Associations of Glyphosate Exposure in Pregnancy with Preterm Birth: a Longitudinal Birth Cohort Study.
BACKGROUND Emerging data suggests that glyphosate, a non-selective herbicide, can influence reproductive health. We investigated associations of prenatal exposure to glyphosate and aminomethylphosphonic acid (AMPA), with preterm birth and its subtypes. METHODS We used data from the NYU Children's Health and Environmental Study, a prospective birth cohort in New York City (2016-2019). Participants (n=1450) provided urine samples at 4 to <18 weeks and 18 to 25 weeks gestation. Exposure was adjusted for creatinine and natural log transformed. Preterm birth was defined as a birth occurring before 37 weeks of gestation. We also explored preterm birth subtypes, spontaneous preterm births and medically indicated preterm births as secondary outcomes. To examine associations between glyphosate and AMPA at both timepoints with preterm birth, we used generalized estimating equations with a logit link function. RESULTS Overall, 7% (n=103) of births were preterm. Glyphosate concentrations at 18-25 weeks was associated with preterm birth (OR: 1.35, 95% CI: 1.04, 1.76) and spontaneous preterm birth (OR: 2.01, 95% CI: 1.40, 2.90). AMPA was not associated with preterm birth in any model. CONCLUSIONS These results support evidence that glyphosate may act upon pathways leading to preterm birth and spontaneous preterm birth. Our study highlights pregnancy as a vulnerable period to glyphosate exposure.