy of add-ons currently used in fertility procedures in order to improve the quality of care for patients with infertility.

PARTICIPANTS/MATERIALS, SETTING, METHODS

ESHRE appointed a European multidisciplinary working group consisting of practising clinicians, embryologists, and researchers who have demonstrated leadership and expertise in the care and research of infertility. Patient representatives were included in the working group. To ensure that the guidelines are evidence-based, the literature identified from a systematic search was reviewed and critically appraised. In the absence of any clear scientific evidence, recommendations were based on the professional experience and consensus of the working group. The guidelines are thus based on the best available evidence and expert agreement. Prior to publication, the guidelines were reviewed by 46 independent international reviewers. A total of 272 comments were received and incorporated where relevant.

MAIN RESULTS AND THE ROLE OF CHANCE

The multidisciplinary working group formulated 42 recommendations in three sections; diagnosis and diagnostic tests, laboratory tests and interventions, and clinical management.

LIMITATIONS, REASONS FOR CAUTION

Of the 42 recommendations, none could be based on high-quality evidence and only four could be based on moderate-quality evidence, implicating that 95% of the recommendations are supported only by low-quality randomized controlled trials, observational data, professional experience, or consensus of the development group.

WIDER IMPLICATIONS OF THE FINDINGS

These guidelines offer valuable direction for healthcare professionals who are responsible for the care of patients undergoing ART treatment for infertility. Their purpose is to promote safe and effective ART treatment, enabling patients to make informed decisions based on realistic expectations. The guidelines aim to ensure that patients are fully informed about the various treatment options available to them and the likelihood of any additional treatment or test to improve the chance of achieving a live birth.

STUDY FUNDING/COMPETING INTEREST(S)

All costs relating to the development process were covered from ESHRE funds. There was no external funding of the development process or manuscript production. K.L. reports speakers fees from Merck and was part of a research study by Vitrolife (unpaid). T.E. reports consulting fees from Gynemed, speakers fees from Gynemed and is part of the scientific advisory board of Hamilton Thorne. N.P.P. reports grants from Merck Serono, Ferring Pharmaceutical, Theramex, Gedeon Richter, Organon, Roche, IBSA and Besins Healthcare, speakers fees from Merck Serono, Ferring Pharmaceutical, Theramex, Gedeon Richter, Organon, Roche, IBSA and Besins Healthcare. S.R.H. declares being managing director of Fertility Europe, a not-for-profit organization receiving financial support from ESHRE. I.S. is a scientific advisor for and has stock options from Alife Health, is co-founder of IVFvision LTD (unpaid) and received speakers' fee from the 2023 ART Young Leader Prestige workshop in China. A.P. reports grants from Gedeon Richter, Ferring Pharmaceuticals and Merck A/S, consulting fees from Preglem, Novo Nordisk, Ferring Pharmaceuticals, Gedeon Richter, Cryos and Merck A/S, speakers fees from Gedeon Richter, Ferring Pharmaceuticals, Merck A/S, Theramex and Organon, travel fees from Gedeon Richter. The other authors disclosed no conflicts of interest.

DISCLAIMER

This Good Practice Recommendations (GPRs) document represents the views of ESHRE, which are the result of consensus between the relevant ESHRE stakeholders and are based on the scientific evidence available at the time of preparation.ESHRE GPRs should be used for information and educational purposes. They should not be interpreted as setting a standard of care or bedeemedinclusive of all proper methods of care, or be exclusive of other methods of care reasonably directed to obtaining the same results.Theydo not replace the need for application of clinical judgement to each individual presentation, or variations based on locality and facility type.Furthermore, ESHRE GPRs do not constitute or imply the endorsement, or favouring, of any of the included technologies by ESHRE.

Highly Purified Human Menopausal Gonadotropin (HP-hMG) Versus Recombinant Follicle-Stimulating Hormone (rFSH) for Controlled Ovarian Stimulation in US Predicted High-Responder Patients: A Cost-Comparison Analysis

OBJECTIVES

Infertility imposes considerable clinical and economic burden, and the high costs of fertility care are a major barrier to payers. This study assessed the cost differences of highly purified human menopausal gonadotropin (HP-hMG) versus recombinant follicle stimulating hormone (rFSH) for controlled ovarian stimulation (COS) protocols in predicted high-responders from the US payer perspective.

