IVF success corrected for drop-out: use of inverse probability weighting

Preimplantation genetic testing for aneuploidy helps to achieve a live birth with fewer transfer cycles for the blastocyst FET patients with unexplained recurrent implantation failure

PURPOSE

This retrospective cohort study aimed to investigate the value of preimplantation genetic testing for aneuploidy (PGT-A) as a screening test for patients suffering from unexplained recurrent implantation failure (RIF).

METHODS

After screening patients in one reproductive medicine center, twenty-nine, forty-nine and thirty-eight women (< 40 years old) who had suffered unexplained RIF with PGT-A, or RIF without PGT-A, or no RIF with PGT-A were included. The clinical pregnancy rate and live birth rate per transfer, the conservative and optimal cumulative clinical pregnancy rates (CCPR) and live birth rates (CLBR) after three blastocyst FETs were analyzed.

RESULTS

The live birth rate per transfer was significantly higher in the RIF + PGT-A group than that in the RIF + NO PGT-A group (47.6% vs. 24.6%, p = 0.014). After 3 cycles of FET, RIF + PGT-A group had significantly higher conservative CLBR and optimal CLBR compared to the RIF + NO PGT-A group (69.0% vs. 32.7%, p = 0.002 and 73.7% vs. 57.5%, p = 0.016), but had similar conservative and optimal CLBRs compared to the NO RIF + PGT-A group. The number of FET cycles required when half women achieved a live birth was 1 in the PGT-A group and 3 in RIF + NO PGT-A group. The miscarriage rates were not different between the RIF + PGT-A and RIF + NO PGT-A, RIF + PGT-A and NO RIF + PGT-A groups.

CONCLUSION

PGT-A did be superior in reducing the number of transfer cycles required to achieve a similar live birth rate. Further studies to identify the RIF patients who would benefit most from PGT-A are necessary.

International Natural Procreative Technology Evaluation and Surveillance of Treatment for Subfertility (iNEST): enrollment and methods

STUDY QUESTION

What is the feasibility of a prospective protocol to follow subfertile couples being treated with natural procreative technology for up to 3 years at multiple clinical sites?

SUMMARY ANSWER

Overall, clinical sites had missing data for about one-third of participants, the proportion of participants responding to follow-up questionnaires during time periods when participant compensation was available (about two-thirds) was double that of time periods when participant compensation was not available (about one-third) and follow-up information was most complete for pregnancies and births (obtained from both clinics and participants).

WHAT IS KNOWN ALREADY

Several retrospective single-clinic studies from Canada, Ireland and the USA, with subfertile couples receiving restorative reproductive medicine, mostly natural procreative technology, have reported adjusted cumulative live birth rates ranging from 29% to 66%, for treatment for up to 2 years, with a mean women’s age of about 35 years.

STUDY DESIGN, SIZE, DURATION

The international Natural Procreative Technology Evaluation and Surveillance of Treatment for Subfertility (iNEST) was designed as a multicenter, prospective cohort study, to enroll subfertile couples seeking treatment for live birth, assess baseline characteristics and follow them up for up to 3 years to report diagnoses, treatments and outcomes of pregnancy and live birth. In addition to obtaining data from medical record abstraction, we sent follow-up questionnaires to participants (both women and men) to obtain information about treatments and pregnancy outcomes, including whether they obtained treatment elsewhere. The study was conducted from 2006 to 2016, with a total of 10 clinics participating for at least some of the study period across four countries (Canada, Poland, UK and USA).

PARTICIPANTS/MATERIALS, SETTING, METHODS

The 834 participants were subfertile couples with the woman’s age 18 years or more, not pregnant and seeking a live birth, with at least one clinic visit. Couples with known absolute infertility were excluded (i.e. bilateral tubal blockage, azoospermia). Most women were trained to use a standardized protocol for daily vulvar observation, description and recording of cervical mucus and vaginal bleeding (the Creighton Model FertilityCare System). Couples received medical and sometimes surgical evaluation and treatments aimed to restore and optimize female and male reproductive function, to facilitate in vivo conception.

