Current Duration Approach Research Articles

Measuring non-events: infertility estimation using cross-sectional, population-based data from four countries in sub-Saharan Africa.

Does the prevalence of 12-month infertility in Burkina Faso, Côte d'Ivoire, Kenya, and Uganda differ between women trying to conceive and the broader population of women exposed to unprotected sex, and how are prevalence estimates affected by model assumptions and adjustments? Estimates of 12-month infertility among tryers ranged from 8% in Burkina Faso to 30% in Côte d'Ivoire, increasing substantially among a larger population of women exposed to unprotected intercourse. While having a child is a fundamental human experience, the extent to which women and couples experience infertility is a neglected area of research, particularly in sub-Saharan Africa. Existing estimates of infertility in this region vary widely from 2% to 32%, however, potential impacts of variability in study populations and model assumptions have not been well-examined. We used cross-sectional nationally representative survey data from Burkina Faso, Côte d'Ivoire, Kenya, and Uganda. We employed a multi-stage cluster random sampling design with probability proportional to the size selection of clusters within each country to produce representative samples of women aged 15-49. Samples ranged from 3864 in Côte d'Ivoire to 9489 in Kenya. We created two analytic samples in each country-tryers and a broader sample of women exposed to unprotected sex-exploring differences in population characteristics and estimating the period prevalence of 12-month infertility using the current duration (CD) approach. We also examined the impact of several model assumptions within each of the two analytic samples, including adjustments for recent injectable contraceptive use, unrecognized pregnancy, infertility treatment, underreported contraceptive use, and sexual activity. Employing the CD approach among tryers produced an overall 12-month infertility prevalence of 7.9% (95% CI 6.6-12.7) in Burkina Faso, 29.6% (95% CI 15.3-100.0) in Côte d'Ivoire, 24.5% (95% CI 16.5-34.6) in Kenya, and 14.7% (95% CI 8.1-22.4) in Uganda. Results among women exposed to unprotected intercourse indicated much higher levels of infertility, ranging from 22.4% (95% CI 18.6-30.8) in Uganda to 63.7% (95% CI 48.8-87.9) in Côte d'Ivoire. Sensitivity analyses suggest infertility estimates are particularly sensitive to adjustments around pregnancy recognition timing and sexual activity, with little impact of adjustments for recent injectable contraceptive use, infertility treatment, and underreporting of traditional and coital dependent contraceptive use. There was substantial digit preference in responses at 12 months, particularly among the tryers, which could introduce bias. Data quality concerns in the reproductive calendar may impact the accuracy of the CD approach among the broader sample of women exposed to unprotected sex, particularly with regard to underreported contraceptive use, induced and spontaneous abortions, and unrecognized pregnancies. Lastly, we lacked information on postpartum amenorrhea or abstinence. Understanding the inconsistencies in definition and analytic approach and their implications for infertility estimation is important for reliably monitoring population-level infertility trends, identifying factors influencing infertility, improving prevention programs, and ensuring access to quality treatment and services. This study was supported by grants from the Bill & Melinda Gates Foundation (INV009639) and the National Institute of Child Health and Human Development (K01HD107172). The funders were not involved in the study design, analyses, manuscript writing, or the decision to publish. The authors have no conflicts of interest to declare. N/A.

Estimation of couple fecundity in the general population and the association with monthly time-varying ambient particulate matter exposure in low- and middle-income countries: A population-based multi-center epidemiological study

BackgroundDeclining total fertility rates have been observed in low- and middle-income countries (LMICs). However, it remains unclear if this trend is related to a reduction in fecundity of general population. Research evidence on contributing factors to fecundity reduction is also limited. We aimed to first estimate couple fecundity in LMICs and then investigate its association with ambient particulate matter (PM) exposure. MethodsUsing the information from Demographic and Health Surveys between 2003 and 2019, we estimated median time to pregnancy (TTP) and infertility prevalence across 30 LMICs, by employing a current duration approach. Individual PM (PM1, PM2.5, and PM10) exposure during the period of ‘at risk’ of pregnancy was assessed by months. An accelerated failure model was used to elucidate the association between monthly time-varying PM exposure and TTP. Subsequently, we estimated the prolonged TTP attributable to PM exposures above the World Health Organization (WHO)’s recommended air quality level in 2021. ResultsWithin the study regions, median TTP ranged from 6.90 (95 % CI 6.02–7.87) months in Latin America & Caribbean to 10.29 (95 % CI 9.28–11.36) months in East Asia & Pacific, with corresponding infertility prevalence varying from 33 % (95 % CI 29 %–36 %) to 44 % (95 % CI 41 %–48 %). Our estimations indicated that TTP was 1.08 (95 % CI: 0.99–1.18), 1.12 (95 % CI 1.06–1.19), and 1.05 (95 % CI 1.03–1.07) times longer for every 10 μg/m3 increment in PM1, PM2.5, and PM10, respectively. The prolonged TTP attributable to PM exposures surpassing the WHO guideline ranged from 0.11 to 2.81 months across the studied regions. DiscussionAmbient particulate matter is identified as a potential contributing factor to impaired fecundity in general population of LMICs. The findings underscore the importance of coordinated efforts to control ambient air pollution to mitigate the risk of fecundity reduction among the general population.

