How should we report outcomes in reproductive medicine?

Impact of BMI on fertility in an otherwise healthy population: a systematic review and meta-analysis

BACKGROUND

An increased body mass index (BMI) can lead to subfertility; however, current literature fails to exclude the effect of other confounding medical conditions, raising questions regarding the direct link between increased BMI and fertility outcomes.

OBJECTIVES

To conduct a systematic review and meta-analysis to elucidate the effects of increased BMI on fertility outcomes in females with no other comorbidities.

SEARCH STRATEGY

A comprehensive search was conducted using EMBASE, MEDLINE and the Cochrane library from January 2000 until July 2023.

DATA COLLECTION AND ANALYSIS

Two authors independently conducted data extraction and assessed study quality. Odds ratio (OR) (dichotomous data), standardised mean difference (SMD) (continuous data) and 95% CIs were calculated.

MAIN RESULTS

Nine eligible studies were identified: one natural conception and eight assisted reproductive technology (ART). Aggregated data revealed women with BMI ≥25 were less likely to attain clinical pregnancy (OR 0.76, 95% CIs 0.62 to 0.93, p=0.007), with BMI ≥30 associated with a further decreased likelihood of clinical pregnancy (OR 0.61, 95% CIs 0.39 to 0.98, p=0.04). Women with raised BMI required longer duration of stimulation (SMD=0.08, 95% CIs 0.00 to 0.16, p=0.04) and obtained reduced oocytes (SMD=-0.11, 95% CIs -0.18 to -0.04, p=0.002).

CONCLUSIONS

These data demonstrate an adverse impact of being overweight/obese on ART outcomes in women with no other diagnosed medical comorbidities and highlight the distinct lack of data concerning the effects of isolated obesity on natural conception. Infertility represents an enormous burden for couples and society; it is essential to identify and tackle modifiable risk factors to improve chances of conception.

PROSPERO REGISTRATION NUMBER

CRD42022293631.

Follitropin Alpha versus Follitropin Beta in IVF/ICSI Cycle: A Retrospective Cohort Study

Purpose

The purpose of this study was to compare the efficacy of Follitropin alpha (Gonal-F) and Follitropin beta (Puregon) on cumulative live birth rate (CLBR), defined as the percentage of the number of patients who delivered for the first time in a single ovarian stimulation cycle and the number of patients in all oocyte retrieval cycles.

Methods

A retrospective cohort study including 2864 infertile patients who underwent ovarian stimulation with Puregon (group A, n=1313) and Gonal-F (group B, n=1551) was conducted between July 2015 and June 2021 at a university-affiliated reproductive medicine center. Reduce potential confounding factors between groups, propensity scores and multivariable logistic regression analyses were estimated to obtain unbiased estimates of outcomes. The primary outcome was the difference in CLBR between the two groups.

Results

Each group identified 1160 individuals after propensity score matching (PSM). Baseline characteristics were similar between groups after PSM. The total gonadotrophin (Gn) dose (2400 vs 2325), p=0.038) and cost of Gn usage (5327.9¥ vs 7547.2¥, p<0.001) between the Puregon and Gonal-F groups were statistically significant. Nevertheless, the pregnancy outcomes between the two groups were comparable after fresh embryo transfer and subsequent frozen-thawed embryo transfer. Additionally, there was also no difference observed in the primary outcome of CLBR (52.8% vs 55.7%, p=0.169). Multivariable regression analysis revealed that the type of Gn was not associated with CLBR (p = 0.912).

Conclusion

Gonal-F may be a reasonable option for infertile patients who are hesitant to receive more Gn dosage injections. Furthermore, Puregon can eliminate unneeded anxiety and expenses while also administering more flexibility. Taken together, these findings could well be utilized in everyday clinical practice to better inform patients when deciding on an ovarian stimulation strategy.