METHODS

A discrete event simulation model was built to perform a cost-comparison analysis of HP-hMG versus rFSH in a cohort of predicted high-responders undergoing up to three embryo transfer cycles, informed by efficacy data from the MEGASET-HR trial. The model considered an event-based treatment pathway and transition probabilities were derived from MEGASET-HR. A variable time horizon was employed, and deterministic and probabilistic sensitivity analyses conducted.

RESULTS

Subjects undergoing COS with HP-hMG and rFSH demonstrated comparable live birth rates following three in vitro fertilization (IVF) cycles, with 161 live births with HP-hMG and 152 live births with rFSH, per 310 high-responders. The total cost saving per live birth in subjects receiving HP-hMG versus rFSH was US$3024. These cost savings were largely driven by the need for fewer embryo transfers to achieve similar efficacy outcomes and a reduced rate of ovarian hyperstimulation syndrome. Following deterministic sensitivity analysis, HP-hMG remained cost saving in all baseline parameter variations. No parameters led to rFSH providing cost savings when compared with HP-hMG.

CONCLUSION

Comparable clinical outcomes can be achieved at a lower cost when using HP-hMG versus rFSH based COS protocols in a cohort of predicted high-responders. Such cost savings may reduce the economic burden infertility currently presents to US healthcare providers and those seeking fertility care.

Which sperm parameter limits could really guide the clinical decision in assisted reproduction?

BACKGROUND

The predictive role of sperm motility and morphology was recently detected in a large sample of more than 20000 assisted reproductive technology (ART) fresh cycles. However, the complete ART procedure consisted of both fresh and frozen-embryos transfers and only a comprehensive evaluation of the entire process could really confirm if these parameters really predict the ART success. The aim of the study was to evaluate which sperm parameter could predict the success of ART.

METHODS

A retrospective, real-world data analysis was performed, enrolling all couples attending ART from 2008 to 2021, including both fresh and frozen cycles and both in vitro fertilization (IVF) and intra-cytoplasmic sperm injection (ICSI) procedures.

RESULTS

Fresh cycles success (considering live birth rate) was predicted by female age (1.04 [1.02-1.06]), injected oocytes (0.96 [0.93-0.99]), embryo number (0.79 [0.75-0.83]) and progressive sperm motility (0.98 [0.97-0.99]). On the contrary, frozen cycle outcomes were predicted only by sperm motility (0.97 [0.95-0.99]). This prediction was confirmed in IVF but not in ICSI cycles.

CONCLUSION

Both female and male parameters predicted the ART success considering the entire path. However, frozen cycle success was predicted only by progressive sperm motility in IVF cycles, suggesting that the potential amelioration of this male parameter is relevant to improve ART success. Those couples expected to obtain the highest embryos after fertilization (low female age and better semen parameters) will have more attempts with frozen cycles and thus would benefit from a potential treatment focused to improve sperm parameters.

Does the outcome of fresh embryo transfer affect the outcome of subsequent thawed embryo transfers from sibling oocytes in patients that utilized all their embryos?

The association between fresh embryo transfer (ET) outcome and the subsequent frozen-thawed (FET) cycles that follow is not clear, mainly because of incomplete embryo cohort utilization. The aim of this study was to determine if the outcome of a fresh ET affects the frozen cumulative clinical pregnancy (CP) and live birth (LB) rates resulting from the utilization of all surplus embryos from sibling oocytes. Outcome measures were the FET cumulative CP and LB rates. Multivariate logistic regression was performed for the frozen cumulative CP rate and adjusted for age, the number of oocytes, fresh ET outcome and other confounders. A total of 1313 cycles met the inclusion criteria. The FET cumulative CP and LB rates were not affected by the outcome of the fresh ET. The FET cumulative CP rate increased with the number of oocytes collected regardless of whether a pregnancy was achieved in the fresh cycle or not. In multivariate analysis, age (OR = 0.96, 95% CI 0.94-0.98), protocol (OR = 0.13, 95% CI 0.03-0.57) and the number of oocytes (OR = 1.05, 95% CI 1.02-1.07) were associated with the frozen cumulative CP rate. It is concluded that fresh ET does not impact the outcome of the vitrified-thawed embryos from the same oocyte cohort.

