Methods for a Retrospective Population-based and Clinic-based Subfertility Cohort Study: the Fertility Experiences Study

Large-Scale Data Harmonization Across Prospective Studies

The Preconception Period Analysis of Risks and Exposures Influencing Health and Development (PrePARED) Consortium creates a novel resource for addressing preconception health by merging data from numerous cohort studies. In this paper, we describe our data harmonization methods and results. Individual-level data from 12 prospective studies were pooled. The crosswalk-cataloging-harmonization procedure was used. The index pregnancy was defined as the first postbaseline pregnancy lasting more than 20 weeks. We assessed heterogeneity across studies by comparing preconception characteristics in different types of studies. The pooled data set included 114,762 women, and 25,531 (22%) reported at least 1 pregnancy of more than 20 weeks' gestation during the study period. Babies from the index pregnancies were delivered between 1976 and 2021 (median, 2008), at a mean maternal age of 29.7 (standard deviation, 4.6) years. Before the index pregnancy, 60% of women were nulligravid, 58% had a college degree or more, and 37% were overweight or obese. Other harmonized variables included race/ethnicity, household income, substance use, chronic conditions, and perinatal outcomes. Participants from pregnancy-planning studies had more education and were healthier. The prevalence of preexisting medical conditions did not vary substantially based on whether studies relied on self-reported data. Use of harmonized data presents opportunities to study uncommon preconception risk factors and pregnancy-related events. This harmonization effort laid the groundwork for future analyses and additional data harmonization.

Associations between lifestyle factors and levels of per- and polyfluoroalkyl substances (PFASs), phthalates and parabens in follicular fluid in women undergoing fertility treatment

BACKGROUND

Concerns have been raised whether exposure to endocrine-disrupting chemicals (EDCs) can alter reproductive functions and play a role in the aetiology of infertility in women. With increasing evidence of adverse effects, information on factors associated with exposure is necessary to form firm recommendations aiming at reducing exposure.

OBJECTIVE

Our aim was to identify associations between lifestyle factors including the home environment, use of personal care products (PCP), and dietary habits and concentrations of EDCs in ovarian follicular fluid.

METHODS

April-June 2016, 185 women undergoing ovum pick-up for in vitro fertilisation in Sweden were recruited. Correlation analyses were performed between self-reported lifestyle factors and concentration of EDCs analysed in follicular fluid. Habits related to cleaning, PCPs, and diet were assessed together with concentration of six per- and polyfluoroalkyl substances (PFASs) [PFHxS, PFOA, PFOS, PFNA, PFDA and PFUnDA], methyl paraben and eight phthalate metabolites [MECPP, MEHPP, MEOHP, MEHP, cxMinCH, cxMiNP, ohMiNP, MEP, MOHiBP]. Spearman's partial correlations were adjusted for age, parity and BMI.

RESULTS

Significant associations were discovered between multiple lifestyle factors and concentrations of EDCs in ovarian follicular fluid. After correcting p values for multiple testing, frequent use of perfume was associated with MEP (correlation ρ = 0.41 (confidence interval 0.21-0.47), p < 0.001); hens' egg consumption was positively associated with PFOS (ρ = 0.30 (0.15-0.43), p = 0.007) and PFUnDA (ρ = 0.27 (0.12-0.40), p = 0.036). White fish consumption was positively associated with PFUnDA (ρ = 0.34 (0.20-0.47), p < 0.001) and PFDA (ρ = 0.27 (0.13-0.41), p = 0.028). More correlations were discovered when considering the raw uncorrected p values. Altogether, our results suggest that multiple lifestyle variables affect chemical contamination of follicular fluid.

IMPACT STATEMENT

This study shows how lifestyle factors correlate with the level of contamination in the ovary by both persistent and semi-persistent chemicals in women of reproductive age. Subsequently, these data can be used to form recommendations regarding lifestyle to mitigate possible negative health outcomes and fertility problems associated with chemical exposure, and to inform chemical policy decision making. Our study can also help form the basis for the design of larger observational and intervention studies to examine possible effects of lifestyle changes on exposure levels, and to unravel the complex interactions between biological factors, lifestyle and chemical exposures in more detail.