MAIN RESULTS AND THE ROLE OF CHANCE

The mean age of women starting treatment was 34.0 years; among those with additional demographic data, 382/478 (80%) had 16 or more years of education, and 199/659 (30%) had a prior live birth. Across 10 clinical sites in four countries (mostly private clinical practices) with family physicians or obstetrician–gynecologists, data about clinic visits were submitted for 60% of participants, and diagnostic data for 77%. For data obtained directly from the couple, 59% of couples had at least one follow-up questionnaire, and the proportion of women and men responding to fill out the follow-up questionnaires was 69% and 67%, respectively, when participant financial compensation was available, compared to 38% and 33% when compensation was not available. Among all couples, 57% had at least one pregnancy and 44% at least one live birth during the follow-up time period, based on data obtained from clinic and/or participant questionnaires. All sites reported on female pelvic surgical procedures, and among all participants, 22% of females underwent a pelvic diagnostic and/or therapeutic procedure, predominantly laparoscopy and hysterosalpingography. Among the 643 (77%) of participants with diagnostic information, ovulation-related disorders were diagnosed in 87%, endometriosis in 31%, nutritional disorders in 47% and abnormalities of semen analysis in 24%. The mean number of diagnoses per couple was 4.7.

LIMITATIONS, REASONS FOR CAUTION

The level of missing data was higher than anticipated, which limits both generalizability and the ability to study different components of treatment and prognosis. Loss to follow-up may also be differential and introduce bias for outcomes. Most of the participating clinicians were not surgeons, which limits the opportunity to study the impact of surgical interventions. Participants were geographically dispersed but relatively homogeneous with regard to socioeconomic status, which may limit the generalizability of current and future findings.

WIDER IMPLICATIONS OF THE FINDINGS

Multicenter studies are key to understanding the outcomes of subfertility treatments beyond IVF or IUI in broader populations, and the association of different prognostic factors with outcomes. We anticipate that the iNEST study will provide insight for clinical and treatment factors associated with outcomes of pregnancy and live birth, with appropriate attention to potential biases (including adjustment for potential confounders, multiple imputation for missing data, sensitivity analysis and inverse probability weighting for potential differential loss to follow-up, and assessments for clinical site heterogeneity). Future studies will need to either have: adequate funding to compensate clinics and participants for robust data collection, including targeted randomized trials; or a scaled-down, registry-based approach with targeted data points, similar to the multiple national and regional ART registries.

STUDY FUNDING/COMPETING INTEREST(S)

Funding for the study came from the International Institute for Restorative Reproductive Medicine, the University of Utah, Department of Family and Preventive Medicine, Health Studies Fund, the Primary Children’s Medical Foundation, the Mary Cross Tippmann Foundation, the Atlas Foundation, the St. Augustine Foundation and the Women’s Reproductive Health Foundation. The authors declare no competing interests.

TRIAL REGISTRATION NUMBER

The iNEST study is registered at clinicaltrials.gov, NCT01363596.

Study design flaws and statistical challenges in evaluating fertility treatments

Health interventions should be tested before being introduced into clinical practice, to find out whether they work and whether they are harmful. However, research studies will only provide reliable answers to these questions if they are appropriately designed and analysed. But these are not trivial tasks. We review some methodological challenges that arise when evaluating fertility interventions and explain the implications for a non-statistical audience. These include flexibility in outcomes and analyses; use of surrogate outcomes instead of live birth; use of inappropriate denominators; evaluating cumulative outcomes and time to live birth; allowing each patient or couple to contribute to a research study more than once. We highlight recurring errors and present solutions. We conclude by highlighting the importance of collaboration between clinical and methodological experts, as well as people with experience of subfertility, for realising high-quality research.

