Lisa M. Pastore

Risk of stillbirth from occupational and residential exposures.

OBJECTIVES: 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.

Predictors of urinary tract infection at the first prenatal visit.

We identified maternal demographic, behavioral, and medical history factors that predict bacteriuria (that is, symptomatic and asymptomatic urinary tract infection) at prenatal care initiation. We applied logistic regression modeling to data from all prenatal care recipients who delivered during 1990-1993 and resided in selected North Carolina counties (N = 8037), omitting those with diabetes mellitus, human immunodeficiency virus, or structural urologic abnormalities. The two strongest predictors of bacteriuria at prenatal care initiation were an antepartum urinary tract infection prior to prenatal care initiation (for whites, adjusted prevalence odds ratio (POR) = 2.5, 95% CI 0.6-9.8; for blacks, POR = 8.8, 95% CI 3.8-20.3) and a pre-pregnancy history of urinary tract infection (POR = 2.1, 95% CI 1.4-3.2). For white women only, education beyond high school and age > or =30 years were inversely associated (POR < or = 0.6). Sickle cell hemoglobin nearly doubled the prevalence odds for bacteriuria among African-Americans (POR = 1.9, 95% CI 1.0-3.5), whereas African-Americans with normal hemoglobin had reduced prevalence odds compared with whites (POR = 0.6, 95% CI 0.4-0.9). This study suggests predictors not considered before, including race controlling for sickle cell disease or trait and antepartum urinary tract infections prior to prenatal care.Herbicides, chlorophenols, and other occupational exposures are suspected risk factors for soft-tissue sarcoma, but the epidemiologic evidence is inconsistent. Given that soft-tissue sarcomas represent a heterogeneous mix of cancer subtypes and that these subtypes have different disease patterns by race, sex, and age at diagnosis, studying all soft-tissue sarcomas combined may mask subtype-specific associations. Using the Selected Cancers Study, a large population-based case-control study of sarcoma conducted among U.S. men aged 30 to 60 in 1984 to 1988, we explored the occupational risk factors for soft-tissue sarcoma subtypes and skeletal sarcoma. The analysis included 251 living sarcoma cases (48 dermatofibrosarcoma protuberans, 32 malignant fibrohistiocytic sarcoma, 67 leiomyosarcoma, 53 liposarcoma, and 51 skeletal sarcoma) and 1908 living controls. Exact conditional logistic regression models suggested patterns of subtype specificity for occupational exposures. Self-reported herbicide use was associated with malignant fibrohistiocytic sarcoma (OR = 2.9, 95% CI = 1.1-7.3). We found elevated risks for chlorophenol exposure and cutting oil exposure and malignant fibrohistiocytic sarcoma and leiomyosarcoma. We found no occupational risk factor for liposarcoma. Polytomous regression models identified different odds ratios across subtypes for plywood exposure and exposure to wood and saw dust. Although exploratory, this analysis suggests that occupational risk factors for sarcoma are not uniform across subtypes.

Predictors of symptomatic urinary tract infection after 20 weeks' gestation

OBJECTIVE:To identify predictors of symptomatic urinary tract infection (UTI) after 20 weeks’ gestation.STUDY DESIGN:A retrospective cohort analysis was conducted of all deliveries at three North Carolina hospitals between 1990 and 1993. A total of 7403 deliveries remained after exclusions (pre-pregnancy diabetes, HIV-positive, structural urologic abnormalities, no prenatal care) and restrictions (black or white race, county of residence). Cystitis and pyelonephritis were identified by clinician diagnosis. Multiple logistic regression was conducted.RESULTS:Prior UTIs (both before and earlier in pregnancy), nonprivate clinics, and a history of chlamydia (white women only) doubled the risk of symptomatic UTIs after 20 weeks’ gestation. The strongest predictor of pyelonephritis was prior antenatal UTIs (adjusted incidence odds ratio = 5.3, 95% confidence interval of 2.6–11.0), followed by less education (<12 years), a history of chlamydia, nonprivate clinics, illicit drug use, sickle cell hemoglobinopathy, and being unmarried.CONCLUSION: Medical history and demographic factors predict cystitis and pyelonephritis after 20 weeks’ gestation. Prospective studies of pyelonephritis predictors and screening strategies are warranted.