An In Vivo Screening Model for Investigation of Pathophysiology of Human Implantation Failure

To improve current infertility treatments, it is important to understand the pathophysiology of implantation failure. However, many molecules are involved in the normal biological process of implantation and the roles of each molecule and the molecular mechanism are not fully understood. This review highlights the hemagglutinating virus of Japan (HVJ; Sendai virus) envelope (HVJ-E) vector, which uses inactivated viral particles as a local and transient gene transfer system to the murine uterus during the implantation period in order to investigate the molecular mechanism of implantation. In vivo screening in mice using the HVJ-E vector system suggests that signal transducer and activator of transcription-3 (Stat-3) could be a diagnostic and therapeutic target for women with a history of implantation failure. The HVJ-E vector system hardly induces complete defects in genes; however, it not only suppresses but also transiently overexpresses some genes in the murine uterus. These features may be useful in investigating the pathophysiology of implantation failure in women.

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.

Introducing the Hungarian Version of the SCREENIVF Tool into the Clinical Routine Screening of Emotional Maladjustment

Examining possible psychosocial maladjustments should be an integral part of fertility care. For the early detection of vulnerability, the present study aimed to adapt and test the reliability and validity of the Hungarian version of SCREENIVF against the Fertility Quality of Life Questionnaire (FertiQoL) in a cross-sectional on subfertile women (n = 60, age 34.6 ± 5.2 years, BMI 24.2 ± 4.9 kg/m2) at a university linked fertility clinic in South-Hungary. A confirmatory factor analysis (CFA) was conducted to investigate the construct validity. For the reliability testing, Cronbach alpha values were calculated. Spearman’s rank correlation tested the criterion validity. Discriminant validity was applied using Mann−Whitney U-test and Kruskal−Wallis test. The Edinburgh Framework and COSMIN checklist were applicable for the analysis using SPSS 27.0; significance was set at p < 0.05. The confirmatory factor analysis indicated a good fit; all dimensions were reliable (α ≥ 0.70). Cronbach’s alpha was excellent (0.825−0.904). Strong correlations were found between the total scale (FertiQoL) and anxiety (R = −0.507, p < 0.001), depression (R = 0.554, p < 0.001), and helplessness cognitions (R = −0.747, p < 0.001) and moderate or no correlation with acceptance cognitions (R = 0.317, p = 0.015) and social support (R = 0.230, p = 0.082). The Hungarian version of SCREENIVF proved a valid and reliable tool to measure psychological maladjustment before ART. A longitudinal, randomized, controlled trial involving the partners could further strengthen the results, which is among our long-term plans.

Fertility treatments and the risk of preterm birth among women with subfertility: a linked-data retrospective cohort study

Background

In vitro fertilization (IVF) births contribute to a considerable proportion of preterm birth (PTB) each year. However, there is no formal surveillance of adverse perinatal outcomes for less invasive fertility treatments. The study objective was to describe associations between fertility treatment (in vitro fertilization, intrauterine insemination, usually with ovulation drugs (IUI), or ovulation drugs alone) and preterm birth, compared to no treatment in subfertile women.

Methods

The Fertility Experiences Study (FES) is a retrospective cohort study conducted at the University of Utah between April 2010 and September 2012. Women with a history of primary subfertility self-reported treatment data via survey and interviews. Participant data were linked to birth certificates and fetal death records to asses for perinatal outcomes, particularly preterm birth.

Results

A total 487 birth certificates and 3 fetal death records were linked as first births for study participants who completed questionnaires. Among linked births, 19% had a PTB. After adjustment for maternal age, paternal age, maternal education, annual income, religious affiliation, female or male fertility diagnosis, and duration of subfertility, the odds ratios and 95% confidence intervals (CI) for PTB were 2.17 (CI 0.99, 4.75) for births conceived using ovulation drugs, 3.17 (CI 1.4, 7.19) for neonates conceived using IUI and 4.24 (CI 2.05, 8.77) for neonates conceived by IVF, compared to women with subfertility who used no treatment during the month of conception. A reported diagnosis of female factor infertility increased the adjusted odds of having a PTB 2.99 (CI 1.5, 5.97). Duration of pregnancy attempt was not independently associated with PTB. In restricting analyses to singleton gestation, odds ratios were not significant for any type of treatment.

Conclusion

IVF, IUI, and ovulation drugs were all associated with a higher incidence of preterm birth and low birth weight, predominantly related to multiple gestation births.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12978-022-01363-4.