P-465 Rehabilitation services and the infertility journey: a study on women’s experiences in Ethiopia

Abstract Study question How does infertility affect women in Ethiopia, and can rehabilitation service providers mitigate its impact? Summary answer Introducing rehabilitation services for women with infertility in Ethiopia could mitigate the frequent adverse psychosocial consequences and maintain women’s integration into family and community structures. What is known already Infertility is a disease that generates a disability as an impairment of function. Globally, millions of people are affected, and women bear the brunt of its consequences. In Ethiopia, infertility can cause significant distress and burden for women who are unable to meet societal expectations of motherhood. Despite this impact, no previous research has been conducted in Ethiopia to explore the role of rehabilitation services in providing support for these women. Study design, size, duration We followed a sequential mixed methods design that consisted of three parts: The national prevalence of infertility in Ethiopia was first determined using data from the 2016 Ethiopian Demographic and Health Survey (DHS); using Interpretive Phenomenology, the lived experiences of Ethiopian women living with infertility was explored; and finally, an Interpretive Description approach was applied to evaluate the role of rehabilitation services in assisting women with infertility. Data were collected between 2022 and 2023. Participants/materials, setting, methods For the first part, we performed secondary data analysis from 15,683 women in Ethiopia through the 2016 Ethiopian DHS. The data were analyzed using two approaches to infertility – the demographic and current duration. In the second part, 13 women undergoing treatment at a fertility center were interviewed. In the third part, 14 rehabilitation, medical, and policy service providers were purposefully selected from diverse institutions across three different geographical locations in Ethiopia. Main results and the role of chance Using the demographic definition, the overall prevalence of infertility was 7.6% (95% CI 6.6-8.8), with a prevalence of primary and secondary infertility of 1.4% (95% CI 1.0-1.9) and 8.7% (95% CI 7.5-10.1), respectively. The current duration approach resulted in a prevalence of overall infertility of 24.1% (95% CI 18.8-34.0) at 12-months, 13.4% (95% CI 10.1-18.6) at 24-months, and 8.8% (95% CI 6.5- 12.3) at 36-months. Thus, the demographic definition resulted in a lower estimate compared to the current duration approach which could be more appropriate for the early detection and management of infertility in Ethiopia. According to participants, infertility had far-reaching consequences that substantially affected women’s psychological, socio-cultural, and spiritual lives. Despite this, women developed various coping mechanisms and resilience. Women had minimal access to psychosocial and financial support and no access to rehabilitation services. Finally, interviewees recognized the potential of rehabilitation services to maximize the day-to-day functioning and overall well-being of women with infertility. Limitations, reasons for caution Using demographic proxies to determine exposure to pregnancy can make estimation unreliable. The fertility center only treated married couples; hence, single, separated, or divorced women were not included. Results are context-specific and cannot be extrapolated to all infertility cases in Ethiopia or elsewhere. Wider implications of the findings This is the first study to explore infertility in Ethiopia from a rehabilitation perspective. Based on the prevalence and impact, infertility in Ethiopia represents a major public health issue. Strengthening policies, integrating rehabilitation services into fertility care, and recognizing infertility as a disabling condition are crucial steps toward addressing infertility. Trial registration number not applicable

The varying estimation of infertility in Ethiopia: the need for a comprehensive definition

