Abstract
ObjectiveOver 12% of women in the United States have reduced fertility and/or fecundity. Environmental factors, such as temperature, and socioeconomic factors have been implicated in reducing female fecundity. The purpose of this study is to investigate the effect of environmental factors coupled with socioeconomic factors on birth rate at the country-level. We use birth rate as a proxy for female fecundity. This will enable us to identify the most important factors affecting female fecundity.MethodsUsing country-specific data from 182 countries, we constructed a regression model of the effects of environmental and socioeconomic factors on birth rate at the country-level. Our model assesses the role of temperature, Gross Domestic Product (GDP) per capita, fine air particulate matter (PM 2.5), and prevalence of male and female Body Mass Index (BMI) > = 25 (age-standardized) on birth rate per country. Because many of these factors are inter-dependent, we include all possible two-way interaction terms to assess the role of individual factors and interactions between multiple factors in the model.ResultsIn the full regression model, we found that GDP per capita along with 5 interaction terms were significant after adjusting for multiple testing. Female BMI was only nominally significant. GDP per capita was independently associated with birth rate (adjusted p-value <0.001). Prevalence of BMI > = 25 age-standardized in males and females were also significant when interacting with air pollution or GDP on female fecundity (birth rate). Temperature did not affect birth rate either independently or as an interaction unless BMI was removed from the model.ConclusionA country’s economic wealth was the most significant factor in predicting birth rate in a statistical model that includes environmental and socioeconomic variables. This is important for future studies investigating environmental factors involved in increasing or decreasing female fecundity.
Highlights
In the full regression model, we found that Gross Domestic Product (GDP) per capita along with 5 interaction terms were significant after adjusting for multiple testing
Prevalence of Body Mass Index (BMI) > = 25 age-standardized in males and females were significant when interacting with air pollution or GDP on female fecundity
We investigated the relationship between fecundity and two environmental factors–temperature and air pollution–and socio-economic factors–GDP, male and female BMI
Summary
Over 12% of women in the United States have reduced fertility and/or fecundity [1]. Maternal birth season plays an important role in fertility in women [2,3,4]. The main hypothesized biological mechanism underlying this relationship was that oocytes’ exposure to high temperatures at birth resulted in increased oocyte loss early in life [2, 7,8,9]. This reduction in oocyte volume thereby reduces a woman’s fertility when she goes to bear children later in life. Results from Vietnam [11] and Romania [12] appeared to find the opposite result, namely females born in high heat environments had increased fertility This reveals an incomplete understanding regarding the relationship between seasonal temperature variation and female fertility/fecundity later in life
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
