Gonadotrophin-releasing hormone agonist protocols for pituitary suppression in assisted reproduction

Impact of pre-treatment in GnRH-antagonist cycles triggered with GnRH agonist on reproductive outcomes

OBJECTIVE

Pre-treatment (PT) therapies in IVF are known to be used as pre-stimulation modality to improve cycle outcomes. This study aims to assess whether PT in GnRH antagonist cycles triggered with GnRH-agonist impact oocyte maturation response.

METHODS

Data were retrospectively collected for patients who underwent GnRH antagonist cycle with agonist triggering with and without PT. The patients were allocated to groups according to their PT status. The primary outcome evaluated was suboptimal maturation response. Suboptimal maturation to trigger was defined as no oocyte upon retrieval when adequate response was expected.

RESULTS

The study population included 196 patients who underwent GnRH antagonist cycle with agonist triggering. The study group included 69 patients who received PT. The control group included 127 patients with no PT. In univariate analysis, the PT group significantly displayed suboptimal response compared to the controls (p = 0.008). All the patients in the study group with suboptimal response (with or without hCG re-triggering) were treated with GnRH-agonist as PT. Basal and pre-trigger LH values were significantly lower in the study group compared to controls (p < 0.001). Multivariate regression analysis revealed that PT with GnRH agonist was a significant predictor for suboptimal response.

CONCLUSIONS

Pre-treatment, and particularly the use of GnRH-agonist as PT in antagonist cycles triggered with agonist, increases the risk of suboptimal response to GnRH-agonist trigger. This might be explained by prolonged pituitary suppression, which lasts beyond the PT cessation.

Transcriptomic signature of luteinized cumulus cells of oocytes developing to live birth after women received intracytoplasmic sperm injection

OBJECTIVE

To compare the transcriptome of human cumulus cells (CCs) from oocytes with different outcomes (pregnancy yes/no, live birth [LB] yes/no), to identify noninvasive biomarkers for oocyte selection as well as new therapeutic targets to increase LB rates from assisted reproductive technologies (ART).

DESIGN

Retrospective observational study.

SETTINGS

This study was conducted at a University Hospital in Switzerland.

PATIENTS

Subfertile couples undergoing controlled ovarian superstimulation and intracytoplasmic sperm injection with subsequent unbiopsied embryo transfer below the female age of 43 years.

INTERVENTION(S)

RNA sequencing of CCs from oocytes results in a pregnancy, no pregnancy, LB, or no LB.

MAIN OUTCOME MEASURES

Differential gene expression (DEG) between CCs of oocytes results in "no pregnancy" vs. "pregnancy" and "pregnancy only" vs. "live birth."

RESULTS

Although RNA sequencing did not reveal DEGs when comparing the transcriptomic profiles of the groups "no pregnancy" with "pregnancy," we identified 139 DEGs by comparing "pregnancy only" with "live birth," of which 28 belonged to clusters relevant to successful ART outcomes (i.e., CTGF, SERPINE2, PCK1, HHIP, HS3ST, and BIRC5). A functional enrichment analysis revealed that the transcriptome of CCs associated with LB depicts pathways of extracellular matrix, inflammatory cascades leading to ovulation, cell patterning, proliferation, and differentiation, and silencing pathways leading to apoptosis.

CONCLUSION

We identified a CCs transcriptomic profile associated with LB after embryo transfer that, after further validation, could serve to predict successful ART outcomes. The definition of relevant pathways of CCs related to oocyte competency contributes to a broader understanding of the cumulus oocyte complex and helps identify further therapeutic targets for improving ART success.

A reappraisal of ovarian stimulation strategies used in assisted reproductive technology

Ovarian stimulation is a fundamental step in assisted reproductive technology (ART) with the intention of inducing ovarian follicle development prior to timed intercourse or intra-uterine insemination and facilitating the retrieval of multiple oocytes during a single in vitro fertilization (IVF) cycle. The basis of ovarian stimulation includes the administration of exogenous gonadotropins, with or without pre-treatment with oral hormonal therapy. Gonadotropin-releasing hormone agonist or antagonist is given in addition to the gonadotropins to prevent a premature rise of endogenous luteinizing hormone that would in turn lead to premature ovulation. With the advancement in technology, various stimulation protocols have been devised to cater for different patient needs. However, ovarian hyperstimulation syndrome and its serious complications may occur following ovarian stimulation. It is also evident that suboptimal ovarian stimulation strategies may have a negative impact on oogenesis, embryo quality, endometrial receptivity, and reproductive outcomes over recent years. This review describes the various forms of pre-treatment for ovarian stimulation and stimulation protocols, and aims to provide clinicians with the latest available evidence.

Effect of serum progesterone levels on hCG trigger day on pregnancy outcomes in GnRH antagonist cycles

OBJECTIVE

The present study analyzed the effect of hCG trigger day progesterone (P) levels on the live birth rate (LBR) in the gonadotropin-releasing hormone (GnRH) antagonist protocol.

MATERIALS AND METHODS

This study was a single-center retrospective study. In vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) cycles performed from January 2017 to December 2020 were included in the analysis. This study included people with a normal ovarian response to fresh embryo transfer of GnRH antagonist protocols. All cycles were divided into 2 groups by P level on the day of human chorionic gonadotropin (hCG) trigger, P<1.0 ng/ml and P≥1.0 ng/ml. The primary outcome measure was LBR.

RESULT

A total of 867 cycles with P<1.0 ng/ml and 362 cycles with P≥1.0 ng/ml were included in the analysis. The clinical pregnancy rate (CPR) was higher in the P<1.0 ng/ml group than the P≥1.0 ng/ml group (44.9% vs. 37.6%, P=0.02). The early spontaneous abortion rate was comparable between the groups (14.4% vs. 14.7%, P=0.93). For live birth, the rate for the P<1.0 ng/ml group was 35.3%, which was significantly higher than the 29.0% in the P≥1.0 ng/ml group (P=0.03). After binary logistic regression analysis, the P level on the hCG trigger day (adjusted odds ratio=0.74, 95% CI=0.55-0.99, P=0.04) was an independent risk factor for LBR. For the P level on the hCG trigger day, the LBR was lower in the P≥1.0 ng/ml group compared to the P<1.0 ng/ml group.

CONCLUSION

For normal ovarian response patients using the GnRH antagonist protocol, serum P≥1.0 ng/ml on the hCG trigger day resulted in a lower LBR than the P<1.0 ng/ml group. When P≥1.0 ng/ml, whole embryo freezing may be considered.