BackgroundInfertility is a marginalized sexual and reproductive health issue in low-resource settings. Globally, millions are affected by infertility, but the lack of a universal definition makes it difficult to estimate the prevalence of infertility at the population level. Estimating the prevalence of infertility may inform targeted and accessible intervention, especially for a resource-limited country like Ethiopia. This study aims to estimate the prevalence of female infertility in Ethiopia using the Demographic and Health Survey (DHS) through two approaches: (i) the demographic approach and (ii) the current duration approach.MethodsData from 15,683 women were obtained through the 2016 Ethiopian DHS. The demographic approach estimates infertility among women who had been married/in a union for at least five years, had never used contraceptives, and had a fertility desire. The current duration approach includes women at risk of pregnancy at the time of the survey and determines their current length of time-at-risk of pregnancy at 12, 24, and 36 months. Logistic regression analysis estimated the prevalence of infertility and factors associated using the demographic approach. Parametric survival analysis estimated the prevalence of infertility using the current duration approach. All estimates used sampling weights to account for the DHS sampling design. STATA 14 and R were used to perform the statistical analysis.ResultsUsing the demographic definition, the prevalence of infertility was 7.6% (95% CI 6.6–8.8). When stratified as primary and secondary infertility, the prevalence was 1.4% (95% CI 1.0-1.9) and 8.7% (95% CI 7.5–10.1), respectively. Using the current duration approach definition, the prevalence of overall infertility was 24.1% (95% CI 18.8–34.0) at 12-months, 13.4% (95% CI 10.1–18.6) at 24-months, and 8.8% (95% CI 6.5–12.3) at 36-months.ConclusionThe demographic definition of infertility resulted in a lower estimate of infertility. The current duration approach definition could be more appropriate for the early detection and management of infertility in Ethiopia. The findings also highlight the need for a comprehensive definition of and emphasis on infertility. Future population-based surveys should incorporate direct questions related to infertility to facilitate epidemiological surveillance.

Trends in time-to-pregnancy in the USA: 2002 to 2017.

Has there been there a temporal change in time-to-pregnancy (TTP) in the USA. Overall, TTP was stable over time, but a longer TTP for women over 30 and parous women was identified. Fertility rates in the USA have declined over the past several years. Although these trends have been attributed to changing reproductive intentions, it is unclear whether declining fecundity (the biologic ability to reproduce measured by TTP in the current report) may also play a role. Indeed, trends based on declining sperm quality and higher utilisation of infertility treatment suggest fecundity may be falling. This cross-sectional survey data from the National Survey of Family Growth was administered from 2002 to 2017. The surveys are based on nationally representative samples of reproductive-aged women in the USA. Interviews were conducted in person or through computer-assisted self-administration of sensitive questions. The study included women who self-reported time spent trying to become pregnant allowing utilisation of the current duration approach to estimate the total duration of pregnancy attempt (i.e. TTP). In all, 1202 participants were analysed over each study period. To estimate a TTP distribution overall and by parity, we used a piecewise constant proportional hazards model that accounts for digit preference. Accelerated-failure-time regression models, which were weighted to account for the sampling design, were used to estimate time ratios (TRs). Models were adjusted for age, BMI, race, education, relationship status, parity, pelvic inflammatory disease treatment and any reproductive problems. Of the participants analysed, the average age was 31.8 and BMI was 28.6, which was similar across the survey periods. Relationship status was the only demographic characteristic that changed over time. All other variables remained constant across the study periods. Overall, TRs comparing TTP between 2002 and 2017 increased slightly (TR: 1.02, 95% CI: 0.99, 1.04). When stratified by parity, parous women had a longer TTP over the later years of the study (TR: 1.04, 95% CI: 1.01, 1.06). TTP remained constant for nulliparous women. Similarly, TTP also increased over time for women over age thirty (TR: 1.02, 1.00, 1.05) but not for women under age thirty. Small changes in data collection over time may have impacted the findings. We accounted for this in sensitivity analyses using imputed data. Overall, TRs were slightly attenuated using the imputed data, but represented similar patterns to the original data. Results for parous women and women over 30 remained consistent in the sensitivity analyses. Consistent with reports of falling fertility rates and sperm counts, this study suggests parous and older couples in the USA may be taking longer to become pregnant. Although trends were suggestive of a small overall increase in TTP, particularly for parous women and women over age thirty, additional data are needed to attempt to understand these trends given the societal, economic and public health implications related to fecundity. Funding was provided by National Institutes of Health grant R03HD097287 to A.C.M. There are no competing interests. N/A.

The Use of Time to Pregnancy for Estimating and Monitoring Human Fecundity From Demographic and Health Surveys.