Live birth rate after oocyte donation in females diagnosed with turner syndrome: a systematic review and meta-analysis

BACKGROUND

An enduring challenge for women diagnosed with Turner syndrome (TS) is infertility. Oocyte donation (OD) offers a chance of pregnancy for these patients. However, current data on pregnancy outcomes are inadequate. Hence, this systematic review aims to explore the clinical outcomes of OD in patients with TS.

METHODS

A systematic search was conducted in PubMed, Web of Sciences, Scopus, and Embase for relevant papers from 1 January 1990 to 30 November 2023. Our primary research objective is to determine the live birth rate among women with TS who have undergone in vitro fertilization (IVF) using OD for fertility purposes. Specifically, we aim to calculate the pooled live birth rates per patient and per embryo transfer (ET) cycle. For secondary outcomes, we have analyzed the rates of clinical pregnancy achievement per ET cycle and the incidence of gestational hypertensive complications per clinical pregnancy. Prevalence meta-analyses were performed using STATA 18.0 by utilizing a random-effects model and calculating the pooled rates of each outcome using a 95% confidence interval (CI).

RESULTS

A total of 14 studies encompassing 417 patients were systematically reviewed. Except for one prospective clinical trial and one prospective cohort study, all other 12 studies had a retrospective cohort design. Our meta-analysis has yielded a pooled live birth rate per patient of 40% (95% CI: 29-51%; 14 studies included) and a pooled live birth rate per ET cycle of 17% (95% CI: 13-20%; 13 studies included). Also, the pooled clinical pregnancy achievement rate per ET cycle was estimated at 31% (95% CI: 25-36%; 12 studies included). Moreover, the pooled rate of pregnancy-induced hypertensive disorders per clinical pregnancy was estimated at 12% (95% CI: 1-31%; 8 studies included). No publication bias was found across all analyses.

CONCLUSIONS

This study demonstrated promising pregnancy outcomes for OD in patients with TS. Further studies are essential to address not only the preferred techniques, but also the psychological, ethical, and societal implications of these complex procedures for these vulnerable populations.

TRIAL REGISTRATION

This systematic review was registered in the International Prospective Register of Systematic Reviews (PROSPERO) under the registration code CRD42023494273.

Endometrial compaction to predict pregnancy outcomes in patients undergoing assisted reproductive technologies: a systematic review and meta-analysis

STUDY QUESTION

Does endometrial compaction (EC) help predict pregnancy outcomes in those undergoing ART?

SUMMARY ANSWER

EC is associated with a significantly higher clinical pregnancy rate (CPR) and ongoing pregnancy rate (OPR), but this does not translate to live birth rate (LBR).

WHAT IS KNOWN ALREADY

EC describes the progesterone-induced decrease in endometrial thickness, which may be observed following the end of the proliferative phase, prior to embryo transfer. EC is proposed as a non-invasive tool to help predict pregnancy outcome in those undergoing ART, however, published data is conflicting.

STUDY DESIGN SIZE DURATION

A literature search was carried out by two independent authors using PubMed, Cochrane Library, MEDLINE, Embase, Science Direct, Scopus, and Web of Science from inception of databases to May 2023. All peer-reviewed studies reporting EC and pregnancy outcomes in patients undergoing IVF/ICSI treatment were included.

PARTICIPANTS/MATERIALS SETTING METHODS

The primary outcome is LBR. Secondary outcomes included other pregnancy metrics (positive pregnancy test (PPT), CPR, OPR, miscarriage rate (MR)) and rate of EC. Comparative meta-analyses comparing EC and no EC were conducted for each outcome using a random-effects model if I 2 > 50%. The Mantel-Haenszel method was applied for pooling dichotomous data. Results are presented as odds ratios (OR) with 95% CI.