Lay summary

We do research to find out whether fertility treatments are beneficial and to make sure they don't cause harm. However, research will only provide reliable answers if it is done properly. It is not unusual for researchers to make mistakes when they are designing research studies and analysing the data that we get from them. In this review, we describe some of the mistakes people make when they do research about fertility treatments and explain how to avoid them. These include challenges which arise due to the large number of things that can be measured and reported when looking to see if fertility treatments work; failure to check whether the treatment increases the number of live births; failing to include all study participants in calculations;challenges in studies where participants may have more than one treatment attempt. We conclude by highlighting the importance of collaboration between clinical and methodological experts, as well as people with experience of fertility problems.

The role of maternal preconception vitamin D status in human offspring sex ratio

Evolutionary theory suggests that some animal species may experience shifts in their offspring sex ratio in response to maternal health and environmental conditions, and in some unfavorable conditions, females may be less likely to bear sons. Experimental data in both animals and humans indicate that maternal inflammation may disproportionately impact the viability of male conceptuses; however, it is unknown whether other factors associated with both pregnancy and inflammation, such as vitamin D status, are associated with the offspring sex ratio. Here, we show that among 1,228 women attempting pregnancy, preconception 25-hydroxyvitamin D concentrations are positively associated with the live birth of a male infant, with notably stronger associations among women with elevated high sensitivity C-reactive protein, a marker of systemic low-grade inflammation. Our findings suggest that vitamin D may mitigate maternal inflammation that would otherwise be detrimental to the implantation or survival of male conceptuses in utero.

Immunoreactivity of Plasminogen Activator Inhibitor 1 and Its Correlation with Dysmenorrhea and Lesional Fibrosis in Adenomyosis

Adenomyosis is associated with dysmenorrhea, infertility, and lesional fibrosis. The pathogenesis of adenomyosis is still unclear. Plasminogen activator inhibitor 1 (PAI-1) plays important roles in pathological activities like tumor metastasis and endometriosis. Our objective was to investigate the expression and localization of PAI-1 in eutopic and ectopic endometrium with adenomyosis and in endometrium without adenomyosis. We also sought to determine the relationship between PAI-1 immunoreactivity and the severity of dysmenorrhea and the extent of lesional fibrosis in adenomyosis. PAI-1 expression was significantly higher in the ectopic endometrium of patients with adenomyosis than in both the eutopic endometrium of patients with adenomyosis and the endometrium of controls. Ectopic PAI-1 expression correlated positively with dysmenorrhea visual analog scale (VAS) scores and the extent of lesional fibrosis in adenomyosis. High PAI-1 expression increased the likelihood of moderate to severe dysmenorrhea in adenomyosis. These results suggest that PAI-1 is involved in the adenomyosis-associated dysmenorrhea and lesional fibrosis, which provide a potential target in treating symptomatic adenomyosis.

Cumulative live-birth, perinatal and obstetric outcomes for POSEIDON groups after IVF/ICSI cycles: a single-center retrospective study

Recently, perinatal outcomes and cumulative live birth rate (CLBR) have widely been utilized to assess the fertility outcomes and safety of assisted reproductive technology (ART), but more robust research is needed to address the success rates of live-healthy births resulting from this procedure, particularly for patients with low prognosis. This study aims to assess and comparative perinatal outcomes and CLBR per cycle of in vitro fertilization/Intracytoplasmic sperm injection (IVF/ICSI) between four groups of low prognosis characterized by POSEIDON criteria. A retrospective assessment was done among infertile women with a low prognosis undergoing IVF/ICSI at a reproductive center in China. Data were collected between January 2011 and December 2015 with a follow-up of at least two years, and censoring was defined by three-cycle completion, discontinuation, or having a live birth. Participants were grouped into 4 groups according to the POSEIDON classification (POSEIDON1, POSEIDON2, POSEIDON3, and POSEIDON4). The main outcomes were perinatal and obstetric outcomes with CLBR per cycle after IVF/ICSI procedure. And IVF/ICSI-technique outcomes as a secondary outcome. Statistical analyses were performed by SPSS, and a p value of < 0.05 was considered significant. A total of 461 eligible participants underwent a total of 825 IVF/ICSI cycles. POSEIDON1 had the best perinatal outcomes in terms of live births (≥ 28w) (54.8%). POSEIDON4 had a higher risk for perinatal and obstetric complications with abortion rate (9.8%); LBW (11.7%), PTD (23.5%), PROM (11.7%), and gestational diabetes (17.6%). POSEIDON2 had a high rate for malpresentation (14.2%), and cesarean delivery(57.2%), while POSEIDON3 was much associated with the occurrences of placenta previa (9.3%) compared to other groups (p value = 0.001). After adjusting odds ratio by age and BMI, POSEIDON4 had the least odds for biochemical pregnancy (p value = 0.019); and the least odds for clinical pregnancy (p value = 0.001) of the four groups. CLBR per cycle was better in POSEIDON1 and increased with an increasing number of cycles in all groups during the three cycles. Conservative CLBR after three complete cycles were 77.27%, 42.52%, 51.4% and 22.34%, while optimistic CLBR were 79.01%, 51.19%, 58.59% and 34.46% in POSEIDON1 to POSEIDON4, respectively. Younger women with low prognosis and normal ovarian reserve have a higher probability for live births and better perinatal outcomes compared with older women with poor or normal ovarian reserve. Besides, young women with low prognosis, despite ovarian reserve status, can increase their probability of conception and get relatively higher CLBR by undergoing multiple cycles of IVF/ICSI. Age is therefore considered as a critical parameter in predicting the perinatal outcome and CLBR.