Available studies on the prevalence of infertility have proved to have certain limitations, with a scarcity of population-based studies and inconsistent reporting from surveys in countries at all income levels. We wanted to test the applicability of the current duration approach to data from the important Demographic and Health Surveys (DHS) program, funded by USAID since its inception in 1985, https://dhsprogram.com/. The current duration approach assumes that there is a well-defined time of initiation of attempts to get pregnant and defines the current duration of a still ongoing pregnancy attempt as the time interval from initiation to interview. The DHS interviews do not have an explicit question about initiation. We focused on nullipari and substituted date of "establishment of relationship with current partner" for initiation. Our study used the current duration approach on 15 datasets from DHS during 2002-2016 in eight different countries from sub-Saharan Africa, Asia, and Latin America. Well-established statistical techniques for current duration data yielded results that for some countries postulated surprisingly long median times to pregnancy and surprisingly high estimates of infertility prevalence. Further study of the data structures revealed serious deviations from expected patterns, in contrast to our earlier experience from surveys in France and the United States where participants were asked explicitly about time of initiation of attempts to become pregnant. Using cohabitation as a proxy for the initiation of attempts to get pregnant is too crude. Using the current duration approach with DHS data will require more explicit questions during the DHS interviews about initiation of pregnancy attempt.

Fecundity and Infertility Among Women with Disabilities in the United States.

Background: Knowledge of fecundity and infertility in women with a disability (WWD) is limited. This study aims to compare the fecundity and infertility experiences of women with a self-identified disability, in domains of sensory (hearing and vision loss), cognitive (difficulty concentrating, remembering, and making decisions), and physical (difficulty walking or climbing stairs) disabilities, with those without a self-identified disability. Materials and Methods: Cross-sectional survey data from the National Survey of Family Growth (NSFG), 2011-2015, were analyzed. A final analytic sample of 383 women from the NSFG, aged 18-44 years, was included to study the fecundity rates of WWD and women without a disability, using the current duration approach. Results: Fecundity hazard ratios (FHRs) and the proportion of women experiencing infertility after 12 months of actively attempting pregnancy were reported for the comparison group and by each disability type. Women with a self-identified cognitive disability experienced significant decreases in fecundity (FHR = 0.56; 95% confidence interval [CI]: 0.30-0.88) when adjusting for age, education level, parity, living in a metropolitan area, and infertility services. Furthermore, the estimated proportion of infertile women without a disability was 0.38 (95% CI: 0.23-0.62) versus 0.51 (95% CI: 0.34-0.72) for women with a self-identified cognitive disability. Conclusions: Women with a self-identified cognitive disability experienced significant decreases in fecundity.

PREVALENCE AND RISK FACTORS OF INFERTILITY IN TURKEY: EVIDENCE FROM DEMOGRAPHIC AND HEALTH SURVEYS, 1993-2013.

The inability to have children affects couples worldwide and causes emotional and psychological distress in both men and women. Turkey is a country that lays particular emphasis on the issue of infertility, especially after experiencing a dramatic fertility decline over the last two decades. This study aimed to understand the changes in the prevalence of infertility in Turkey using three different approaches: the DHS Approach, the Constructed Approach and the Current Duration Approach. Furthermore, the factors contributing to elevated risks of infertility as derived from the Constructed Approach were investigated using four different logistic regression models. The data came from the 1993, 1998, 2003, 2008 and 2013 Demographic and Health Surveys conducted by the Hacettepe University Institute of Population Studies. The findings of the Constructed and Current Duration Approaches suggested that the prevalence of infertility decreased markedly from 1993 to 2013 in Turkey. This decline was the result of improvements in maternal health care services in Turkey, as well as an increase in the use of Assisted Reproductive Technology (ART), from 1.9% in 2008 to 4.1% in 2013. The results of the final logistic regression model suggested that the risk of infertility was significantly higher among women aged between 35 and 49 (p<0.01), uneducated women (p<0.01), women whose age at first marriage was over 30 (p<0.01), women defined as overweight (p<0.05) and women whose age at menarche was less than 12 years (p<0.05). This is the first nationwide study to examine the prevalence of infertility and its socio-demographic risk factors in Turkey, a developing country; previous studies have established these risk factors mainly in developed countries.

Estimating infertility prevalence in low-to-middle-income countries: an application of a current duration approach to Demographic and Health Survey data.

