Proximity to major roadways and prospectively-measured time-to-pregnancy and infertility

Abstract

We aimed to study the potential impact of proximity to major roadways on time-to-pregnancy and infertility in couples attempting pregnancy in the Longitudinal Investigation of Fertility and Environment (LIFE) study (2005-2009), a population-based, prospective cohort study. Couples attempting pregnancy (n=500) were enrolled and followed prospectively until pregnancy or 12 months of trying and 393 couples (78%) had complete data and full follow-up. Time-to-pregnancy was based on a standard protocol using fertility monitors, tracking estrone-3-glucuonide and luteinizing hormone, and pregnancy test kits to detect human chorionic gonadotropin (hCG). The fecundability odds ratio (FOR) and 95% confidence interval (CI) were estimated using proportional odds models. Infertility was defined as 12 months of trying to conceive without an hCG pregnancy and the relative risk (RR) and 95% CI were estimated with log-binomial regression. Final models were adjusted for age, parity, study site, and salivary alpha-amylase, a stress marker. Infertile couples (53/393; 14%) tended to live closer to major roadways on average than fertile couples (689 m vs. 843 m, respectively) but the difference was not statistically significant. The likelihood of pregnancy was increased 3% for every 200 meters further away the couples residence was from a major roadway (FOR=1.03; CI=1.01-1.06). Infertility also appeared elevated at moderate distances compared to 1000 meters or greater, but estimates lacked precision. Our findings suggest that proximity to major roadways may be related to reductions in fecundity. Prospective data from larger populations is warranted to corroborate these findings.

Residential proximity to major roadways and traffic in relation to outcomes of in vitro fertilization

“…As the number of couples seeking medical treatment for infertility continues to rise (Kushnir et al 2017), a better understanding of how environmental factors impact outcomes of IVF remains an important health issue particularly given the high costs and psychological toll of having to undergo multiple IVF treatments (Brandes et al 2009; Katz et al 2011). Our research not only corroborates evidence from studies among women attempting to conceive naturally (Mahalingaiah et al 2016; Mendola et al 2017) and through assisted reproduction (Legro et al 2010), it further highlights that exposure to traffic-related air pollution may have an effect on early implantation failure. More research is needed to evaluate which specific traffic-related air pollutant(s) may be responsible for this association and whether there is a specific window of heightened susceptibility to its adverse effects.…”

“…Among women in the Nurses’ Health Study II, those who lived within 200 m of a major roadway had 1.11 (95% CI 1.02–1.20) times the risk of self-reported infertility compared to women living ≥200 m away (Mahalingaiah et al 2016). Among couples in the Longitudinal Investigation of Fertility and the Environment (LIFE) Study, the likelihood of pregnancy was increased 3% for every 200 m further away the couples’ residence was from a major roadway (Mendola et al 2017). Regarding specific air pollutants and spontaneous fertility, a cross-sectional study found that the number of live births per 1000 women between the ages of 15 and 44 years was significantly lower in census tracts with higher exposure to NO x , nitrogen dioxide (NO 2 ), fine particular matter (PM 2.5 ), and course particulate matter (PM 10 ) (Nieuwenhuijsen et al 2014).…”

Time-Varying Exposure to Air Pollution and Outcomes of in Vitro Fertilization among Couples from a Fertility Clinic

“…Among women attempting to conceive without medical assistance, those residing closer to major roadways were shown to have a higher risk of infertility (Mahalingaiah et al. 2016) and longer time to pregnancy (Mendola et al. 2017), and those with higher exposure to NO2, PM2.5, and PM10 had lower census tract–level fertility rates (Nieuwenhuijsen et al.…”

Increase in fertility following coal and oil power plant retirements in California

“…Self-reported data indicated that ovulatory disorder and male infertility may have driven these associations [ 11 ]. In Texas and Michigan, among 393 couples attempting to conceive, couples were 3% more likely to become pregnant for each additional 200 m they lived away from a major roadway [ 12 ]. These changes in fertility may result from endocrine disruption, oxidative stress, or DNA modifications caused by pollutants [ 10 ].…”