Choice of statistical model in observational studies of ART

Analyzing data on ART presents unique and sometimes complicated challenges related to choosing the unit(s) of analysis and the statistical model. In this commentary, we provide examples of how these challenges arise and guidance for overcoming them. We discuss the implications of different ways to count treatment cycles, considering the perspectives of research questions, data management and analysis and patient counseling. We present the advantages and disadvantages of different statistical models, and finally, we discuss the definition and calculation of the cumulative incidence of live birth, which is a key outcome of research on ART.

Cumulative probabilities of live birth across multiple complete IVF/ICSI cycles: a call for attention

PURPOSE

To call attention to the fact that cumulative live birth (LB) proportions exhibit an inverted pattern to that displayed by each individual oocyte retrieval cycle (ORC-specific LB proportions) as well as when grouping together all the ORCs undergone by a woman (TNORC-specific LB proportions).

METHODS

A retrospective study of 1433 infertile women that had a LB using autologous fresh or frozen embryos and/or dropped out of IVF/ICSI treatment after completing a maximum number of three treatment cycles. Generalized Estimating Equations (GEE) and standard and landmark Kaplan-Meier survival analyses were applied.

RESULTS

A standard Kaplan-Meier analysis indicated that cumulative LB proportions rose as number of ORCs increased (0.320, 0.484, and 0.550 at ORC 1, 2, and 3, respectively). In contrast, landmark ORC-specific LB proportions showed an inverted pattern (0.320, 0.242, and 0.127 at ORC 1, 2, and 3, respectively). GEE models revealed that women's clinical outcomes decreased as TNORCs increased. In particular, compared to women that experienced just one ORC, women that underwent two and three ORCs displayed higher incidences of cycle cancellations before either oocyte retrieval or embryo transfer, and clinical pregnancy losses, and lower odds of LB.

CONCLUSION

Infertile women should be informed that cumulative LB probabilities exhibit an inverted pattern to that displayed by each individual ORC as well as when grouping together all the ORCs undergone by a woman.

A predictive model for women's assisted fecundity before starting the first IVF/ICSI treatment cycle

PURPOSE

To introduce a prognostic model for women's assisted fecundity before starting the first IVF/ICSI treatment cycle.

METHODS

In contrast to previous predictive models, we analyze two groups of women at the extremes of prognosis. Specifically, 708 infertile women that had either a live birth (LB) event in the first autologous IVF/ICSI cycle ("high-assisted-fecundity women", n = 458) or did not succeed in having a LB event after completing three autologous IVF/ICSI cycles ("low-assisted-fecundity women", n = 250). The initial sample of 708 women was split into two sets in order to develop (n = 531) and internally validate (n = 177) a predictive logistic regression model using a forward-stepwise variable selection.