Arthroscopic Hip Surgery versus Conservative Therapy on Femoroacetabular Impingement Syndrome: A Meta-Analysis of RCTs

To determine the outcome and differences between arthroscopic hip surgery and conservative therapy in patients suffering from femoroacetabular impingement syndrome, we searched articles from PubMed, Embase, Cochrane, Web of Science and Clinicaltrials.gov using a Boolean search algorithm. Only randomized controlled trials comparing arthroscopic hip surgery and conservative therapy were included in this meta‐analysis of femoroacetabular impingement syndrome management. Two authors determined eligibility, extracted the needed data and assessed the risk of bias of eligible studies independently. Then we meta‐analyzed three articles to assess pooled estimate size (ES) and 95% confidence interval for Hip Outcome Score of activities of daily living (HOS ADL subscale), Hip Outcome Score sport (HOS sports subscale) and International Hip Outcome Tool (iHOT‐33) analyses were performed by using STATA version 14.0 MP (STATA, College Station, TX, USA) with the principal summary measures are mean between group difference, sample size, and standard deviation. We collected 52 articles in total after removing duplicates and screened by titles and abstracts. A total of three RCTs were included finally. There was definite evidence of additional benefit of arthroscopic hip surgery against conservative therapy in the field of improving quality of life (three trials, 575 participants, ES = 2.109, 95% CI: 1.373 to 2.845, I² = 42.8%, P = 0.000) and activity of daily living (two trials, 262 participants, ES = 9.220, 95% CI: 5.931 to 12.508, I² = 16.5%, P = 0.000). However, no significant difference could be seen in sports function improvement (two trials, ES = 7.562, 95% CI: −2.957 to 18.082, I² = 60.1%, P = 0.159). In conclusion, this meta‐analysis suggests that arthroscopic hip surgery provided essential benefit compared with conservative therapy in improving activity of daily living and quality of life.

No significant long-term complications from inadvertent exposure to gonadotropin-releasing hormone agonist during early pregnancy in mothers and offspring: a retrospective analysis

BACKGROUND

Administration of gonadotropin-releasing hormone agonist (GnRH-a) in the luteal phase is commonly used for pituitary suppression during in vitro fertilisation (IVF). There is an ineluctable risk of inadvertent exposure of spontaneous pregnancy to GnRH-a. However, little is known about the pregnancy complications and repregnancy outcomes of the affected women and the neurodevelopmental outcomes of the GnRH-a-exposed children.

METHODS

Retrospective analysis was used to determine obstetric and repregnancy outcomes after natural conception in 114 women who naturally conceived while receiving GnRH-a during their early pregnancy over the past 17 years. The GnRH-a-exposed children were evaluated to determine their neonatal characteristics and long-term neurodevelopmental outcomes. The outcomes were compared to those of relevant age-matched control groups.

RESULTS

Sixty-five women had 66 live births. The neonatal health outcomes and the incidence of maternal complications were similar in the GnRH-a-exposed and control groups. Thirty-one GnRH-a-exposed children, aged 2-8 years, were available for investigation of neurodevelopment. Except for one case of autism spectrum disorder, the full-scale intelligence quotient score was within the normal range and similar to that of the control group. Most mothers with successful pregnancies and about one-third of the women who had spontaneous abortions were subsequently able to conceive naturally again. IVF is recommended for repregnancy in women who have experienced ectopic pregnancies.

CONCLUSIONS

Accidental exposure to GnRH-a in early pregnancy might be safe. Reproductive treatment suggestions for repregnancy should be made with consideration of the outcomes of the previously GnRH-a-exposed spontaneous pregnancy.

Controlled ovarian hyperstimulation for poor ovarian responders undergoing in vitro fertilisation/intracytoplasmic sperm injection: a protocol for systematic review and Bayesian network meta-analysis

INTRODUCTION

Controlled ovarian hyperstimulation (COH) is the routine regimen used to generate a sufficient number of follicles during in vitro fertilisation (IVF) or intracytoplasmic sperm injection (ICSI) treatment. Poor ovarian response is a challenge encountered by many clinicians during COH and poor ovarian responders (PORs) usually have higher follicle stimulating hormone levels, lower levels of anti-Mullerian hormone and few oocytes retrieved, which have been attributed mainly to advanced maternal age and poor follicle reserve or other reasons that could impair ovarian response during ovarian stimulation. Over the last few decades, researchers have proposed a series of strategies and ovarian stimulation protocols to improve pregnancy outcomes in patients with POR during their IVF/ICSI treatment. However, clinical decisions regarding COH protocols in PORs during IVF/ICSI treatment remain controversial. Traditional pairwise meta-analysis only allows the direct comparison of two protocols in COH for patients with POR. However, many of these COH protocols have not been compared directly in randomised controlled trials (RCTs). Thus, we aim to use network meta-analysis (NMA) to assess the clinical effectiveness and safety of COH protocols and to generate treatment rankings of these COH protocols for the most clinically important and commonly reported outcomes events.

METHODS AND ANALYSIS

The PubMed, Embase, Cochrane Library, Web of Science, SinoMed, CNKI, WanFang database and Chongqing VIP information databases will be searched for all RCTs of COH for POR women during IVF/ICSI from inception to 31 March 2020. Primary outcomes will include live birth rate and number of oocytes retrieved. Secondary outcomes will include ongoing pregnancy rate, clinical pregnancy rate, miscarriage rate, ovarian hyperstimulation syndrome rate, multiple pregnancy rate and cycle cancellation rate. Pairwise meta-analysis and Bayesian NMA will be conducted for each outcome. Subgroup analysis, meta-regression, and sensitivity analysis will be performed to assess the robustness of the findings. The generation of NMA plots and subsequent results will be performed by using R V.4.0.1. The assessment of confidence in network estimates will use the Confidence in Network Meta-Analysis)web application (see https://cinema.ispm.unibe.ch/).

ETHICS AND DISSEMINATION

This review does not require ethics approval and the results of the NMA will be submitted to a peer-review journal.

A flexible short protocol in women with poor ovarian response over 40 years old

BACKGROUND

Ovarian responsiveness to controlled ovarian stimulation is essential for a successful clinical outcome in assisted reproductive technology (ART) cycles. We aimed to find a suitable new ovulation stimulation protocol for poor ovarian response (POR) patients over 40 years old.

METHODS

A retrospective analysis of 488 ART cycles was evaluated from January 2015 to June 2019. Comparisons were made between the flexible short protocol (FSP), routine short protocol and mild stimulation protocol.