MAIN RESULTS AND THE ROLE OF CHANCE

Out of 4030 screened articles, 21 cohort studies were included in the final analysis (n = 27 857). No significant difference was found between LBR in the EC versus the no EC group (OR 0.95; 95% CI 0.87-1.04). OPR was significantly higher within the EC group (OR 1.61; 95% CI 1.09-2.38), particularly when EC ≥ 15% compared to no EC (OR 3.52; 95% CI 2.36-5.23). CPR was inconsistently defined across the studies, affecting the findings. When defined as a viable intrauterine pregnancy <12 weeks, the EC group had significantly higher CPR than no EC (OR 1.83; 95% CI 1.15-2.92). No significant differences were found between EC and no EC for PPT (OR 1.54; 95% CI 0.97-2.45) or MR (OR 1.06; 95% CI 0.92-1.56). The pooled weighted incidence of EC across all studies was 32% (95% CI 26-38%).

LIMITATIONS REASONS FOR CAUTION

Heterogeneity due to differences between reported pregnancy outcomes, definition of EC, method of ultrasound, and cycle protocol may account for the lack of translation between CPR/OPR and LBR findings; thus, all pooled data should be viewed with an element of caution.

WIDER IMPLICATIONS OF THE FINDINGS

In this dataset, the significantly higher CPR/OPR with EC does not translate to LBR. Although stratification of women according to EC cannot currently be recommended in clinical practice, a large and well-designed clinical trial to rigorously assess EC as a non-invasive predictor of a successful pregnancy is warranted. We urge for consistent outcome reporting to be mandated for ART trials so that data can be pooled, compared, and concluded on.

STUDY FUNDING/COMPETING INTERESTS

H.A. was supported by the Hewitt Fertility Centre. S.G.P. and J.W. were supported by the Liverpool University Hospital NHS Foundation Trust. D.K.H. was supported by a Wellbeing of Women project grant (RG2137) and MRC clinical research training fellowship (MR/V007238/1). N.T. was supported by the National Institute for Health and Care Research. D.K.H. had received honoraria for consultancy for Theramex and has received payment for presentations from Theramex and Gideon Richter. The remaining authors have no conflicts of interest to report.

REGISTRATION NUMBER

PROSPERO CRD42022378464.

IVF versus IUI with ovarian stimulation for unexplained infertility: a collaborative individual participant data meta-analysis

BACKGROUND

IVF and IUI with ovarian stimulation (IUI-OS) are widely used in managing unexplained infertility. IUI-OS is generally considered first-line therapy, followed by IVF only if IUI-OS is unsuccessful after several attempts. However, there is a growing interest in using IVF for immediate treatment because it is believed to lead to higher live birth rates and shorter time to pregnancy.

OBJECTIVE AND RATIONALE

Randomized controlled trials (RCTs) comparing IVF versus IUI-OS had varied study designs and findings. Some RCTs used complex algorithms to combine IVF and IUI-OS, while others had unequal follow-up time between arms or compared treatments on a per-cycle basis, which introduced biases. Comparing cumulative live birth rates of IVF and IUI-OS within a consistent time frame is necessary for a fair head-to-head comparison. Previous meta-analyses of RCTs did not consider the time it takes to achieve pregnancy, which is not possible using aggregate data. Individual participant data meta-analysis (IPD-MA) allows standardization of follow-up time in different trials and time-to-event analysis methods. We performed this IPD-MA to investigate if IVF increases cumulative live birth rate considering the time leading to pregnancy and reduces multiple pregnancy rate compared to IUI-OS in couples with unexplained infertility.

SEARCH METHODS

We searched MEDLINE, EMBASE, CENTRAL, PsycINFO, CINAHL, and the Cochrane Gynaecology and Fertility Group Specialised Register to identify RCTs that completed data collection before June 2021. A search update was carried out in January 2023. RCTs that compared IVF/ICSI to IUI-OS in couples with unexplained infertility were eligible. We invited author groups of eligible studies to join the IPD-MA and share the deidentified IPD of their RCTs. IPD were checked and standardized before synthesis. The quality of evidence was assessed using the Risk of Bias 2 tool.