STUDY QUESTIONCan infertility prevalence be estimated using a current duration (CD) approach when applied to nationally representative Demographic and Health Survey (DHS) data collected routinely in low- or middle-income countries?SUMMARY ANSWEROur analysis suggests that a CD approach applied to DHS data from Nigeria provides infertility prevalence estimates comparable to other smaller studies in the same region.WHAT IS KNOWN ALREADYDespite associations with serious negative health, social and economic outcomes, infertility in developing countries is a marginalized issue in sexual and reproductive health. Obtaining reliable, nationally representative prevalence estimates is critical to address the issue, but methodological and resource challenges have impeded this goal.STUDY DESIGN, SIZE, DURATIONThis cross-sectional study was based on standard information available in the DHS core questionnaire and data sets, which are collected routinely among participating low-to-middle-income countries. Our research question was examined among women participating in the 2013 Nigeria DHS (n = 38 948). Among women eligible for the study, 98% were interviewed.PARTICIPANTS/MATERIALS, SETTING, METHODSWe applied a CD approach (i.e. current length of time-at-risk of pregnancy) to estimate time-to-pregnancy (TTP) and 12-month infertility prevalence among women ‘at risk’ of pregnancy at the time of interview (n = 7063). Women who were 18–44 years old, married or cohabitating, sexually active within the past 4 weeks and not currently using contraception (and had not been sterilized) were included in the analysis. Estimates were based on parametric survival methods using bootstrap methods (500 bootstrap replicates) to obtain 95% CIs.MAIN RESULTS AND THE ROLE OF CHANCEThe estimated median TTP among couples at risk of pregnancy was 5.1 months (95% CI: 4.2–6.3). The estimated percentage of infertile couples was 31.1% (95% CI: 27.9–34.7%)—consistent with other smaller studies from Nigeria. Primary infertility (17.4%, 95% CI: 12.9–23.8%) was substantially lower than secondary infertility (34.1%, 95% CI: 30.3–39.3%) in this population. Overall estimates for TTP >24 or >36 months dropped to 17.7% (95% CI: 15.7–20%) and 11.5% (95% CI: 10.2–13%), respectively. Subgroup analyses showed that estimates varied by age, coital frequency and fertility intentions, while being in a polygynous relationship showed minimal impact.LIMITATIONS, REASONS FOR CAUTIONThe CD approach may be limited by assumptions on when exposure to risk of pregnancy began and methodologic assumptions required for estimation, which may be less accurate for particular subgroups or populations. Unrecognized pregnancies may have also biased our findings; however, we attempted to address this in our exclusion criteria. Limiting to married/cohabiting couples may have excluded women who are no longer in a relationship after being blamed for infertility. Although probably rare in this setting, we lack information on couples undergoing infertility treatment. Like other TTP measurement approaches, pregnancies resulting from contraceptive failure are not included, which may bias estimates.WIDER IMPLICATIONS OF THE FINDINGSNationally representative estimates of TTP and infertility based on a clinical definition of 12 months have been limited within developing countries. This approach represents a pragmatic advance in our ability to measure and monitor infertility in the developing world, with potentially far-reaching implications for policies and programs intended to address reproductive health.STUDY FUNDING/COMPETING INTERESTSThere are no competing interests and no financial support was provided for this study. Financial support for Open Access publication was provided by the World Health Organization.

The prevalence of couple infertility in the United States from a male perspective: evidence from a nationally representative sample.

Infertility is a couple-based fecundity impairment, although population level research is largely based upon information reported by female partners. Of the few studies focusing on male partners, most focus on the utilization of infertility services rather than efforts to estimate the prevalence and determinants of infertility as reported by male partners. Data from a nationally representative sample of men aged 15-44years who participated in the 2002 National Survey of Family Growth (NSFG) were used to estimate the prevalence of infertility and determinants of longer time-to-pregnancy (TTP) using the novel current duration (CD) approach. Using backward recurrence time parametric survival methods, we estimated infertility prevalence (TTP>12months) and time ratios (TR) associated with TTP as derived from males' reported CD of their pregnancy attempt. The estimated prevalence of infertility was 12.0% (95% CI: 7.0, 23.2). Longer TTP was associated with older male age (35-45 vs. 17-24years) (TR: 2.49; 95% CI: 1.03, 6.03), biological childlessness (TR: 1.53; 95% CI: 1.07, 2.19) and lack of health insurance (TR: 1.73; 95% CI: 1.02, 2.94) after controlling for the differences in couples' age and other socioeconomic factors. The prevalence of infertility based on male reporting is consistent with estimates of infertility in the US found in prospective cohort studies and CD studies based on female reporting. Our findings suggest that male partners can reliably inform about couple infertility. Interventions and services aimed at reducing couple infertility should include attention to male factors associated with longer TTP identified in this study.