RESULTS

Compared with the routine short protocol, the FSP delayed the gonadotropin start time and reduced the total gonadotropin dose per stimulation cycle. At the same time, compared with the mild stimulation protocol, the FSP improved oocyte quality and embryo quality and improved embryo implantation potential after transfer. Furthermore, the use of the FSP reduced the probability of premature ovulation, as it inhibited the premature luteinizing hormone (LH) surge to a certain extent.

CONCLUSIONS

The FSP yielded better outcomes than other protocols for patients with POR over 40 years old in our study. However, further prospective studies are needed to provide more substantial evidence and to determine whether the FSP can be successful for both patients over 40 years group and younger POR patients.

Fixed Gonadotropin-Releasing Hormone Antagonist Protocol Versus Flexible Progestin-Primed Ovarian Stimulation Protocol in Patients With Asynchronous Follicular Development During Controlled Ovulation Stimulation: A Retrospective Study

Protocols utilizing gonadotropin-releasing hormone (GnRH) antagonists have emerged as mainstream procedures for ovarian stimulation; however, GnRH increases the risk for periodic cancellation of embryos. Therefore, this study aimed to compare the pregnancy outcomes of a fixed GnRH antagonist protocol and a flexible progestin-primed ovarian stimulation (fPPOS) protocol in patients with asynchronous follicular development during controlled ovulation stimulation and to explore the feasibility of converting patients undergoing a fixed GnRH antagonist protocol to an fPPOS protocol. This was the first retrospective study exploring the fPPOS protocol in patients with asynchronous follicular development, and it was conducted in a public reproductive medicine center from January to December 2020. We included infertile women. All participants were scheduled to undergo administration of a GnRH antagonist on the fifth day of controlled ovulation stimulation. The study group included 129 women who were converted from the fixed GnRH antagonist protocol to the fPPOS protocol for their asynchronous follicular development, while the antagonist group consisted of 258 women (ratio 1:2) who proceeded with a fixed GnRH antagonist protocol. On the second or third day of the menstrual period, 100-300 IU/day gonadotropin injections were administered. For patients who were converted to the fPPOS protocol, medroxyprogesterone acetate tablets at 10 mg/day were started on the fifth day of stimulation or when only one leading follicle reached 14 mm and the other follicles were ≤10 mm in diameter, whichever came first. The rates of embryo implantation, clinical pregnancy, and early pregnancy loss were obtained. The number of oocytes retrieved and the number of high-quality embryos in the antagonist group were significantly higher than those in the fPPOS group (P = 0.039 and P = 0.025, respectively). No significant differences in the rates of embryo implantation, clinical pregnancy, and early pregnancy loss were observed between the two groups. Our study found that in patients who were scheduled for administration of GnRH antagonists but presented with asynchronous follicular development on the fifth stimulation day, it was feasible to switch to the fPPOS protocol.

Maternal serum concentration of anti-Müllerian hormone is a better predictor than basal follicle stimulating hormone of successful blastocysts development during IVF treatment

Background

The conditions of diminished ovarian reserve and primary ovarian insufficiency, characterized by poor fertility outcomes, currently comprise a major challenge in reproductive medicine, particularly in vitro fertilization. Currently in the IVF industry, blastocyst developmental success rate per treatment is routinely overlooked when a live birth results from treatment. Limited data are available on this significant and actionable variable of blastocyst development optimization, which contributes to improvement of treatment success Women with elevated basal FSH concentration are reported to still achieve reasonable pregnancy rates, although only a few studies report correlations with blastocysts development. Diagnostic values of AMH/basal FSH concentrations can be useful for determining the optimal stimulation protocol as well as identification of individuals who will not benefit from IVF due to poor prognosis. The objective of this study is to identify actionable clinical and culture characteristics of IVF treatment that influence blastocyst developmental rate, with the goal of acquiring optimal success.

Methods and findings

A retrospective observational study was performed, based on 106 women undergoing IVF, regardless of prognosis, over a six-month period from January 1, 2015 to June 31, 2015. Rate of high-quality blastocyst production, which can be used for embryo transfer or vitrification, per normally fertilized oocyte, was evaluated. Treatment was determined successful when outcome was ≥ 40% high-quality blastocysts. The data were initially evaluated with the Evtree algorithm, a statistical computational analysis which is inspired by natural Darwinian evolution incorporating concepts such as mutation and natural selection (see Supplementary Material). The analysis processes all variables simultaneously against the outcome, aiming to maximize discrimination of each variable to then create a “branch” of the tree which can be used as a decision in treatment. The final model results in only those variables which are significant to outcomes. Generalized linear model (GLM) employing logistic regression and survival analysis with R software was used and the final fitting of the model was determined through the use of random forest and evolutionary tree algorithms. Individuals presenting with an [AMH] of >3.15 ng/ml and a good prognosis had a lower success per treatment (n = 11, 0% success) when total gonadotropin doses were greater than 3325 IU. Individuals that presented with an [AMH] of <1.78 ng/ml and a poor prognosis exhibited a greater success per treatment (n = 11, 80% success). AMH emerged as a superior indicator of blastocyst development compared to basal FSH. The accuracy of the prediction model, our statistical analysis using decision tree, evtree methodology is 86.5% in correctly predicting outcome based on the significant variables. The likelihood that the outcome with be incorrect of the model, or the error rate is 13.5%.

Conclusions

[AMH] is a superior indicator of ovarian stimulation response and an actionable variable for stimulation dose management for optimizing blastocyst development in culture. Women whose [AMH] is ≥3.2 mg/ml, having a good prognosis, and developing >12 mature follicles result in <40% blastocysts when gonadotropin doses exceed 3325 IU per treatment. IVF treatments for poor responders that present with infertility due to diminished ovarian reserve, if managed appropriately, can produce more usable blastocyst per IVF treatment, thus increasing rate of blastocyst developmental success and ultimately increasing live birth rates. Future studies are needed to investigate the intra-follicular and the intra-cellular mechanisms that lead to the inverse relationship of blastocysts development and total gonadotropin doses in good responders in contrast to poor responders.

Reproductive outcomes after in vitro fertilization treatment in a cohort of Danish women transplanted with cryopreserved ovarian tissue

OBJECTIVE

To evaluate ovarian stimulation regimens and reproductive outcomes in a cohort of women undergoing ovarian tissue cryopreservation (OTC) and ovarian tissue transplantation (OTT).

DESIGN

Retrospective cohort study.

SETTING

University hospital and fertility clinics.

PATIENTS

Twenty-eight women undergoing OTT and in vitro fertilization (IVF) from 2012 to 2017.

INTERVENTION

OTC, OTT, and IVF.

MAIN OUTCOME MEASURES

Ovarian stimulation and IVF outcomes.

