Low birth weight and household structure.

Data collected during postnatal visits were used to study the risk of low birth weight (LBW) among unmarried women living alone and among unmarried women living with a partner or another adult, using married women living with their husbands as the reference group. Information on 1,627 singleton live births was included in a binomial regression, controlling for seven potential confounding variables: mother's age, education, gestational weight gain, parity, smoking status, and presence of medical problems preceding or during pregnancy. Unmarried women living alone were at greater risk of bearing a LBW infant than married women living with their husbands (RR = 2.0, 95% Cl = 1.2-3.4). Unmarried women living with a partner had a slightly lower risk of LBW than married women (RR = 0.6, 95% Cl = 0.3-1.3) and unmarried women living with another adult had a slightly increased risk (RR = 1.3, 95% Cl = 0.6-3.0), although neither of these results was statistically significant. On the basis of these findings, we suggest that public health interventions should target women according to their household structure rather than their marital status.