Physical partner abuse during pregnancy: a risk factor for low birth weight in Nicaragua.

To assess whether being physically abused during pregnancy increases the risk of a low birth weight (LBW) infant. We conducted a hospital-based case-control study in León, Nicaragua. Cases consisted of 101 newborns with a birth weight under 2500 g, and for each case two controls with a birth weight over 2500 g were selected randomly from infants born the same day. Anthropometry of newborns was done immediately after birth, and background information and data on experiences of violence and potential confounders were obtained through private interviews with mothers. Crude and adjusted odds ratios (ORs) and population-attributable proportion were calculated for exposure to partner abuse in relation to LBW. Multivariate logistic regression analysis was used to control for potential confounding. Seventy-five percent of LBW newborns (cases) were small for gestational age and 40% were preterm. Twenty-two percent of the mothers of LBW infants had experienced physical abuse during pregnancy by their intimate partners compared with 5% of controls. Low birth weight was associated with physical partner abuse even after adjustment for age, parity, smoking, and socioeconomic status (OR 3.9; 95% confidence interval 1.7, 9.3). Given a causal interpretation of the association, about 16% of the LBW in the infant population could be attributed to physical abuse by a partner in pregnancy. Physical abuse by a partner during pregnancy is an independent risk factor for LBW.