Real-world evidence analysis of the follicle-stimulating hormone use in male idiopathic infertility

Male idiopathic infertility remains a therapeutic challenge in the couple infertility management. In this setting, an empirical treatment with follicle-stimulating hormone (FSH) is allowed, although not recommended. Twenty-one clinical trials and four meta-analyses highlighted an overall increased pregnancy rate in case of FSH administration, but the indiscriminate FSH prescription is still unsupported by clinical evidence in idiopathic infertility. This context could represent an example in which real-world data (RWD) could add useful information. From a nationwide clinical practice survey performed in Italy, emerged the clinicians' attitude to prescribe FSH in the case of impaired semen with a significant improvement of semen parameters, identifying FSH treatment as a therapeutic card in the real-life management. Although more robust data are still needed to optimize FSH treatment in male idiopathic infertility, RWD should be included in the body of evidence considered in healthcare decision-making.

Comparison of the cumulative live birth rates after 1 in vitro fertilization cycle in women using gonadotropin-releasing hormone antagonist protocol vs. progestin-primed ovarian stimulation: a propensity score-matched study

OBJECTIVE

To determine whether gonadotropin-releasing hormone (GnRH) antagonist protocol can improve cumulative live birth rates (CLBRs) and shorten the time to live birth (TTLB) in unselected patients compared with progestin-primed ovarian stimulation (PPOS).

DESIGN

A propensity score-matched retrospective cohort study design.

SETTING

Tertiary-care academic medical center.

PATIENT(S)

A total of 6,520 women with infertility aged 20-50 years were included.

INTERVENTION(S)

Patients underwent either the GnRH antagonist protocol (n = 5,004) or PPOS (n = 1,516) on the basis of the assessment of the attending physicians. One-to-one propensity score matching was performed with a caliper of 0.02. Women who were not matched were excluded from the analyses.

MAIN OUTCOME MEASURE(S)

The CLBR of which the ongoing status had to be achieved within 22 months from the day of ovarian stimulation and TTLB.

RESULT(S)

Each group comprised 1,424 couples after propensity score matching, and the baseline demographic characteristics of the couples after matching were comparable between the 2 groups. The cycle cancellation rate was significantly lower in the GnRH antagonist group than in the PPOS group (12.9% vs. 19.6%). The implantation rate, clinical pregnancy rate, ongoing pregnancy rate, and live birth rate per transfer were comparable between the 2 groups. However, CLBRs after 1 complete IVF cycle were significantly higher in the GnRH antagonist group than in the PPOS group (36.0% vs. 32.2%; Risk ratio = 1.12; 95% confidence interval [CI], 1.01-1.24). The average TTLB was significantly shorter in the GnRH antagonist group than in the PPOS group (9.3 months vs. 12.4 months). Using the Kaplan-Meier analysis, the cumulative incidence of ongoing pregnancy leading to live birth was significantly higher in the GnRH antagonist group than in the PPOS group (85.1% vs. 66.1%, Log-rank test). A Cox proportional hazard model revealed that women who underwent the antagonist protocol were 2.32 times more likely to achieve a live birth than those who used PPOS (hazard ratio [HR] = 2.32; 95% CI, 1.91-2.83). Subgroup analysis revealed that women who used the antagonist protocol were more likely to achieve a live birth than women who used PPOS across the 3 antral follicle count (AFC) strata (AFC ≤ 5, AFC 6-15, and AFC > 15), 2 age strata (<35 and ≥35 years), and first cycle or repeated cycle. The difference was greatest among women whose AFC was ≤5 and who were aged ≥35 years, effectively becoming smaller in the group with high ovarian reserve and younger age.

CONCLUSION(S)

In unselected women undergoing IVF, the GnRH antagonist protocol was associated with a higher CLBR and a shorter TTLB compared with PPOS.

Transfer of thawed frozen embryo versus fresh embryo to improve the healthy baby rate in women undergoing IVF: the E-Freeze RCT

BACKGROUND

Freezing all embryos, followed by thawing and transferring them into the uterine cavity at a later stage (freeze-all), instead of fresh-embryo transfer may lead to improved pregnancy rates and fewer complications during in vitro fertilisation and pregnancies resulting from it.

OBJECTIVE

We aimed to evaluate if a policy of freeze-all results in a higher healthy baby rate than the current policy of transferring fresh embryos.

DESIGN

This was a pragmatic, multicentre, two-arm, parallel-group, non-blinded, randomised controlled trial.