RESULTS

In total, 99 cycles were performed in 28 patients. In 19 patients responding to stimulation, a median of 3.0 cycles per patient (range: 1-14 cycles) was performed, and 2.0 mature oocytes were retrieved per cycle. The empty follicle rate was 35.9%. Eleven women achieved 15 pregnancies, of which 60% were lost during the first or second trimester, resulting in 5 of 28 women having ≥1 live births, and seven healthy children being born. In breast cancer patients (mean age at OTC: 33.0 years), the pregnancy rates (PR) and live birth rates (LBR) were 35.0% and 5.0% per embryo transfer, respectively. Patients aged ≥34.5 years at OTC all had breast cancer and did not achieve any pregnancies. For all other diagnoses (mean age at OTC: 26.6 years), PR and LBR were 50.0% and 37.5% per embryo transfer, respectively. Collectively, 39% of patients conceived at least once, and 17.9% delivered. Frozen-thawed embryo transfer (FET) resulted in more pregnancies than did fresh embryo transfer.

CONCLUSION

Our results suggest that women of advanced maternal age undergoing OTC and IVF have a poor ovarian reserve, resulting in a poor reproductive outcome. Interestingly, FET appeared to be superior to fresh transfer.

ESHRE guideline: ovarian stimulation for IVF/ICSI†

STUDY QUESTION

What is the recommended management of ovarian stimulation, based on the best available evidence in the literature?

SUMMARY ANSWER

The guideline development group formulated 84 recommendations answering 18 key questions on ovarian stimulation.

WHAT IS KNOWN ALREADY

Ovarian stimulation for IVF/ICSI has been discussed briefly in the National Institute for Health and Care Excellence guideline on fertility problems, and the Royal Australian and New Zealand College of Obstetricians and Gynaecologist has published a statement on ovarian stimulation in assisted reproduction. There are, to our knowledge, no evidence-based guidelines dedicated to the process of ovarian stimulation.

STUDY DESIGN, SIZE, DURATION

The guideline was developed according to the structured methodology for development of ESHRE guidelines. After formulation of key questions by a group of experts, literature searches and assessments were performed. Papers published up to 8 November 2018 and written in English were included. The critical outcomes for this guideline were efficacy in terms of cumulative live birth rate per started cycle or live birth rate per started cycle, as well as safety in terms of the rate of occurrence of moderate and/or severe ovarian hyperstimulation syndrome (OHSS).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Based on the collected evidence, recommendations were formulated and discussed until consensus was reached within the guideline group. A stakeholder review was organized after finalization of the draft. The final version was approved by the guideline group and the ESHRE Executive Committee.

MAIN RESULTS AND THE ROLE OF CHANCE

The guideline provides 84 recommendations: 7 recommendations on pre-stimulation management, 40 recommendations on LH suppression and gonadotrophin stimulation, 11 recommendations on monitoring during ovarian stimulation, 18 recommendations on triggering of final oocyte maturation and luteal support and 8 recommendations on the prevention of OHSS. These include 61 evidence-based recommendations—of which only 21 were formulated as strong recommendations—and 19 good practice points and 4 research-only recommendations. The guideline includes a strong recommendation for the use of either antral follicle count or anti-Müllerian hormone (instead of other ovarian reserve tests) to predict high and poor response to ovarian stimulation. The guideline also includes a strong recommendation for the use of the GnRH antagonist protocol over the GnRH agonist protocols in the general IVF/ICSI population, based on the comparable efficacy and higher safety. For predicted poor responders, GnRH antagonists and GnRH agonists are equally recommended. With regards to hormone pre-treatment and other adjuvant treatments (metformin, growth hormone (GH), testosterone, dehydroepiandrosterone, aspirin and sildenafil), the guideline group concluded that none are recommended for increasing efficacy or safety.

LIMITATIONS, REASON FOR CAUTION

Several newer interventions are not well studied yet. For most of these interventions, a recommendation against the intervention or a research-only recommendation was formulated based on insufficient evidence. Future studies may require these recommendations to be revised.

WIDER IMPLICATIONS OF THE FINDINGS

The guideline provides clinicians with clear advice on best practice in ovarian stimulation, based on the best evidence available. In addition, a list of research recommendations is provided to promote further studies in ovarian stimulation.

STUDY FUNDING/COMPETING INTEREST(S)

The guideline was developed and funded by ESHRE, covering expenses associated with the guideline meetings, with the literature searches and with the dissemination of the guideline. The guideline group members did not receive payment. F.B. reports research grant from Ferring and consulting fees from Merck, Ferring, Gedeon Richter and speaker’s fees from Merck. N.P. reports research grants from Ferring, MSD, Roche Diagnositics, Theramex and Besins Healthcare; consulting fees from MSD, Ferring and IBSA; and speaker’s fees from Ferring, MSD, Merck Serono, IBSA, Theramex, Besins Healthcare, Gedeon Richter and Roche Diagnostics. A.L.M reports research grants from Ferring, MSD, IBSA, Merck Serono, Gedeon Richter and TEVA and consulting fees from Roche, Beckman-Coulter. G.G. reports consulting fees from MSD, Ferring, Merck Serono, IBSA, Finox, Theramex, Gedeon-Richter, Glycotope, Abbott, Vitrolife, Biosilu, ReprodWissen, Obseva and PregLem and speaker’s fees from MSD, Ferring, Merck Serono, IBSA, Finox, TEVA, Gedeon Richter, Glycotope, Abbott, Vitrolife and Biosilu. E.B. reports research grants from Gedeon Richter; consulting and speaker’s fees from MSD, Ferring, Abbot, Gedeon Richter, Merck Serono, Roche Diagnostics and IBSA; and ownership interest from IVI-RMS Valencia. P.H. reports research grants from Gedeon Richter, Merck, IBSA and Ferring and speaker’s fees from MSD, IBSA, Merck and Gedeon Richter. J.U. reports speaker’s fees from IBSA and Ferring. N.M. reports research grants from MSD, Merck and IBSA; consulting fees from MSD, Merck, IBSA and Ferring and speaker’s fees from MSD, Merck, IBSA, Gedeon Richter and Theramex. M.G. reports speaker’s fees from Merck Serono, Ferring, Gedeon Richter and MSD. S.K.S. reports speaker’s fees from Merck, MSD, Ferring and Pharmasure. E.K. reports speaker’s fees from Merck Serono, Angellini Pharma and MSD. M.K. reports speaker’s fees from Ferring. T.T. reports speaker’s fees from Merck, MSD and MLD. The other authors report no conflicts of interest.

Disclaimer

This guideline represents the views of ESHRE, which were achieved after careful consideration of the scientific evidence available at the time of preparation. In the absence of scientific evidence on certain aspects, a consensus between the relevant ESHRE stakeholders has been obtained.

