Psychological intimate partner violence (IPV), a global public health problem, afects mothers
during pregnancy. We evaluated its relationship with preterm birth. We established a cohort of 779
consecutive mothers receiving antenatal care and giving birth in 15 public hospitals in Spain. Trained
midwives collected IPV data using the Index of Spouse Abuse validated in the Spanish language.
Preterm was defned as birth before 37 completed weeks of gestation. Gestational age was estimated
by early ultrasound. With multivariate logistic regression we estimated the relative association of IPV
with preterm birth as adjusted odds ratios (AOR), with 95% confdence intervals (CI). In propensity
score analysis, using weighting by inverse probability of exposure to IPV, the whole sample was used
for estimating the absolute diference in probability of preterm amongst ofspring born to mothers
with and without IPV. Socio-demographic and other pregnancy characteristics served as covariates
in both analyses. Preterm occurred in 57 (7.3%) pregnancies. Psychological IPV, experienced by
151 (21%) mothers, was associated with preterm birth (11.9% vs 6.5%; AOR= 2.4; 95% CI = 1.1–5.0;
p = 0.01). The absolute preterm diference in psychological IPV compared to normal was 0.08 (95%
CI = 0.01–0.16; p = 0.04). The probability of preterm birth was 8% higher on average in women with
psychological IPV during pregnancy. As our analysis controlled for selection bias, our fndings give
credence to a causal inference. Screening and management for psychological IPV during pregnancy is
an important step in antenatal care to prevent preterm birth.