SETTING

Eighteen in vitro fertilisation clinics across the UK participated from February 2016 to April 2019.

PARTICIPANTS

Couples undergoing their first, second or third cycle of in vitro fertilisation treatment in which the female partner was aged < 42 years.

INTERVENTIONS

If at least three good-quality embryos were present on day 3 of embryo development, couples were randomly allocated to either freeze-all (intervention) or fresh-embryo transfer (control).

OUTCOMES

The primary outcome was a healthy baby, defined as a live, singleton baby born at term, with an appropriate weight for their gestation. Secondary outcomes included ovarian hyperstimulation, live birth and clinical pregnancy rates, complications of pregnancy and childbirth, health economic outcome, and State-Trait Anxiety Inventory scores.

RESULTS

A total of 1578 couples were consented and 619 couples were randomised. Most non-randomisations were because of the non-availability of at least three good-quality embryos (n = 476). Of the couples randomised, 117 (19%) did not adhere to the allocated intervention. The rate of non-adherence was higher in the freeze-all arm, with the leading reason being patient choice. The intention-to-treat analysis showed a healthy baby rate of 20.3% in the freeze-all arm and 24.4% in the fresh-embryo transfer arm (risk ratio 0.84, 95% confidence interval 0.62 to 1.15). Similar results were obtained using complier-average causal effect analysis (risk ratio 0.77, 95% confidence interval 0.44 to 1.10), per-protocol analysis (risk ratio 0.87, 95% confidence interval 0.59 to 1.26) and as-treated analysis (risk ratio 0.91, 95% confidence interval 0.64 to 1.29). The risk of ovarian hyperstimulation was 3.6% in the freeze-all arm and 8.1% in the fresh-embryo transfer arm (risk ratio 0.44, 99% confidence interval 0.15 to 1.30). There were no statistically significant differences between the freeze-all and the fresh-embryo transfer arms in the live birth rates (28.3% vs. 34.3%; risk ratio 0.83, 99% confidence interval 0.65 to 1.06) and clinical pregnancy rates (33.9% vs. 40.1%; risk ratio 0.85, 99% confidence interval 0.65 to 1.11). There was no statistically significant difference in anxiety scores for male participants (mean difference 0.1, 99% confidence interval -2.4 to 2.6) and female participants (mean difference 0.0, 99% confidence interval -2.2 to 2.2) between the arms. The economic analysis showed that freeze-all had a low probability of being cost-effective in terms of the incremental cost per healthy baby and incremental cost per live birth.

LIMITATIONS

We were unable to reach the original planned sample size of 1086 and the rate of non-adherence to the allocated intervention was much higher than expected.

CONCLUSION

When efficacy, safety and costs are considered, freeze-all is not better than fresh-embryo transfer.

TRIAL REGISTRATION

This trial is registered as ISRCTN61225414.

FUNDING

This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 26, No. 25. See the NIHR Journals Library website for further project information.

Ovarian Stimulation in Assisted Reproductive Technology Cycles for Varied Patient Profiles: An Indian Perspective

Controlled ovarian stimulation has been an integral part of in vitro fertilisation (IVF) treatment cycles. Availability of different gonadotropins for ovarian stimulation and gonadotropin releasing hormone (GnRH) analogues for prevention of premature rise of leutinising hormone during follicular phase offer an opportunity to utilise them for a successful outcome in women with different subsets of ovarian response. Further, use of GnRH agonist as an alternative for human chorionic gonadotropin improves safety of ovarian stimulation in hyper-responders. Mild ovarian stimulation protocols have emerged as an alternative to conventional protocols in the recent years. Individualisation plays an important role in improving safety of IVF in hyper-responders while efforts continue to improve efficacy in poor responders. Some of the follicular and peri-ovulatory phase interventions may be associated with negative impact on the luteal phase and segmentalisation of the treatment with frozen embryo transfer may be an effective strategy in such a clinical scenario. This narrative review looks at the available evidence on various aspects of ovarian stimulation strategies and their consequences. In addition, it provides a concise summary of the evidence that has emerged from India on various aspects of ovarian stimulation.

Cumulative live birth rates for low-prognosis women over 5 years or 9 frozen-thawed embryo transfer cycles

Background

For heterogeneous populations of low-prognosis women, it remains unclear as to how long individuals should continue undergoing ART when attempting to have a baby, as there have been insufficient studies to date tracking the cumulative live birth rates (CLBRs) for these women over the entire course of their ART treatment, particularly over extended time periods.