Adherence to these clinical practice guidelines does not guarantee a successful or specific outcome, nor does it establish a standard of care. Clinical practice guidelines do not replace the need for application of clinical judgment to each individual presentation, nor variations based on locality and facility type.

ESHRE makes no warranty, express or implied, regarding the clinical practice guidelines and specifically excludes any warranties of merchantability and fitness for a particular use or purpose. (Full disclaimer available atwww.eshre.eu/guidelines.)

^†ESHRE Pages content is not externally peer reviewed. The manuscript has been approved by the Executive Committee of ESHRE.

Effect of Switching from a Progestin-Primed Ovarian Stimulation Protocol to a Modified Ultra-Long Protocol Among Women Who Had 1 Progestin-Primed Ovarian Stimulation (PPOS) Failure Verses Those Who Had 2 PPOS Failures

BACKGROUND There is little research on whether normoresponsive patients who produced poor-quality embryos once verses those who produced poor-quality embryos twice when using a single COH protocol should change to a different controlled ovarian hyperstimulation (COH) protocol. MATERIAL AND METHODS In this retrospective study, we enrolled 108 patients with 1 PPOS failure who chose to continue receiving the progestin-primed ovarian stimulation (PPOS) protocol (n=61) versus those who decided to switch to the modified ultra-long protocol (n=47). We also enrolled 131 normoresponsive patients with 2 PPOS failures who chose to continue receiving the PPOS protocol (n=60) versus those who decided to switch to the modified ultra-long protocol (n=71) in the third cycle. RESULTS We found no significant difference in clinical outcomes of patients with 1 PPOS failure who continued using the PPOS protocol verses those who switched to the modified ultra-long protocol in the second cycle, expect for a lower cancelation rate (4.3% vs. 16.4%). However, the patients with 2 PPOS failures had significantly more good-quality embryos (0.9 vs. 0.4), more viable embryos (1.8 vs. 0.9), lower cancelation rates (18.3% vs. 53.3%), and higher pregnancy rates per aspirated cycle (26.8% vs. 10.0%) when switching to the modified ultra-long protocol compared to those who decided to continue receiving the PPOS protocol (P<0.05). Furthermore, the odds of clinical pregnancy (odds ratio [OR] 5.997, 95% confidence interval [CI] 1.476-24.361, P=0.01) were positively associated with switching to the COH protocol in the third cycle. CONCLUSIONS For normoresponsive patients with poor-quality embryos when using the PPOS protocol, switching to the modified ultra-long protocol after having 2 PPOS failures was associated with better ART outcomes.

Management Strategies for POSEIDON Group 2

Although individualization of ovarian stimulation aims at maximal efficacy and safety in assisted reproductive treatments, in its current form it is far from ideal in achieving the desired success in women with a low prognosis. This could be due a failure to identify such women who are likely to have a low prognosis with currently used prognostic characteristics. Introduction of the patient-oriented strategies encompassing individualized oocyte number (POSEIDON) concept reinforces recognizing such low prognosis groups and stratifying in accordance with important prognostic factors. The POSEIDON concept provides a practical approach to the management of these women and is a useful tool for both counseling and clinical management. In this commentary, we focus on likely management strategies for POSEIDON group 2 criteria.

Prolonged pituitary down-regulation with full-dose of gonadotropin-releasing hormone agonist in different menstrual cycles: a retrospective cohort study

Background

The efficiency of prolonged down-regulation caused by a full-dose of gonadotropin-releasing hormone agonist (GnRH-a) injected during different menstrual phases has not yet been researched. Our goal was to evaluate the effects of GnRH-a, which was used in different phases of the menstrual cycle in patients undergoing in vitro fertilization and embryo transfer.

Methods

This was a retrospective cohort study. A total of 320 patients received a prolonged pituitary down-regulated full-dose (3.75 mg) of triptorelin in the early follicular phase, and 160 patients received the same full-dose of triptorelin during the mid-luteal phase. Clinical and laboratory outcomes were compared between the two groups.

Results

The basic characteristics of the two groups were comparable. The mean number of retrieved oocytes, fertilized oocytes, cleavage oocytes and good quality embryos were comparable between the two groups. Although there was a higher antral follicle count, cyst formation rate, fertilization rate and cleavage rate in the follicular phase group, no statistically significant effects were seen on implantation rate (41.15% vs. 45.91%), clinical pregnancy rate (60.38% vs. 61.36%), ongoing pregnancy rate (57.74% vs. 57.58%), live birth rate (56.23% vs. 57.58%) or early abortion rate (2.64% vs. 3.79%) per fresh transfer cycle. Moreover, severe ovarian hyperstimulation syndrome rates at the early stage (1.89% vs. 2.27%) were low in both groups.

Conclusions

Prolonged pituitary down-regulation achieved by utilizing a full-dose of GnRH-a administrated in either phase of the menstrual cycle can have a positive effect on ongoing pregnancy rate and live-birth rate per fresh embryo transfer cycle. Ovarian cyst formation rate was higher in the follicular phase group, but this did not have any adverse impact on clinical results.

Medical or surgical treatment before embryo transfer improves outcomes in women with abnormal endometrial BCL6 expression

PURPOSE

To evaluate the effect of medical or surgical treatment prior to embryo transfer in women with elevated endometrial BCL6 expression and suspected endometriosis in a prospective, cohort study design at a university-associated infertility clinic.

METHODS

All subjects had at least 1 year of unexplained infertility (UI) and each prospectively underwent endometrial biopsy and immunostaining for the oncogene BCL6, prior to embryo transfer during an assisted reproductive technology (ART) cycle. To be included, subjects had to have an abnormal BCL6 result, defined by elevated HSCORE ≥ 1.4. Women that were pre-treated with laparoscopy or medical suppression with GnRH agonist (depot leuprolide acetate; Lupron®, Abbvie, Inc., Chicago, IL) for 2 months were compared to a group that went untreated (controls). Endpoints included implantation rate (IR), clinical pregnancy rate (CPR), and live birth rate (LBR), and as well as cycle characteristics. Miscarriage rate were also compared between treatment and control group.

RESULTS

Women in each group had similar characteristics. Those treated by medical suppression and those undergoing laparoscopy for endometriosis had a significantly higher LBR, (5/10; 50%; 95%CI 23.7 to 76.3%) and (11/21; 52.4%; 95%CI 32.4 to 71.7), respectively, compared to controls (4/54; 7.4%; 95%CI 2.9 to 17.6). An absolute benefit of 44.2% (16/31; 95%CI 24.6 to 61.2) and a number need to treat of 3 for those that received treatment (medical suppression and laparoscopy), compared to no treatment. Miscarriages were significantly more common in the control group.

