Risk of stillbirth from occupational and residential exposures.
OBJECTIVE
To analyse the risk of stillbirth from 12 residential and occupational maternal exposures during pregnancy.


METHODS
Stillbirths and neonatal deaths in 1984 within 24 hours of birth from 10 California counties were identified from death certificates. Controls were randomly selected from live births born in 1984 and frequency matched to cases by maternal age and county. Data sources included vital statistics and a self-administered postal questionnaire. Logistic regression and proportional hazards modelling were performed; the proportional hazards considered the truncated opportunity for exposure among cases. Special focus was given to two cause of deaths groups: congenital anomalies (12% of deaths) and complications of the placenta, cord, and membranes (37% of deaths).


RESULTS
Occupational exposure to pesticides during the first two months of gestation was positively associated with stillbirths due to congenital anomalies (odds ratio (OR) 2.4, 95% confidence interval (95% CI) 1.0 to 5.9), and during the first and second trimesters with stillbirths due to all causes of death (risk ratios (RR) 1.3-1.4, 95% CI 1.0 to 1.7) and stillbirths due to complications of the placenta, cord, and membranes (RR 1.6-1.7, 95% CI 1.1 to 2.3). Occupational exposure to video display terminals in the third trimester was found to have a modest inverse association with stillbirths (RR 0.7, 95% CI 0.6, 0.9). Home pesticide exposure was positively associated with stillbirths due to congenital anomalies (OR 1.7, 95% CI 1.0 to 2.9).


CONCLUSIONS
Occupational exposure to pesticides, especially during early pregnancy, had a clear positive association with stillbirths regardless of cause of death. Methodologically, this study of stillbirths is unique in its analysis of specific causes of death and use of time specific exposure windows.
Pastore
L M
LM
Department of Epidemiology, School of Public Health, University of North Carolina, Chapel Hill 27599, USA.
Hertz-Picciotto
I
I
Beaumont
J J
JJ
D000293:Adolescent; D000328:Adult; D002140:California / Q000453:epidemiology; D016022:Case-Control Studies; D003644:Death Certificates; D005260:Female; D005313:Fetal Death / Q000453:epidemiology* / Q000209:etiology; D006801:Humans; D007306:Insecticides / Q000009:adverse effects; D018811:Maternal Exposure / Q000009:adverse effects*; D016273:Occupational Exposure / Q000009:adverse effects*; D011247:Pregnancy; D016016:Proportional Hazards Models
D007306:Insecticides