Methods

This was a retrospective analysis of 17,698 women at a tertiary care academic medical center who had begun undergoing IVI/ICSI cycles using a progestin-primed ovarian stimulation (PPOS) approach between January 2013 and January 2019. Low-prognosis patients were stratified into four groups based upon POSEIDON criteria, with patients exhibiting normal or high ovarian reserves and response to stimulation (defined as AFC ≥5, > 9 oocytes retrieved) being included as controls (group 5). The CLBR within 5 years or 9 FET cycles from the ovum pick-up (OPU) day of the first cycle was the primary endpoint for this study, including all repetitive oocyte retrieval cycles and subsequent FET cycles. Optimistic and conservative approaches were used for the analysis of CLBRs and the depiction of cumulative incidence curves.

Results

Under both optimistic and conservative model analyses, normal and good responders exhibited the highest CLBR within 5 years or 9 FET cycles, followed by younger unexpected poor responders, younger expected poor responders, older unexpected poor responders, and older expected poor responders. Upward trends in CLBRs were evident across the five groups with the prolongation of time or an increase in FET cycle counts. Within the first 2 years or 3 FET cycles, the CLBRs rose rapidly, followed by more moderate increases over the following 2–3.5 years or 4–6 cycles, with expected poor responders exhibiting the most obvious improvements. All Patients reached a CLBR plateau after 3.5 years or 6 FET cycles.

Conclusions

All low-prognosis women should undergo ART treatment for a minimum of 2 years or 3 FET cycles, and exhibit better outcomes when extending ART treatment to 3.5 years or 6 FET cycles (particularly for POSEIDON groups 3 and 4), but should consider ceasing further treatment thereafter due to a lack of apparent benefit.

Use of kisspeptin to trigger oocyte maturation during in vitro fertilisation (IVF) treatment

Infertility is a major global health issue and is associated with significant psychological distress for afflicted couples. In vitro fertilisation (IVF) utilises supra-physiological doses of stimulatory hormones to induce the growth of multiple ovarian follicles to enable surgical retrieval of several oocytes for subsequent fertilisation and implantation into the maternal endometrium. The supra-physiological degree of ovarian stimulation can lead to potential risks during IVF treatment, including ovarian hyperstimulation syndrome (OHSS) and multiple pregnancy. The choice of oocyte maturation trigger, such as human chorionic gonadotrophin (hCG) or gonadotrophin releasing hormone agonist (GnRHa), can impact both the efficacy of IVF treatment with a bearing on luteal phase hormonal dynamics and thus the degree of luteal phase support required to maintain optimal pregnancy rates, as well as on safety of treatment with particular respect to the risk of OHSS. Kisspeptin regulates gonadotrophin releasing hormone (GnRH) release and is therefore a key regulator of the hypothalamo-pituitary-gonadal (HPG) axis. Kisspeptin has been shown to be requisite for the occurrence of the physiological ovulatory luteinising hormone (LH) surge. In this review, we discuss the potential use of kisspeptin as a novel trigger of oocyte maturation.

Age-specific effect of fresh versus frozen embryo transfer on fetal anomalies or intrauterine growth restriction rate

OBJECTIVE

To compare the prevalence of congenital fetal anomalies or intrauterine fetal growth restriction (IUGR) diagnosed prenatally between two in-vitro fertilization (IVF) methods-fresh embryo transfer (ET) and frozen embryo transfer (FET).

MATERIALS AND METHODS

We retrospectively reviewed medical records of patients that had conceived via IVF, and had a fetal anatomical scan performed at Taiji Clinic between 2015 and 2019. The prevalence of fetal anomalies or IUGR between both IVF methods were compared. Prevalence of congenital anomalies or IUGR by maternal age and embryo transfer type were compared by means of Chi-square analysis. Using multivariate logistic regression, we investigated factors that might be associated with higher rates of fetal anomalies or IUGR, such as parity and number of embryos transferred.

RESULTS

A total of 2441 cases were selected (ET: n = 627 and FET: n = 1814). There was non-significant difference in the prevalence of fetal anomalies or IUGR between ET and FET groups (6.4% vs. 5.5%, p = 0.39). However, among women younger than 34 years of age, prevalence of fetal anomalies or IUGR was significantly higher in ET group (4.6% vs. 9.9%, p = 0.03).