CONCLUSIONS

Women with suspected endometriosis and aberrant endometrial BCL6 expression have worse reproductive outcomes following embryo transfer, including a high miscarriage rate, poor IR, and low LBR and CPR compared to cycles pre-treated with medical and surgical management.

LH Levels May Be Used as an Indicator for the Time of Antagonist Administration in GnRH Antagonist Protocols-A Proof-Of-Concept Study

Objective: To investigate whether circulating LH levels could be used as an indicator for the timing of antagonist addition in GnRH antagonist protocol. Design: Retrospective cohort study. Setting: University-based hospital. Patients: A total of 567 women stimulated with recombinant FSH monotherapy in a GnRH antagonist protocol were studied. Among them, 256 patients showed relatively low LH levels [highest LH level (LHmax) < 4 IU/L] during the entire ovarian stimulation process; 88 (Group A) and 168 patients (Group B) were stimulated without and with antagonist co-treatment, respectively. The remaining 311 patients had LHmax≥4 IU/L and were stimulated with a modified flexible antagonist protocol based on LH levels (Group C). Intervention(s): Patients in Group B and C received antagonist during ovarian stimulation, whereas patients in Group A did not. Main outcome measure: Clinical pregnancy rate and ongoing pregnancy rate. Results: The clinical and ongoing pregnancy rates were significantly higher in group A than group B (69.3 vs. 54.7%, P = 0.03 and 62.5 vs. 48.2%, P = 0.04, respectively), but the primary outcome measures did not differ between groups B and C. There were no significant differences in terms of patient demographics, LH levels, total dosage of gonadotrophin, duration of stimulation, follicular output rate between groups A and B, and between groups B and C. Also, there were no significant differences in laboratory and clinical outcomes in pairwise group comparisons. No canceled cycles due to premature ovulation was reported among the treated patients. Conclusion: LH levels may be used as an indicator for the time of antagonist addition. Patients with sustained low LH levels (LHmax<4 IU/L) during controlled ovarian stimulation (COS) might not require antagonist administration. Although further well-designed randomized controlled trials (RCTs) are needed to confirm our results, a novel treatment regimen based on LH measurements during COS might provide clinicians new insights about when to start antagonist administration in the GnRH antagonist protocol.

Delayed Start Protocol with Gonadotropin-releasing Hormone Antagonist in Poor Responders Undergoing In Vitro Fertilization: A Randomized, Double-blinded, Clinical Trial

Objectives

We sought to determine the effects of the delayed start protocol with gonadotropin-releasing hormone (GnRH) antagonists in poor responders undergoing in vitro fertilization (IVF).

Methods

This randomized clinical trial was conducted during a 15-month period from April 2014 to July 2015 in clinics in Shiraz, Iran. A total of 42 poor responders with primary infertility were randomly assigned to the controlled ovarian stimulation group utilizing the delayed start protocol (n = 21) or the traditional group (n = 21) using GnRH antagonist, Cetrotide. The primary endpoint was the number of patients undergoing oocyte pick-up, implantation, and the rate of pregnancy.

Results

The baseline characteristics of the two study groups were comparable including age, infertility duration, and body mass index. The number of follicles measuring > 13 mm in diameter (p = 0.057), retrieved oocytes (p = 0.564), mature metaphase II oocytes (p = 0.366), embryos (p = 0.709), and transferred embryos (p = 0.060) were comparable between the two groups. The number of patients undergoing oocyte pick-up (p = 0.311), the rates of implantation (p = 0.407), and pregnancy (p = 0.596) were also comparable between the two groups.

Conclusions

The delayed start protocol was not associated with better conception results or cycle outcomes in poor responders with primary infertility undergoing IVF cycles.

Assisted reproductive technology: an overview of Cochrane Reviews

BACKGROUND

As many as one in six couples will encounter problems with fertility, defined as failure to achieve a clinical pregnancy after regular intercourse for 12 months. Increasingly, couples are turning to assisted reproductive technology (ART) for help with conceiving and ultimately giving birth to a healthy live baby of their own. Fertility treatments are complex, and each ART cycle consists of several steps. If one of these steps is incorrectly applied, the stakes are high as conception may not occur. With this in mind, it is important that each step of the ART cycle is supported by good evidence from well-designed studies.

OBJECTIVES

To summarise the evidence from Cochrane systematic reviews on procedures and treatment options available to couples with subfertility undergoing assisted reproductive technology (ART) procedures.

METHODS

Published Cochrane systematic reviews of couples undergoing ART procedures (in vitro fertilisation or intracytoplasmic sperm injection) were eligible for inclusion in the overview. We also identified Cochrane reviews in preparation, for future inclusion.The primary outcome of the overview was live birth or the composite outcome live birth or ongoing pregnancy, as reported by the included reviews. Our secondary outcomes were clinical pregnancy, multiple pregnancy, miscarriage, and ovarian hyperstimulation syndrome. We excluded studies of intrauterine insemination and ovulation induction.We undertook selection of systematic reviews, data extraction, and quality assessment in duplicate. We assessed review quality by using the AMSTAR tool. We organised reviews by their relevance to specific stages in the ART cycle. We summarised their findings in the text and reported data for each outcome in 'Additional tables'.

MAIN RESULTS

We included 68 systematic reviews published in the Cochrane Library up to May 2018. All were of high quality. These reviews identified 38 interventions that were effective (n = 23) or promising (n = 15), and they identified 19 interventions that were ineffective (n = 2) or possibly ineffective (n = 17). For 15 interventions, review authors were unable to draw conclusions owing to lack of evidence.We identified an additional 11 protocols and four titles for future inclusion in this overview.

AUTHORS' CONCLUSIONS

This overview provides the most up-to-date evidence on ART cycles from systematic reviews of randomised controlled trials. Fertility treatments are costly, and the stakes are high. Using the best available evidence to optimise outcomes is best practice. Evidence from this overview could be used to develop clinical practice guidelines and protocols that can be applied in daily clinical practice to improve live birth rates and reduce rates of multiple pregnancy, cycle cancellation, and ovarian hyperstimulation syndrome.