OUTCOMES

Of eight potentially eligible RCTs, two were considered awaiting classification. In the other six trials, four shared IPD of 934 women, of which 550 were allocated to IVF and 383 to IUI-OS. Because the interventions were unable to blind, two RCTs had a high risk of bias, one had some concerns, and one had a low risk of bias. Considering the time to pregnancy leading to live birth, the cumulative live birth rate was not significantly higher in IVF compared to that in IUI-OS (4 RCTs, 908 women, 50.3% versus 43.2%, hazard ratio 1.19, 95% CI 0.81-1.74, I2 = 42.4%). For the safety primary outcome, the rate of multiple pregnancy was not significantly lower in IVF than IUI-OS (3 RCTs, 890 women, 3.8% versus 5.2% of all couples randomized, odds ratio 0.78, 95% CI 0.41-1.50, I2 = 0.0%).

WIDER IMPLICATIONS

There is no robust evidence that in couples with unexplained infertility IVF achieves pregnancy leading to live birth faster than IUI-OS. IVF and IUI-OS are both viable options in terms of effectiveness and safety for managing unexplained infertility. The associated costs of interventions and the preference of couples need to be weighed in clinical decision-making.

Preimplantation genetic testing for aneuploidy: helpful but not a first choice

PURPOSE

This retrospective cohort study aimed to assess and compare the outcomes between cumulative live birth of patients with and without PGT-A and also between prior unsuccessful IVF cycles and PGT-A cycles among patients who experienced IVF but without live birth delivery, and to clarify the effective usage of PGT-A as an in vitro fertilization (IVF) add-on.

METHODS

A total of 2113 females undergoing IVF with at least one blastocyst were reviewed. Patients in the PGT-A and non-PGT-A groups were further categorized into first-time IVF and prior unsuccessful IVF groups (previous IVF experience but without live birth delivery).

RESULTS

In the PGT-A group, there were additional oocyte retrieval cycles, fewer transfer cycles per patient, higher clinical pregnancy rates per embryo transfer, and lower miscarriage rates per clinical pregnancy as compared to the non-PGT-A group, all showing significant differences. However, the first-time IVF group with PGT-A had a significantly longer duration from the first oocyte retrieval to the first live birth delivery (LBD) and a significantly lower LBD rate per patient than the non-PGT-A group. The cumulative probability for a first LBD with PGT-A was inferior in the first-time IVF group for women < 35 years, marginally superior in the prior unsuccessful IVF group of women aged 38-40 years, and similar for other groups.

CONCLUSION

PGT-A should not be recommended to all patients; however, if the first IVF treatment failed, PGT-A may reduce the patient's burden regardless of age.

The Pathway of Female Couples in a Fertility Clinic

OBJECTIVE

 The present study aims to describe the main characteristics of female couples resorting to a fertility clinic, to understand whether these patients have clear previous plans concerning procreation and how they end up completing their family planning, and to briefly describe the main outcomes of the recepción de ovocitos de pareja (ROPA, in the Spanish acronym: in English, reception of partner's oocytes) method.

METHODS

 This is a descriptive retrospective study of the pathway and outcomes of female couples in a fertility clinic during a 2-year period.

RESULTS

 A total of 129 couples were treated. Only one third of the couples had no condition potentially affecting fertility or advanced age. Most couples were decided to undergo artificial insemination or in vitro fertilization and the majority kept their plans, as opposed to 38% of the couples who decided to the ROPA method (lesbian shared in vitro fertilization) who changed plans. Live birth rates per treatment (including frozen embryo transfers) for artificial insemination, 58% for in vitro fertilization, 80% for treatments with donated oocytes or embryos, and 79% for ROPA. Four in five couples achieved live births.

CONCLUSION

 The present study highlights the importance of a thorough medical workup in same-sex couples resorting to assisted reproduction. Despite the higher-than-expected rates of fertility disorders, the outcomes were good. Most couples end up in a single parented method. Furthermore, the results of the ROPA method are reassuring.

Preimplantation genetic testing for aneuploidy: are we examining the correct outcomes?