CONCLUSIONS

Our findings suggest an age-specific effect of IVF method on the rate of fetal anomalies or IUGR and may provide useful information for physicians and infertile couples to optimize their IVF treatment plans and improve birth outcomes.

Time associations between U.S. birth rates and add-Ons to IVF practice between 2005-2016

Until 2010, the National Assisted Reproductive Technology Surveillance System (NASS) report, published annually by the Center for Disease Control and Prevention (CDC), demonstrated almost constantly improving live birth rates following fresh non-donor (fnd) in vitro fertilization (IVF) cycles. Almost unnoticed by profession and public, by 2016 they, however, reached lows not seen since 1996-1997. We here attempted to understand underlying causes for this decline. This study used publicly available IVF outcome data, reported by the CDC annually under Congressional mandate, involving over 90% of U.S. IVF centers and over 95% of U.S. IVF cycles. Years 2005, 2010, 2015 and 2016 served as index years, representing respectively, 27,047, 30,425, 21,771 and 19,137 live births in fnd IVF cycles. Concomitantly, the study associated timelines for introduction of new add-ons to IVF practice with changes in outcomes of fnd IVF cycles. Median female age remained at 36.0 years during the study period and center participation was surprisingly stable, thereby confirming reasonable phenotype stability. Main outcome measures were associations of specific IVF practice changes with declines in live IVF birth rates. Time associations were observed with increased utilization of "all-freeze" cycles (embryo banking), mild ovarian stimulation protocols, preimplantation genetic testing for aneuploidy (PGT-A) and increasing utilization of elective single embryo transfer (eSET). Among all add-ons, PGT-A, likely, affected fndIVF most profoundly. Though associations cannot denote causation, they can be hypothesis-generating. Here presented time-associations are compelling, though some of observed pregnancy and live birth loss may have been compensated by increases in frozen-thawed cycles and consequential pregnancies and live births not shown here. Pregnancies in frozen-thawed cycles, however, represent additional treatment cycles, time delays and additional costs. IVF live birth rates not seen since 1996-1997, and a likely continuous downward trend in U.S. IVF outcomes, therefore, mandate a reversal of current outcome trends, whatever ultimately the causes.

Antioxidants increase blastocyst cryosurvival and viability post-vitrification

STUDY QUESTION

What is the effect of antioxidants acetyl-L-carnitine, N-acetyl-L-cysteine and α-lipoic acid (A3) in vitrification and warming solutions on mouse blastocyst development and viability?

SUMMARY ANSWER

The combination of three antioxidants in vitrification solutions resulted in mouse blastocysts with higher developmental potential in vitro and increased viability as assessed by both an outgrowth model in vitro and fetal development following uterine transfer.

WHAT IS KNOWN ALREADY

The antioxidant combination of acetyl-L-carnitine, N-acetyl-L-cysteine and α-lipoic acid present in IVF handling and embryo culture media has significant beneficial effects on mouse embryo and fetal development, especially under oxidative stress.

STUDY DESIGN, SIZE, DURATION

The study was a laboratory-based analysis of an animal model. Rapid cooling through vitrification was conducted on F1 mouse blastocysts, with antioxidants (A3) supplemented in vitrification and/or warming solutions, followed by culture and embryo transfer.

PARTICIPANTS/MATERIALS, SETTINGS, METHODS

Pronucleate oocytes were collected and cultured in groups to Day 4 blastocysts. Expanded blastocysts were vitrified and warmed in solutions with and without the A3 antioxidants and cultured for a further 24 h. Blastocyst cell number and allocation, apoptosis and histone acetylation levels were all quantified, and viability through outgrowths and transfers assessed.

MAIN RESULTS AND THE ROLE OF CHANCE

Mouse blastocysts vitrified with no antioxidants had significantly lower cell numbers (P  < 0.001) and higher apoptotic cells (P  < 0.05) compared to non-vitrified embryos. Addition of combined A3 antioxidants to the vitrification and warming solutions resulted in a significant increase in inner cell mass cell (ICM) number (P  < 0.001) and total cell number (P  < 0.01), and an increase in outgrowth area (P < 0.05), which correlated with the increased fetal weight (P < 0.05), crown rump length (P < 0.05) and limb development (P < 0.05) determined following transfer compared to embryos with no antioxidants. Furthermore, while blastocyst vitrification significantly reduced acetylation levels (P < 0.05) compared to non-vitrified embryos, the inclusion of A3 antioxidants helped to ameliorate this.