Oral medications including clomiphene citrate or aromatase inhibitors with gonadotropins for controlled ovarian stimulation in women undergoing in vitro fertilisation

BACKGROUND

Gonadotropins are the most commonly used medications for controlled ovarian stimulation in in vitro fertilisation (IVF). However, they are expensive and invasive, and are associated with the risk of ovarian hyperstimulation syndrome (OHSS). Recent calls for more patient-friendly regimens have led to growing interest in the use of clomiphene citrate (CC) and aromatase inhibitors with or without gonadotropins to reduce the burden of hormonal injections. It is currently unknown whether regimens using CC or aromatase inhibitors such as letrozole (Ltz) are as effective as gonadotropins alone.

OBJECTIVES

To determine the effectiveness and safety of regimens including oral induction medication (such as clomiphene citrate or letrozole) versus gonadotropin-only regimens for controlled ovarian stimulation in IVF or intracytoplasmic sperm injection (ICSI) treatment.

SEARCH METHODS

We searched the following databases: Cochrane Gynaecology and Fertility Group Specialised Register (searched January 2017), the Cochrane Central Register of Controlled Trials (CENTRAL CRSO), MEDLINE (1946 to January 2017), Embase (1980 to January 2017), and reference lists of relevant articles. We also searched trials registries ClinicalTrials.gov (clinicaltrials.gov/) and the World Health Organization International Clinical Trials Registry Platform (www.who.int/trialsearch/Default.aspx). We handsearched relevant conference proceedings.

SELECTION CRITERIA

We included randomized controlled trials (RCTs). The primary outcomes were live-birth rate (LBR) and OHSS.

DATA COLLECTION AND ANALYSIS

Three review authors independently assessed trial eligibility and risk of bias. We calculated risk ratios (RR) and Peto odds ratio (OR) with 95% confidence intervals (CIs) for dichotomous outcomes and mean differences (MD) for continuous outcomes. We analyzed the general population of women undergoing IVF treatment and (as a separate analysis) women identified as poor responders. We assessed the overall quality of the evidence using the GRADE approach.

MAIN RESULTS

We included 27 studies in the updated review. Most of the new trials in the updated review included poor responders and evaluated Ltz protocols. We could perform meta-analysis with data from 22 studies including a total of 3599 participants. The quality of the evidence for different comparisons ranged from low to moderate. The main limitations in the quality of the evidence were risk of bias associated with poor reporting of study methods, and imprecision.In the general population of women undergoing IVF, it is unclear whether CC or Ltz used with or without gonadotropins compared to use of gonadotropins along with gonadotropin-releasing hormone (GnRH) agonists or antagonists resulted in a difference in live birth (RR 0.92, 95% CI 0.66 to 1.27, 4 RCTs, n = 493, I2 = 0%, low-quality evidence) or clinical pregnancy rate (RR 1.00, 95% CI 0.86 to 1.16, 12 RCTs, n = 1998, I2 = 3%, moderate-quality evidence). This means that for a typical clinic with 23% LBR using a GnRH agonist regimen, switching to CC or Ltz protocols would be expected to result in LBRs between 15% and 30%. Clomiphene citrate or Ltz protocols were associated with a reduction in the incidence of OHSS (Peto OR 0.21, 95% CI 0.11 to 0.41, 5 RCTs, n = 1067, I2 = 0%, low-quality evidence). This means that for a typical clinic with 6% prevalence of OHSS associated with a GnRH regimen, switching to CC or Ltz protocols would be expected to reduce the incidence to between 0.5% and 2.5%. We found evidence of an increase in cycle cancellation rate with the CC protocol compared to gonadotropins in GnRH protocols (RR 1.87, 95% CI 1.43 to 2.45, 9 RCTs, n = 1784, I2 = 61%, low-quality evidence). There was moderate quality evidence of a decrease in the mean number of ampoules used,) and mean number of oocytes collected with CC with or without gonadotropins compared to the gonadotropins in GnRH agonist protocols, though data were too heterogeneous to pool.Similarly, in the poor-responder population, it is unclear whether there was any difference in rates of live birth (RR 1.16, 95% CI 0.49 to 2.79, 2 RCTs, n = 357, I2 = 38%, low-quality evidence) or clinical pregnancy (RR 0.85, 95% CI 0.64 to 1.12, 8 RCTs, n = 1462, I2 = 0%, low-quality evidence) following CC or Ltz with or without gonadotropin versus gonadotropin and GnRH protocol. This means that for a typical clinic with a 5% LBR in the poor responders using a GnRH protocol, switching to CC or Ltz protocols would be expected to yield LBRs between 2% to 14%. There was low quality evidence that the CC or Ltz protocols were associated with an increase in the cycle cancellation rate (RR 1.46, 95% CI 1.18 to 1.81, 10 RCTs, n = 1601, I2 = 64%) and moderate quality evidence of a decrease in the mean number of gonadotropin ampoules used and the mean number of oocytes collected, though data were too heterogeneous to pool. The adverse effects of these protocols were poorly reported. In addition, data on foetal abnormalities following use of CC or Ltz protocols are lacking.

AUTHORS' CONCLUSIONS

We found no conclusive evidence indicating that clomiphene citrate or letrozole with or without gonadotropins differed from gonadotropins in GnRH agonist or antagonist protocols with respect to their effects on live-birth or pregnancy rates, either in the general population of women undergoing IVF treatment or in women who were poor responders. Use of clomiphene or letrozole led to a reduction in the amount of gonadotropins required and the incidence of OHSS. However, use of clomiphene citrate or letrozole may be associated with a significant increase in the incidence of cycle cancellations, as well as reductions in the mean number of oocytes retrieved in both the general IVF population and the poor responders. Larger, high-quality randomized trials are needed to reach a firm conclusion before they are adopted into routine clinical practice.

Differences in utilization of Intracytoplasmic sperm injection (ICSI) within human services (HHS) regions and metropolitan megaregions in the U.S

BACKGROUND

Anecdotal evidence suggests that US practice patterns for ART differ by geographical region. The purpose of this study was to determine whether use of ICSI differs by region and to evaluate whether these rates are correlated with differences in live birth rates.

METHODS

Public data for 2012 were obtained from the Centers for Disease Control and Prevention. Clinics with ≥100 fresh, non-donor cycles were grouped by 10 nationally recognized Department of Health & Human Services regions and 11 metropolitan Megaregions and were compared for use of ICSI, frequency of male factor infertility, and live birth rate in women <35 years.

RESULTS

There were 274 clinics in the Health & Human Services regions and 247 in the Megaregions. ICSI utilization rates in Health & Human Services groups ranged between 52.5-78.2% (P < 0.0001). Live birth rates per cycle in women <35 years differed (34.1-47.6%; P < 0.0001) but did not correlate with rates of ICSI (R² = 0.2096; P = 0.18) per cycle. For Megaregions, rates of ICSI per cycle differed (63.4%-93.5%, P < 0.0001) as did live birth rates per cycle for women <35 (36.0%-59.0%, P = 0.001) but there was only minimal correlation between them (R² = 0.5347; P = 0.01). Highest rates of ICSI occurred in Front Range (93.5%) and Gulf Coast (83.1%) Megaregions. Lowest rates occurred in the Northeast (63.4%) and Florida (64.8%) Megaregions. Male factor infertility rates did not differ across regions.

