Title: A Comprehensive Assessment of the Associations Between Season of Conception and Birth Defects, Texas, 1999-2015.

Authors: Benavides, Elisa; Lupo, Philip J; Langlois, Peter H; Schraw, Jeremy M

Published In Int J Environ Res Public Health, (2020 Sep 29)

Abstract: Birth defects prevalence may vary seasonally, but previous studies have focused on a few commonly occurring phenotypes. We performed a phenome-wide association study (PheWAS) in order to evaluate the associations between season of conception and a broad range of birth defects. Date of conception was estimated for all livebirths and birth defect cases in Texas from 1999-2015 using data from vital records, provided by the Texas Department of State Health Services Center for Health Statistics. Birth defects diagnoses were obtained from the Texas Birth Defects Registry, a statewide, active surveillance system. We estimated prevalence ratios (PRs) for phenotypes with ≥50 cases according to conception in spring (March-May), summer (June-August) or fall (September-November) relative to winter (December-February), using Poisson regression. Season of conception was associated with 5% of birth defects studied in models adjusted for maternal age, education, race/ethnicity, and number of previous livebirths. Specifically, summer conception was associated with any monitored birth defect (PR 1.03, 95% CI 1.02-1.04) and five specific phenotypes, most notably Hirschsprung disease (PR 1.46, 95% CI 1.22-1.75). These findings suggest that seasonally variable exposures influence the development of several birth defects and may assist in identifying novel environmental risk factors.

PubMed ID: 33003294

MeSH Terms: Adolescent; Adult; Child; Congenital Abnormalities/epidemiology*; Female; Fertilization/physiology*; Humans; Infant, Newborn; Maternal Age; Pregnancy; Prevalence; Seasons*; Texas/epidemiology; United States/epidemiology; Young Adult