LIMITATIONS, REASONS FOR CAUTION

Embryo development was only examined in the mouse.

WIDER IMPLICATIONS OF THE FINDINGS

Results in this study demonstrate that vitrification and warming of blastocysts have significant detrimental effects on embryo histone acetylation and subsequent viability. The presence of antioxidants in the vitrification solutions helps to alleviate the negative effects of cryopreservation. Our data indicate that antioxidants need to be present in the medium at the time of exposure to increased oxidative stress associated with vitrification and that prior exposure (i.e. during culture or IVF alone) is insufficient to protect cells against cryo-induced injury. Hence, A3 antioxidants may assist in maintaining the viability of vitrified human embryos in ART through the reduction of oxidative stress.

STUDY FUNDING/COMPETING INTEREST(S)

This work was funded by a research grant from Vitrolife AB (Sweden). The authors have no conflict of interest to declare.

The freeze-all strategy after IVF: which indications?

The freeze-all strategy is gaining popularity worldwide as an alternative to the conventional fresh embryo transfer. It consists of cryopreservation of the entire embryo cohort and the embryo transfer in a subsequent cycle that takes place separately from ovarian stimulation. The freeze-all strategy was initially a 'rescue' strategy for women at high risk of ovarian hyperstimulation syndrome; however, this approach has been extended to other indications as a scheduled strategy to improve implantation rates. This assumes that ovarian stimulation can alter endometrial receptivity in fresh cycles owing to the effect of supraphysiological levels of steroids on endometrial maturation. The procedure, however, has not been associated with increased live birth rates in all infertile couples, and concerns have been raised about the occurrence of several adverse perinatal outcomes. It is, therefore, crucial to identify in which subgroups of patients a freeze-all strategy could be beneficial. The aim of this review is to summarize current scientific research in this field to highlight potential indications for this strategy and to guide clinicians in their daily practice.

Impact of elective frozen vs. fresh embryo transfer strategies on cumulative live birth: Do deleterious effects still exist in normal & hyper responders?

Background

Is freeze-all strategy effective in terms of cumulative live birth rates (CLBRs) in all patients?

Methods

This retrospective single-center study analyzed the CLBRs of 2523 patients undergoing fresh or electively frozen blastocyst transfer cycles. In 1047, cycles, the fresh embryo transfer (ET) strategy was applied for the 1^st ET, whereas electively frozen ET (e-FET) was performed in 1476 cycles. Female age ≤ 37 and blastocysts frozen via vitrification were included. The patients in each arm were further stratified into four subgroups according to the number of oocytes retrieved as follows: Group A: 1–5, group B: 6–10, group C: 11–15 and group D: 16–25 oocytes retrieved. The primary endpoint was the CLBR. The secondary endpoints were the ovarian hyperstimulation syndrome (OHSS) rate and the live birth rates (LBRs) following fresh ETs and e-FETs for the first transfers.

Result(s)

The CLBR was similar between the fresh ET and e-FET arms in group A (35/76 (46.1%) vs 29/67 (43.3%), p = 0.74) and group B (165/275 (60%) vs 216/324 (66.7%), p = 0.091), whereas significantly higher rates were detected in favor of the e-FET arm within group C (328/460 (71.3%) vs 201/348 (57.8%), p<0.001) and group D (227/348 (65.2%), vs 446/625 (71.5%), p<0.001). The OHSS rate was also found to be higher in the fresh ET arm among group C (12/348 (3.4%) vs 0/460 (0%), p<0.001) and group D (38/348 (10.9%) vs 3/625 (0.5%), p<0.001) patients than e-FET arm. Perinatal and obstetrical outcomes were nonsignificantly different between fresh and e-FET arms. However, the birth weights were significantly lower for fresh ET, 3064 versus 3201 g for singletons (p<0.001)

Conclusion

Compared with a fresh-transfer strategy, the e-FET strategy resulted in a higher CLBR among patients with >10 oocytes retrieved during stimulated cycles.

