Employment and low birth weight in black women

Recent studies have not shown adverse effects of employment during pregnancy on the pregnancy outcome, but most have not successfully distinguished factors due to work-related physical and mental strain from differences in social, economic and cultural characteristics between employed and non-employed women. We analyzed data from the Alameda County Case-Control Study of Low Birth Weight to address the question of employment as a risk factor for low birth weight in more depth. Subjects in the study were singleton infants without congenital malformations born in 1987 to black or white, non-hispanic residents of Alameda County, a large urban community in California. Cases were all infants weighing less than 2500 g at birth; controls were chosen at random from the infants weighing 3000 g or more. The mothers of 377 black cases, 389 black controls, 233 white cases and 239 white controls could be located and interviewed. This analysis excluded the white women because evidence of response bias in regard to employment was found for them but not for black women. The percentage of black women in the study who were employed during pregnancy was 49.9%. Employment was associated with a significantly lower relative risk of low birth weight before and after controlling for age, parity, smoking, heavy alcohol use, prior low birth weight infants and low pre-pregnancy weight. After adjustment for known risk factors for low birth weight, employment explained more of the variance of low birth weight than other commonly used measures of 'social class', including income, education and marital status.(ABSTRACT TRUNCATED AT 250 WORDS)