RESULTS

Seven out of 32 initially selected potential predictors were included into the model: women's age, presence of multiple female infertility factors, number of antral follicles, women's tobacco smoking, occurrence of irregular menstrual cycles, and basal levels of prolactin and LH. The value of the c-statistic was 0.718 (asymptotic 95% CI 0.672-0.763) in the development set and 0.649 (asymptotic 95% CI: 0.560-0.738) in the validation set. The model adequately fitted the data with no significant over or underestimation of predictor effects.

CONCLUSION

Women's assisted fecundity may be predicted using a relatively small number of predictors. This approach may complement the traditional procedure of estimating cumulative and cycle-specific probabilities of LB across multiple complete IVF/ICSI cycles. In addition, it provides an easy-to-apply methodology for fertility clinics to develop and actualize their own predictive models.

Methodological approaches to analyzing IVF data with multiple cycles

STUDY QUESTION

Which methodological approaches are most appropriate for analyzing IVF data with multiple cycles in the context of a binary outcome?

SUMMARY ANSWER

Both mixed effect models and generalized estimating equation (GEE) modeling approaches can account for multiple IVF cycles and may reduce bias over first-cycle only approaches, but CIs were narrowest with cluster-weighted generalized estimating equation models (CWGEE).

WHAT IS KNOWN ALREADY

There is a lack of consensus among investigators regarding how to best incorporate data from multiple cycles and whether to present odds or risks in the analysis of IVF data. Failure to account for correlated outcomes within individuals and informative cluster size may lead to invalid CIs and biased estimates.

STUDY DESIGN, SIZE, DURATION

The Environment and Reproductive Health (EARTH) Study is an ongoing prospective cohort study of subfertile couples conducted at an academic medical center. This cohort was established in 2004 and follows couples seeking treatment for infertility throughout the course of their treatment and pregnancy.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Women aged 18-46 years enrolled in the EARTH Study from 2004 to 2017 who initiated at least one IVF cycle were eligible. Cycle initiation was defined as beginning ovulation induction with the intent to progress through an IVF or ICSI cycle. This analysis included 442 women undergoing 642 cycles who met the study inclusion criteria. We compared the results and interpretations of log-binomial and logistic models restricting to the first cycle, as well as mixed effects models, unweighted GEE models, and CWGEE models including all cycles. This analysis was conducted for two distinct exposures: maternal age at cycle initiation, and maternal preconception urinary concentrations of di(2-ethylhexyl) phthalate (DEHP) metabolites (previously reported to be associated with a decreased probability of live birth).

MAIN RESULTS AND THE ROLE OF CHANCE

In general, the CIs were widest for mixed effects models and narrowest for CWGEE models. Further, in models evaluating the sum of urinary concentrations of DEHP metabolites (∑DEHP, available for 91% of women), the point estimates were surprisingly different between the first-cycle and multiple-cycle models. We observed significant associations between maternal age and live birth in all models. However, we observed no associations between ∑DEHP and live birth.

LIMITATIONS, REASONS FOR CAUTION

This analysis was limited to an example dataset in which the true effect of any exposure is unknown. While this allows us to observe model performance in the context of real data, future analyses should be conducted within simulated datasets under various assumptions to further evaluate the appropriateness of each approach. In addition, we did not address differential loss to follow-up in our statistical approaches.

WIDER IMPLICATIONS OF THE FINDINGS

The use of CWGEE models should be more widely considered in the analysis of IVF data with multiple cycles per woman. The CWGEE approach is computationally simple, addresses non-ignorable (informative) cluster size, and is robust against mis-specification of the underlying covariance structure. Among the methods compared in this analysis, CWGEE models generally yielded the narrowest CIs, possibly indicating the most precise estimates. We also stress the importance of estimating risks rather than odds in the analysis of IVF data.

STUDY FUNDING/COMPETING INTEREST(S)

The project was funded by Grants (R01ES022955, R01ES009718, and P30ES000002) from the National Institutes of Health. None of the authors has any conflicts of interest to declare.