Parental occupation and birth outcome in an agricultural community

The general birth outcome and prevalence of specific birth defects was investigated within an agricultural community through the review of birth records in a major hospital in Imperial County, California. Of all singleton births (N = 2 463) occurring within a four-year period, 990 or 40.2% involved offspring with one or both parent(s) who were agricultural workers. The progeny of agricultural and nonagricultural workers were similar with regard to sex ratios, prevalence of low birth-weight infants, stillbirth rate, minor and major malformation rates, and prevalence of neonatal deaths. Limb reduction defects, however, occurred more frequently among offspring of agricultural workers (5.05 per 1 000 total births versus 2.19 per 1 000 total births, rate ratio = 2.3). Furthermore, the prevalence of limb reduction defects among agricultural workers was 3- to 14-fold higher than available United States rates (0.36-1.65 per 1 000 total births). Findings from our study suggest that agricultural communities and, in particular, agricultural workers may be at excess risk of producing a child with a limb reduction defect.