Questions continue to be raised regarding the benefit of genetic assessment of embryos prior to transfer in IVF, specifically with regards to preimplantation genetic testing for aneuploidy (PGT-A). To evaluate and quantify these concerns, we appraised the most recent (2012-2019) randomized controlled trials on the topic. Only two of these six studies listed cumulative live birth rates per started cycle, with both eliciting a statistically non-significant result. This article describes the concern that a focus on results from the first embryo transfer compared to cumulative outcomes falsely construes PGT-A as having superior outcomes, whilst its true benefit is not confirmed, and it cannot actually improve the true pregnancy outcome of an embryo pool.

Treatment Strategies for Unexplained Infertility

Unexplained infertility is a common diagnosis among couples with infertility. Pragmatic treatment options in these couples are directed at trying to improve chances to conceive, and consequently intrauterine insemination (IUI) with ovarian stimulation and in vitro fertilization (IVF) are standard clinical practice, while expectant management remains an important alternative. While evidence on IVF or IUI with ovarian stimulation versus expectant management was inconclusive, these interventions seem more effective in couples with a poor prognosis of natural conception. Strategies such as strict cancellation criteria and single-embryo transfer aim to reduce multiple pregnancies without compromising cumulative live birth. We propose a prognosis-based approach to manage couples with unexplained infertility so as to expose less couples to unnecessary interventions and less mothers and children to the potential adverse effects of ovarian stimulation or laboratory procedures.

Efficacy and safety of recombinant human follicle-stimulating hormone in patients undergoing in vitro fertilization-embryo transfer

To compare the ovarian responses after administration of two recombinant follicle-stimulating hormone (r-FSH) preparations under gonadotropin-releasing hormone (GnRH) analogue downregulation, we conducted a phase 3, randomized, multicenter, assessor-blind, active-controlled, parallel group study. The primary outcome was the number of oocytes retrieved. The secondary outcomes included total dose and duration of r-FSH administered, oocyte quality, blood estradiol levels, follicular development, fertilization rates, implantation rates, and pregnancy rates (biochemical, clinical, and ongoing). A total of 451 patients with infertility were randomized to receive either Follitrope™ Prefilled Syringe or Gonal-F® Pen for ovarian stimulation. The mean number of oocytes retrieved was 14.9 in the FollitropeTM Prefilled Syringe group, and 12.8 in the Gonal-F® Pen group. The 95% confidence interval in the oocyte number difference between the groups was [-0.1, 4.2], demonstrating that FollitropeTM Prefilled Syringe was not inferior to Gonal-F® Pen. The clinical pregnancy rates (FollitropeTM Prefilled Syringe vs. Gonal-F® Pen: 55.4% vs. 51.9%) and ongoing pregnancy rates (44.1% vs. 43.0%) were similar between the groups. No clinically significant adverse events were observed in either group. In summary, our study indicates that FollitropeTM Prefilled Syringe is safe and efficacious for ovarian stimulation.

Interventions for unexplained infertility: a systematic review and network meta-analysis

BACKGROUND

Clinical management for unexplained infertility includes expectant management as well as active treatments, including ovarian stimulation (OS), intrauterine insemination (IUI), OS-IUI,  and in vitro fertilisation (IVF) with or without intracytoplasmic sperm injection (ICSI).Existing systematic reviews have conducted head-to-head comparisons of these interventions using pairwise meta-analyses. As this approach allows only the comparison of two interventions at a time and is contingent on the availability of appropriate primary evaluative studies, it is difficult to identify the best intervention in terms of effectiveness and safety. Network meta-analysis compares multiple treatments simultaneously by using both direct and indirect evidence and provides a hierarchy of these treatments, which can potentially better inform clinical decision-making.

OBJECTIVES

To evaluate the effectiveness and safety of different approaches to clinical management (expectant management, OS, IUI, OS-IUI, and IVF/ICSI) in couples with unexplained infertility.

SEARCH METHODS

We performed a systematic review and network meta-analysis of relevant randomised controlled trials (RCTs). We searched electronic databases including the Cochrane Gynaecology and Fertility Group Specialised Register of Controlled Trials, the Cochrane Central Register of Studies Online, MEDLINE, Embase, PsycINFO and CINAHL, up to 6 September 2018, as well as reference lists, to identify eligible studies. We also searched trial registers for ongoing trials.

