Intimate partner violence (IPV) is a public health problem that affects millions of women worldwide and can occur during both pregnancy and the perinatal period. We aimed to evaluate if the experience of psychological and physical intimate partner violence (IPV) adversely affects pregnancy outcomes. We established a cohort of 779 consecutive mothers receiving antenatal care including ultrasound and giving birth in 15 public hospitals, drawn using cluster sampling of all obstetric services in Andalusia, Spain (February-June 2010). Trained midwives gathered IPV data using the Index of Spouse Abuse validated in the Spanish language (score ranges: 0-100, higher scores reflect more severe IPV; cut-offs: physical IPV = 10, psychological IPV = 25). Socio-demographic data, including lack of kin support, maternal outcomes, and hospitalization were collected. Multivariate logistic regression estimated adjusted odds ratios (AOR), with 95% confidence intervals (CI), of the relationship between psychological and physical IPV and maternal outcomes, controlling for socio-demographic characteristics. Response rate was 92.2%. Psychological IPV, reported by 21.0% (n = 151), was associated significantly with urinary tract infection (127 (23%) vs 56 (37%); AOR = 1.9; 95%CI = 1.2-3.0), vaginal infection (30 (5%) vs 20 (13%); AOR = 2.4; 95%CI = 1.2-4.7) and spontaneous preterm labour (32 (6%) vs 19 (13%); AOR = 2.2; 95%CI = 1.1-4.5). Physical IPV, reported by 3.6% (n = 26), was associated with antenatal hospitalizations (134 (19%) vs 11 (42%); AOR = 2.6; 95%CI = 1.0-7.1). Lack of kin support was associated with spontaneous preterm labour (AOR = 4.7; 95%CI = 1.7-12.8). Mothers with IPV have higher odds of complications. Obstetricians, gynaecologists and midwives should act as active screeners, particularly of the undervalued psychological IPV, to reduce or remedy its effects.