County-level pesticide use and risk of shortened gestation and preterm birth

Abstract

Aim: This study assesses the association between pesticide exposure in pregnancy, preterm birth (PTB) and shortened gestation.

Methods: Pregnancy information was abstracted from the Centers for Disease Control (CDC) Non-Public Use Natality Datasets 1990-2005. Pesticide use in maternal county of residence was calculated using California Pesticide Use Reporting (PUR) data 1990-2005. Counties were ranked by pesticide use, and birth months were sorted by peak (May-June) or nonpeak (other months) pesticide use. Multivariate logistical regression models were used.

Results: Counties with higher pesticide use were associated with higher PTB (low 8.59 ± 0.11%, moderate 9.25 ± 0.07%, high 10.0 ± 0.06%, p's < 0.001) and shorter gestations (low 39.197 ± 0.014 weeks, moderate 39.126 ± 0.011 weeks, high 39.049 ± 0.011 weeks, p's < 0.001). Peak pesticide months were associated with higher PTB (10.01 ± 0.05% vs. 9.36 ± 0.05%, p < 0.001) and shorter gestations (39.069 ± 0.007 weeks vs. 39.122 ± 0.007 weeks, p < 0.001). The pesticide effect on shortened gestation and higher PTB was found in all racial groups. Pesticide use was highest for fungicides > insecticides > fumigants > herbicides > others. Each pesticide type was found to be associated with higher PTB and shorter gestation.

Conclusion: PTB and shortened gestation were significantly associated with pesticide use in maternal county of residence regardless of race, gestation at birth, and in most risk categories.

Keywords: Gestation; Pesticide; Pregnancy; Preterm birth.