SELECTION CRITERIA

We included RCTs comparing at least two of the following clinical management options in couples with unexplained infertility: expectant management, OS, IUI, OS-IUI, and IVF (or combined with ICSI).

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles and abstracts identified by the search strategy. We obtained the full texts of potentially eligible studies to assess eligibility and extracted data using standardised forms. The primary effectiveness outcome was a composite of cumulative live birth or ongoing pregnancy, and the primary safety outcome was multiple pregnancy. We performed a network meta-analysis within a random-effects multi-variate meta-analysis model. We presented treatment effects by using odds ratios (ORs) and 95% confidence intervals (CIs). For the network meta-analysis, we used Confidence in Network Meta-analysis (CINeMA) to evaluate the overall certainty of evidence.

MAIN RESULTS

We included 27 RCTs (4349 couples) in this systematic review and 24 RCTs (3983 couples) in a subsequent network meta-analysis. Overall, the certainty of evidence was low to moderate: the main limitations were imprecision and/or heterogeneity.Ten RCTs including 2725 couples reported on live birth. Evidence of differences between OS, IUI, OS-IUI, or IVF/ICSI versus expectant management was insufficient (OR 1.01, 95% CI 0.51 to 1.98; low-certainty evidence; OR 1.21, 95% CI 0.61 to 2.43; low-certainty evidence; OR 1.61, 95% CI 0.88 to 2.94; low-certainty evidence; OR 1.88, 95 CI 0.81 to 4.38; low-certainty evidence). This suggests that if the chance of live birth following expectant management is assumed to be 17%, the chance following OS, IUI, OS-IUI, and IVF would be 9% to 28%, 11% to 33%, 15% to 37%, and 14% to 47%, respectively. When only including couples with poor prognosis of natural conception (3 trials, 725 couples) we found OS-IUI and IVF/ICSI increased live birth rate compared to expectant management (OR 4.48, 95% CI 2.00 to 10.1; moderate-certainty evidence; OR 4.99, 95 CI 2.07 to 12.04; moderate-certainty evidence), while there was insufficient evidence of a difference between IVF/ICSI and OS-IUI (OR 1.11, 95% CI 0.78 to 1.60; low-certainty evidence).Eleven RCTs including 2564 couples reported on multiple pregnancy. Compared to expectant management/IUI, OS (OR 3.07, 95% CI 1.00 to 9.41; low-certainty evidence) and OS-IUI (OR 3.34 95% CI 1.09 to 10.29; moderate-certainty evidence) increased the odds of multiple pregnancy, and there was insufficient evidence of a difference between IVF/ICSI and expectant management/IUI (OR 2.66, 95% CI 0.68 to 10.43; low-certainty evidence). These findings suggest that if the chance of multiple pregnancy following expectant management or IUI is assumed to be 0.6%, the chance following OS, OS-IUI, and IVF/ICSI would be 0.6% to 5.0%, 0.6% to 5.4%, and 0.4% to 5.5%, respectively.Trial results show insufficient evidence of a difference between IVF/ICSI and OS-IUI for moderate/severe ovarian hyperstimulation syndrome (OHSS) (OR 2.50, 95% CI 0.92 to 6.76; 5 studies; 985 women; moderate-certainty evidence). This suggests that if the chance of moderate/severe OHSS following OS-IUI is assumed to be 1.1%, the chance following IVF/ICSI would be between 1.0% and 7.2%.

AUTHORS' CONCLUSIONS

There is insufficient evidence of differences in live birth between expectant management and the other four interventions (OS, IUI, OS-IUI, and IVF/ICSI). Compared to expectant management/IUI, OS may increase the odds of multiple pregnancy, and OS-IUI probably increases the odds of multiple pregnancy. Evidence on differences between IVF/ICSI and expectant management for multiple pregnancy is insufficient, as is evidence of a difference for moderate or severe OHSS between IVF/ICSI and OS-IUI.