Impact of intimate partner violence, mental ill-health and risk of small vulnerable newborn births: a maternity population-based data linkage study

Objective: Estimate the risk of small vulnerable newborn birth (SVN) from intimate partner violence (IPV) experience Design: Maternity population-based administrative data-linkage cohort study Setting: Births in maternity services in Northern Ireland Population: Women with singleton pregnancy, with liveborn or stillborn infants born 24-42 weeks’ gestation, with an estimated pregnancy start date January 2011 to December 2021. Methods: : Pregnancy records were linked to community-dispensed prescriptions and hospital diagnoses data. Research ready data was provided by the HSC Honest Broker Service; IPV, maternal characteristics, and SVN (preterm, small for gestational age, low birthweight) were ascertained through maternity records. Mental health conditions were ascertained via medications or ICD-10 hospital diagnosis codes. Modified Poisson regression was used to examine the likelihood of SVN given exposure to IPV, adjusted for mental ill-health and additional maternal characteristics. Main Outcome Measures: Risk ratios (RR) and 95% confidence intervals (CI) for SVN. Results: : From 248,645 eligible pregnancies, 11,388 (4.6%) women disclosed IPV (active: n=3,713, 1.5%; historical: n=7,675, 3.1%). The group with highest prevalence of IPV were pregnant teenagers (n=995, 12.2%). Risk of SVN was increased for women reporting both active IPV (RR=1.20, 95%CI:1.12-1.28) and historical IPV (RR=1.18, 95%CI:1.12-1.24) independent of the number of coexisting mental health conditions and other maternal characteristics. Conclusions: : IPV, both active and historical, is associated with an increased risk of birth of babies who are small and vulnerable. Clinical risk models for SVN may be improved by considering IPV experience, even historical. Funding: UKRI’s ADRC NI (ES/W010240/1); Keywords: Intimate partner violence; small vulnerable newborn