Maternal Serum Metals Exposure Pattern By Metallomics Profiling and Risk of Preterm Birth in Rural Bangladesh

Background: The prevalence of preterm birth in Bangladesh is estimated to be 19·1%, the highest in the world. Although, prenatal exposure to several metals has been linked with preterm birth, fewer prospective studies have investigated multiple metals simultaneously or potential interaction between metals.Methods: This study included data from 780 mother-offspring pairs recruited in a well-established prospective birth cohort in Bangladesh. Serum concentrations of 19 metals were measured in first and second trimesters using inductively coupled plasma mass spectrometry. Logistic regression and mediation analyses were used to investigate the crucial metals and their exposure windows and interactions, as well as mediating role of the metals.Findings: Maternal exposure to zinc, arsenic, and strontium in the first trimester and exposure to barium in the second trimester were significantly associated with preterm risk. Zinc in the first trimester showed antagonistic effect against arsenic toxicity in the first (ORinteraction= 0·35; 95% CI: 0·12–0·97) and second (ORinteraction= 0·31; 95% CI: 0·11–0·90) trimesters. Furthermore, low marriage age was associated with an exponential increase in the risk of preterm, while 30.16% of its risk effect was mediated through affecting these four metal concentrations.Interpretation: Multiple maternal serum metals are individually and interactively associated with the risk of preterm during pregnancy. The findings suggest that zinc supplementation at early pregnancy might attenuate the risk of preterm attributed to prenatal arsenic exposure.Funding: Funding of China Ministry of Science and Technology and the U.S. National Institutes of Health.Declaration of Interest: All authors declare no competing interestsEthical Approval: All protocols were reviewed and approved by the Human Research Committees at Harvard T.H. Chan School of Public Health, Nanjing Medical University, and Dhaka Community Hospital Trust.