CONCLUSIONS

ICSI utilization and live birth rates per cycle for each clinic group were significantly different across geographical regions of the U.S. However, higher ICSI utilization rate was not associated with higher rates of male factor infertility nor were they strongly correlated with higher live birth rates per cycle. Studies are needed to understand factors that may influence ICSI overutilization in the U.S.

Mild Versus Conventional Ovarian Stimulation for Poor Responders Undergoing IVF/ICSI

BACKGROUND/AIM

Mild stimulation protocols have been implemented to be offered to subfertile patients who respond poorly to ovarian stimulation. We aimed to compare the efficacy of mild versus conventional gonadotropin-releasing hormone (GnRH)-agonist and antagonist protocols in poor responders undergoing in vitro fertilization/intra-cytoplasmic sperm injection (IVF/ICSI) cycles.

PATIENTS AND METHODS

A total of 58 poorly-responding patients were divided into two groups: mild group (n=33), receiving clomiphene citrate 100 mg and 0.25 mg of cetrorelix with 150 IU of gonadotrophins daily; conventional group (n=25), undergoing the long GnRH-agonist or -antagonist protocols. The primary outcome was the number of cumulus oocyte complexes (COCs) retrieved.

RESULTS

A lower number of COCs [median (range)=1 (0-4) vs. 3 (0-8.4), p<0.001] was retrieved in the mild stimulation compared to the conventional group. Secondary outcomes favored the conventional group, whereas live birth (9.1% vs. 12%), clinical pregnancy (12.1% vs. 20%) and miscarriage rate (40% vs. 40%) were similar in the two groups.

CONCLUSION

Mild ovarian stimulation is inferior to conventional regimes when applied to poor responders undergoing IVF/ICSI, in terms of the numbers of retrieved COCs.

Systematic Prediction of the Impacts of Mutations in MicroRNA Seed Sequences

MicroRNAs are a class of small non-coding RNAs that are involved in many important biological processes and the dysfunction of microRNA has been associated with many diseases. The seed region of a microRNA is of crucial importance to its target recognition. Mutations in microRNA seed regions may disrupt the binding of microRNAs to their original target genes and make them bind to new target genes. Here we use a knowledge-based computational method to systematically predict the functional effects of all the possible single nucleotide mutations in human microRNA seed regions. The result provides a comprehensive reference for the functional assessment of the impacts of possible natural and artificial single nucleotide mutations in microRNA seed regions.

Interventions for the prevention of OHSS in ART cycles: an overview of Cochrane reviews

BACKGROUND

Ovarian hyperstimulation syndrome (OHSS) in assisted reproductive technology (ART) cycles is a treatment-induced disease that has an estimated prevalence of 20% to 33% in its mild form and 3% to 8% in its moderate or severe form. These numbers might even be higher for high-risk women such as those with polycystic ovaries or a high oocyte yield from ovum pickup.

OBJECTIVES

The objective of this overview is to identify and summarise all evidence from Cochrane systematic reviews on interventions for prevention or treatment of moderate, severe and overall OHSS in couples with subfertility who are undergoing ART cycles.

METHODS

Published Cochrane systematic reviews reporting on moderate, severe or overall OHSS as an outcome in ART cycles were eligible for inclusion in this overview. We also identified Cochrane submitted protocols and title registrations for future inclusion in the overview. The evidence is current to 12 December 2016. We identified reviews, protocols and titles by searching the Cochrane Gynaecology and Fertility Group Database of Systematic Reviews and Archie (the Cochrane information management system) in July 2016 on the effectiveness of interventions for outcomes of moderate, severe and overall OHSS. We undertook in duplicate selection of systematic reviews, data extraction and quality assessment. We used the AMSTAR (Assessing the Methodological Quality of Systematic Reviews) tool to assess the quality of included reviews, and we used GRADE methods to assess the quality of the evidence for each outcome. We summarised the characteristics of included reviews in the text and in additional tables.

MAIN RESULTS

We included a total of 27 reviews in this overview. The reviews were generally of high quality according to AMSTAR ratings, and included studies provided evidence that ranged from very low to high in quality. Ten reviews had not been updated in the past three years. Seven reviews described interventions that provided a beneficial effect in reducing OHSS rates, and we categorised one additional review as 'promising'. Of the effective interventions, all except one had no detrimental effect on pregnancy outcomes. Evidence of at least moderate quality indicates that clinicians should consider the following interventions in ART cycles to reduce OHSS rates.• Metformin treatment before and during an ART cycle for women with PCOS (moderate-quality evidence).• Gonadotrophin-releasing hormone (GnRH) antagonist protocol in ART cycles (moderate-quality evidence).• GnRH agonist (GnRHa) trigger in donor oocyte or 'freeze-all' programmes (moderate-quality evidence). Evidence of low or very low quality suggests that clinicians should consider the following interventions in ART cycles to reduce OHSS rates.• Clomiphene citrate for controlled ovarian stimulation in ART cycles (low-quality evidence).• Cabergoline around the time of human chorionic gonadotrophin (hCG) administration or oocyte pickup in ART cycles (low-quality evidence).• Intravenous fluids (plasma expanders) around the time of hCG administration or oocyte pickup in ART cycles (very low-quality evidence).• Progesterone for luteal phase support in ART cycles (low-quality evidence).• Coasting (withholding gonadotrophins) - a promising intervention that needs to be researched further for reduction of OHSS.On the basis of this overview, we must conclude that evidence is currently insufficient to support the widespread practice of embryo cryopreservation.

AUTHORS' CONCLUSIONS

Currently, 27 reviews in the Cochrane Library were conducted to report on or to try to report on OHSS in ART cycles. We identified four review protocols but no new registered titles that can potentially be included in this overview in the future. This overview provides the most up-to-date evidence on prevention of OHSS in ART cycles from all currently published Cochrane reviews on ART. Clinicians can use the evidence summarised in this overview to choose the best treatment regimen for individual patients - a regimen that not only reduces the chance of developing OHSS but does not compromise other outcomes such as pregnancy or live birth rate. Review results, however, are limited by the lack of recent primary studies or updated reviews. Furthermore, this overview can be used by policymakers in developing local and regional protocols or guidelines and can reveal knowledge gaps for future research.