Four years after a breakthrough study raised awareness of a possible link between selenium intake and the duration of pregnancy, a multi-national study reports finding significant dose-based associations in some parts of the world, but unclear effects in others.
Selenium (Se) is a dietary trace mineral that has a number of health effects, including impacts on thyroid function, inflammation and, potentially, reducing the risk of preterm birth (PTB). The mineral is found in soils at varying concentrations worldwide, and gets absorbed through consuming certain foods including Brazil nuts, seafoods and meats.
The possibility that selenium could be a useful dietary supplement for pregnant women emerged in 2017 after experts at Cincinnati Children’s collaborated with researchers in Europe, 23andMe and the Bill and Melinda Gates Foundation on a massive genetic analysis that found several gene variants linked to the risk of preterm birth.
The new study results were published online Sept. 13, 2021 in BMJ Global Health.
Corresponding authors are Nagendra Monangi, MD, and Ge Zhang, MD, PhD, at Cincinnati Children’s and Lou Muglia, MD, PhD, formerly of Cincinnati Children’s, now president and CEO of the Burroughs Wellcome Fund. Key contributions to this study were also made by Huan Xu, PhD, Joanne Chappell and Elizabeth Belling, with testing performed in collaboration with the University of Cincinnati Department of Chemistry.
The initial NEJM study overwhelmingly involved women of European ancestry. The new study established an international consortium of existing cohorts and analyzed data from nearly 10,000 women in 17 scattered locations, including Asia and Africa. A “fixed-effect meta-analysis” across the 17 cohorts does show a significant association between selenium levels, preterm birth and gestational duration. Longer gestation was observed with each 15 ng/mL increase in selenium concentration.