Hormone Replacement Versus Natural Cycle Protocols of Endometrial Preparation for Frozen Embryo Transfer

RESEARCH QUESTION

Endometrial preparation is one of the most important steps for ensuring frozen embryo transfer success. However, there is no clear evidence that identifies an optimal endometrial preparation protocol for frozen embryo transfer. In addition, in studies that assessed which were the optimal endometrial preparation protocols, few analyzed the stage and the number of embryos. This study compared the pregnancy outcomes and perinatal obstetric complications of patients who were transferred two cleavage-stage (day 2 or day 3) frozen embryos with the natural cycle and those with the hormone replacement therapy cycle.

DESIGN

This study was a secondary analysis of data from a multicentre randomized controlled trial designed to compare the pregnancy and perinatal outcomes after frozen versus fresh embryo transfer. In this study, a total of 908 patients who were transferred two cleavage-stage (day 2 or day 3) embryos in the original trial were analyzed. Pregnancy outcomes and perinatal obstetric complications after the natural cycle and the hormone replacement therapy cycle were compared.

RESULT

We found the endometrium in the natural group was significantly thicker than the hormone replacement therapy cycle group (p<0.01). The implantation rate (42.6% vs 37.3% p=0.049) showed a significant difference between the natural cycle group and the hormone replacement therapy cycle group. Compared to the natural cycle group, the hormone replacement therapy cycle group was associated with an increased risk of caesarean section (72.3% vs 84.5, p=0.009).

CONCLUSION

The natural cycle protocol yielded thicker endometria, a higher implantation rate and a lower risk of caesarean section than the hormone replacement therapy protocol in the transfer of two cleavage-stage frozen embryos. The natural cycle protocol was the better endometrial preparation protocol for frozen embryo transfer.

Live birth rates and perinatal outcomes when all embryos are frozen compared with conventional fresh and frozen embryo transfer: a cohort study of 337,148 in vitro fertilisation cycles

BACKGROUND

It is not known whether segmentation of an in vitro fertilisation (IVF) cycle, with freezing of all embryos prior to transfer, increases the chance of a live birth after all embryos are transferred.

METHODS

In a prospective study of UK Human Fertilisation and Embryology Authority data, we investigated the impact of segmentation, compared with initial fresh embryo followed by frozen embryo transfers, on live birth rate and perinatal outcomes. We used generalised linear models to assess the effect of segmentation in the whole cohort, with additional analyses within women who had experienced both segmentation and non-segmentation. We compared rates of live birth, low birthweight (LBW < 2.5 kg), preterm birth (< 37 weeks), macrosomia (> 4 kg), small for gestational age (SGA < 10th centile), and large for gestational age (LGA > 90th centile) for a given ovarian stimulation cycle accounting for all embryo transfers.

RESULTS

We assessed 202,968 women undergoing 337,148 ovarian stimulation cycles and 399,896 embryo transfer procedures. Live birth rates were similar in unadjusted analyses for segmented and non-segmented cycles (rate ratio 1.05, 95% CI 1.02-1.08) but lower in segmented cycles when adjusted for age, cycle number, cause of infertility, and ovarian response (rate ratio 0.80, 95% CI 0.78-0.83). Segmented cycles were associated with increased risk of macrosomia (adjusted risk ratio 1.72, 95% CI 1.55-1.92) and LGA (1.51, 1.38-1.66) but lower risk of LBW (0.71, 0.65-0.78) and SGA (0.64, 0.56-0.72). With adjustment for blastocyst/cleavage-stage embryo transfer in those with data on this (329,621 cycles), results were not notably changed. Similar results were observed comparing segmented to non-segmented within 3261 women who had both and when analyses were repeated excluding multiple embryo cycles and multiple pregnancies. When analyses were restricted to women with a single embryo transfer, the transfer of a frozen-thawed embryo in a segmented cycles was no longer associated with a lower risk of LBW (0.97, 0.71-1.33) or SGA (0.84, 0.61-1.15), but the risk of macrosomia (1.74, 1.39-2.20) and LGA (1.49, 1.20-1.86) persisted. When the analyses for perinatal outcomes were further restricted to solely frozen embryo transfers, there was no strong statistical evidence for associations.

CONCLUSIONS

Widespread application of segmentation and freezing of all embryos to unselected patient populations may be associated with lower cumulative live birth rates and should be restricted to those with a clinical indication.