Prevalence of infertility in the United States as estimated by the current duration approach and a traditional constructed approach

To estimate the prevalence of infertility using a current duration approach for comparison with a traditional constructed measure. Cross-sectional survey. Not applicable. A nationally representative sample of females aged 15-44 years. None. Infertility prevalence estimated by two approaches: [1] a constructed measure derived from questions on sexual activity, contraception, relationship status, and pregnancy, and [2] a measure based on estimated time to pregnancy derived from the respondents' current duration of pregnancy attempt (i.e., current duration approach). Associations with self-reported descriptive characteristics using weighted logistic regression or parametric survival models for each respective approach. Infertility prevalence was approximately twofold higher using the current duration approach (15.5%; 95% confidence interval 8.6%-27.5%) vs. the constructed measure (7.0%; 95% confidence interval 6.2%-7.8%). Both methods identified similar patterns of increasing age, lower education, nulliparity, and history of gynecologic disorders as being associated with measures of impaired fecundity, whereas opposing patterns were seen for racial/ethnic identification and poverty status. Infertility prevalence based on a current duration approach was consistent with other US prospective cohort studies with preconception enrollment. These findings underscore the importance of definition and methodologic approach for estimating the prevalence of infertility.

The Current Duration Approach to Estimating Time to Pregnancy

Abstract. Time‐to‐pregnancy (TTP) is the duration from the time a couple starts trying to become pregnant until they succeed. It is considered one of the most direct methods to measure natural fecundity in humans. Statistical tools for designing and analysing time to pregnancy studies belong to survival analysis, but several features require special attention. Prospective designs are difficult to carry out and retrospective (pregnancy‐based) designs, being widely used in this area, do not allow efficiently including couples remaining childless. A third possible design starts from a cross‐sectional sample of couples currently trying to become pregnant, using current duration (backward recurrence time) as basis for the estimation of TTP. Regression analysis is then most conveniently carried out in the accelerated failure time model. This paper surveys some practical and technical‐statistical issues in implementing this approach in a large telephone‐based survey, the Epidemiological Observatory of Fecundity in France (Obseff).

Reply to the Comments by Drs Aalen and Hougaard on ‘The Current Duration Approach to Estimating Time to Pregnancy’ by Niels Keiding et al.

Reply to the Comments by Drs Aalen and Hougaard on ‘The Current Duration Approach to Estimating Time to Pregnancy’ by Niels Keiding <i>et al.</i>

Discussion of ‘The Current Duration Approach to Estimating Time to Pregnancy’

Discussion of ‘The Current Duration Approach to Estimating Time to Pregnancy’

Discussion of ‘The Current Duration Approach to Estimating Time to Pregnancy’

Discussion of ‘The Current Duration Approach to Estimating Time to Pregnancy’

Feasibility of the Current Duration Approach to Study the Influence of Environmental Factors on Human Fecundity

Feasibility of the Current Duration Approach to Study the Influence of Environmental Factors on Human Fecundity

Epidemiology of male reproductive function: a field searching for tools: Epidémiologie de la fonction de reproduction masculine : un champ à la recherche d’outils

An increase in the frequency of disorders of the male human reproductive organs has been described over recent decades. Neither its causes nor its consequences on fecundity, the ability of the couples to produce a live child, are clearly known. This lack of knowledge may partly be due to methodological difficulties specific to reproductive epidemiology. We discuss the relevance and limits of some markers of the male aspects of human reproduction, focusing on semen parameters and fecundability, a measure of the probability of pregnancy. Semen parameters are associated with fecundability, although they have a relatively low sensitivity to detect couples with low fecundability. The study of semen parameters proved central to describe the influence of environmental factors on the male side of reproductive function. The main limitation of semen studies is low participation rates and the possible selection biases ensuing. Fecundability can be estimated by collecting waiting time to pregnancy. Its assessment in retrospective studies often excludes the least fecund, those couples remaining childless, which entails a bias and a decrease in statistical power. The prospective approach and an approach relying on the enrollment of a cross-sectional sample of the couples currently trying to obtain a pregnancy (current duration approach) do not have these limitations. Although it has never been used, the assessment of fecundability using the current duration approach is promising both for aetiologic research and monitoring. Most of the potential markers of male reproductive function are not assessed in the general population of France, with the exception of the incidence rate of testis cancer, which is currently increasing. We present some alternatives for a monitoring system of reproductive function.