Infertility treatments such as in vitro fertilization are associated with preterm birth, but less is known about how other less invasive treatments contribute to preterm birth. This study compares different types of fertility treatments and rates of preterm birth with women who are also struggling with infertility but did not use fertility treatments at the time of their pregnancy. 490 women were recruited at the University of Utah between 2010 and 2012. Participants were asked to complete a survey and were linked to birth certificate and fetal death certificate data. Women who used in vitro fertilization were 4.24 times more likely to have a preterm birth than those who used no treatment. Use of intrauterine insemination were 3.17 times more likely to have a preterm birth than those who used no treatment at time of conception. Ovulation stimulating drugs were 2.17 times more likely to have a preterm birth. Having female factor infertility was also associated with higher odds of having preterm birth. For those who are having trouble conceiving, trying less invasive treatments to achieve pregnancy might reduce their risk of preterm birth.

On estimating the prevalence of use of medically assisted reproduction in developed countries: a critical review of recent literature

BACKGROUND

Existing reviews on the prevalence of use of medically assisted reproduction (MAR) are relatively old and include mainly studies from the 1980s and 1990s. Since then, MAR has developed at a rapid pace, public awareness and acceptance of medical solutions to infertility problems has increased, and, consequently, the use of MAR has risen in developed countries.

OBJECTIVE AND RATIONALE

This study provides a comprehensive overview of the state of research on the prevalence of MAR use in women and men, as well as a critique of methodology used in studies of the use of MAR, and suggestions for moving forward.

SEARCH METHODS

Articles were located via the databases Academic Search Complete, Biomed Central, FirstSearch, Google Scholar, Medline, Health and Medical Collection, Medline and Social Science Citation Index using the key words 'infertile', 'infertility', 'subfecund', 'subfecundity', 'treatment', 'help-seeking', 'service use', 'service utilization', 'ART use' and 'MAR use' separately and in various combinations. The focus was on studies from developed countries, published between 1990 and 2018, in English, German or French.

OUTCOMES

In this article, we have reviewed 39 studies covering 13 countries or regions; approximately half of these covered the USA. Ten studies were published in the 1990s, 10 in the 2000s and 19 since 2010. Studies report different types of prevalence rates such as lifetime and current prevalence rates of MAR use. Prevalence rates are based on very different denominators: women who tried to become pregnant for at least 12 months without success, women who experienced at least 12 months of unprotected intercourse without success, women of reproductive age from the general population or women with a life birth. There are few studies that report help-seeking rates for men or make direct comparisons between genders. Knowledge on medical help-seeking across different stages, such as seeing a doctor, undergoing tests, having operations to restore fertility or ART, has started to accumulate in recent years. There are conceptual reasons for being cautious about drawing conclusions about gender, regional, country level and differences over time in help-seeking rates.

LIMITATIONS REASONS FOR CAUTION

In a narrative review, the risk of bias in the interpretation of findings cannot be completely eliminated. The literature search was limited to languages the authors speak: English, French and German.

WIDER IMPLICATIONS

In line with earlier reviews, we found that studies on help-seeking are not comparable across time and space, preventing researchers and healthcare providers from understanding the relation between social change, social policy, social structure and help-seeking for infertility. The discussion in this article should assist future researchers in designing better studies on the prevalence of MAR use. We provide suggestions for producing better estimates of the prevalence of MAR use. More cross-country and cross-gender comparisons are needed. Studies that treat help-seeking as a continuum and report on different stages are preferable compared to choosing arbitrary cutoff points, as is common practice in the studies reviewed.

STUDY FUNDING/COMPETING INTERESTS

None.

Fertility Treatment, Use of in Vitro Fertilization, and Time to Live Birth Based on Initial Provider Type

PURPOSE

To explore the relationship between the type of clinician (generalist vs subspecialist) initially seen by infertile women, the treatment received, and the time to pregnancy.

METHODS

We analyzed mixed-mode questionnaire data from 867 women with primary infertility enrolled into a retrospective cohort through population- and fertility clinic-based sampling. We compared women presenting first to generalist providers with women presenting first to fertility subspecialists, with the main outcomes of receiving in vitro fertilization (IVF), time to pregnancy, and live birth.

RESULTS

The first contact for most (84%) women with infertility was a generalist provider. Only 8% of women sought care first from a fertility subspecialist, and these women were older and had been trying longer to conceive. Women who presented first to a generalist provider were less likely to receive IVF (adjusted odds ratio, 0.48; 95% confidence interval, 0.28-0.82), were equally likely to achieve pregnancy, and had similar times to pregnancy (adjusted hazard ratio, 1.11; 95% confidence interval, 0.80-1.53) compared with women who presented first to a subspecialist.

CONCLUSIONS

Generalist providers are frequently the first point of care for women with difficulty conceiving and are uniquely positioned to promote the balanced management of infertility.