Introduction: This study investigates the association between maternal occupational pesticide exposure during the peri conceptional period and major musculoskeletal malformations in their infants. Methods: A multi-center case-control analysis was conducted using data from the National Birth Defects Prevention Study among women with due dates between October 1, 1997 and December 31, 2002. Cases included 1,041 live or still-born infants with transverse limb deficiencies, craniosynostosis, gastroschisis, or diaphragmatic hernia. Controls included 3,009 live-born infants without malformations. Self-reported maternal occupational information was used to estimate herbicide and insecticide exposure for each job held during one month pre-conception to three months post-conception. Pesticide exposure was estimated by an experienced industrial hygienist and metrics included whether any exposure occurred, exposure intensity, frequency, duration, and a cumulative index incorporating these variables for all jobs combined. To estimate peak exposure intensity and peak exposure frequency for mothers with multiple jobs, the job with the highest intensity and highest frequency, respectively, was used. Malformations with statistically significant crude associations were analyzed using logistic regression controlling for risk factors for each malformation, including infant sex, parity, maternal age, education, race/ethnicity, body mass index, folic acid use, alcohol use, and smoking. Results: Gastroschisis was associated with peak herbicide exposure frequency (adjusted odds ratio (adjusted OR): 2.80; 95% confidence interval (CI): 1.33-5.93), peak herbicide exposure intensity (adjusted OR: 2.62; 95% CI: 1.33-5.15), and the top tertile of cumulative herbicide exposure (adjusted OR: 2.31; 95% CI: 1.34-3.99), versus no exposure after controlling for gastroschisis risk factors and any insecticide exposure. Transverse limb deficiencies were significantly associated with peak herbicide exposure frequency (adjusted OR: 2.54; 95% CI: 1.06-6.08) and intensity (adjusted OR: 2.66; 95% CI: 1.22-5.81). Both gastroschisis and transverse limb deficiencies were significantly associated with peak insecticide exposure intensity after controlling for risk factors for these anomalies and any herbicide exposure. Discussion: This study employs an extensive exposure assessment methodology to estimate occupational pesticide exposure. This research suggests that gastroschisis and limb deficiencies may be associated with maternal occupational herbicide and insecticide exposure.
Women; Pregnancy; Birth-defects; Prenatal-exposure; Exposure-assessment; Pesticides; Musculoskeletal-system-disorders; Occupational-exposure; Employee-exposure; Children; Developmental-disorders; Information-retrieval-systems; Herbicides; Insecticides; Job-analysis; Mathematical-models; Statistical-analysis; Demographic-characteristics; Risk-analysis; Risk-factors