Violence during pregnancy and newborn outcomes: a cohort study in a disadvantaged population in Brazil.

Background: Violence against pregnant women is an increasing public health concern. The purpose of this study is to estimate the prevalence of violence during pregnancy, to identify characteristics associated and to assess the impact of violence on newborn outcomes.
Methods: Prospective cohort study of 652 pregnant women attending primary care clinics in Southern Brazil, from June 2006 to September 2007. Women with gestational age ranging from 16th and 36th were enrolled and their exposure to violence and mental disorder was assessed. After the birth they were contacted by telephone when information on obstetric and neonatal outcomes was obtained.
Results: Any violence during current pregnancy was reported by 18.3% [95% confidence interval (CI) 15.3-21.4%] participants, 15.0% (95% CI 12.3-17.8%) psychological violence, 6% (95% CI 4.2-7.8%) physical violence and 3% (0-0.5%) sexual violence. These women were more often of low income, did not work or study and had inadequate prenatal care and pregnancy weight gain. There was a statistically significant crude association between exposure to physical and psychological violence [relative risk (RR) 3.21 (1.51-6.80)]. After adjustment for family income, number of prenatal visits, length of gestation and gestational weight gain, the effect size decreased, but remained statistically significant (RR 2.18; 95% CI 1.16-4.08%).
Conclusion: In disadvantaged settings in Brazil, violence in pregnancy is frequent; it is associated with inadequate maternal weight gain during pregnancy and prenatal care, and increases risk of low birth-weight. Thus, violence in pregnancy imposes a challenge to effective prenatal care delivery with potential benefits to the mother and her baby.