This study examined the association between exposure to occupational hazards and pregnancy outcomes using data from a case-control study conducted in 29 hospitals in Shanghai, China. The sample included 1,875 perinatal deaths and newborns with birth defects and the same number of controls. Information on mother's exposure to occupational radiation, chemicals, noise, and pesticides was investigated. Logistic regression analysis controlling for potential confounders showed that exposure to radiation before/during pregnancy was associated with antepartum fetal death, birth defects, small-for-gestational-age (SGA), and threatened abortion. Exposure to chemicals before/during pregnancy was associated with antepartum fetal death, early neonatal death, birth defects, preterm birth, and threatened abortion. Women exposed to pesticides during pregnancy had an increased risk of SGA and threatened abortion. Exposure to occupational noise during pregnancy increased the risk of antepartum fetal death. Furthermore, higher than expected numbers of congenital anomalies in the central nervous system (CNS) were identified among women exposed to chemicals before pregnancy and to pesticides during the first trimester of pregnancy. No significant association was found between occupational exposure and intrapartum fetal death. Although recall bias may be possible in our study, the findings encourage further research.
PIP: Epidemiologist analyzed October 1986-September 1987 data on 1875 perinatal deaths and newborns with defects and the same number of controls from 29 hospitals in Shanghai, China, to determine the association between occupational exposure to radiation, chemicals, pesticides, and noise and congenital abnormalities, perinatal death, small for gestational age (SGA), preterm birth, and threatened abortion. They found much higher than expected numbers of central nervous system birth defects and significantly lower than expected numbers of other birth defects among women exposed to chemicals (p .1 and p .05, respectively). They uncovered higher than expected numbers of urogenital system birth defects and other birth defects among women exposed to occupational noise during the 1st trimester of pregnancy (p .01 and p .05, respectively). There were very much higher than expected numbers of central nervous system effects among women exposed to pesticides during the 1st trimester of pregnancy (p .01). None of the hazards was associated with intrapartum fetal death. Exposure to radiation before and during pregnancy was positively related with antepartum fetal death (odds ratio [OR] = 1.7 and 2.4 respectively), birth defects (OR = 1.9 both before and during), SGA (OR = 2.7 and 2.2, respectively), and threatened abortion (OR = 2.1 and 3.2). Chemical exposure before and during pregnancy had an increased risk for antepartum fetal death (OR = 2.9 and 3.5, respectively), early neonatal mortality (OR = 1.7 and 2.2, respectively), birth defects (OR = 1.7 and 3.5, respectively), preterm birth (OR = 1.2 and 1.4, respectively), and threatened abortion (OR = 1.5 and 1.3, respectively). Pesticide exposure during pregnancy was associated with SGA (PR + 2.9) and threatened abortion (OR = 3.9). Noise exposure during pregnancy was related with antepartum fetal death (OR = 1.9). Even though recall bias may have been a factor in this study, these results did suggest additional research.