25 Effect of access to antenatal care on risk of preterm birth among migrant women in Italy: a population-based cohort study

Abstract OP 32: Health Status 1, B210 (FCSH), September 5, 2025, 09:00 - 10:00 Objective To assess the association between maternal migration status and preterm birth, and whether better access to and utilisation of antenatal care in pregnancy mitigates the risk of preterm birth. Design Population-based cohort. Setting Health management information system of the Lombardy region, Italy. Population: First singleton births of women aged 15–55 years at 22-42 gestational weeks, between 2016 and 2021. Methods Assessed the risk of preterm birth (<37 weeks). Main outcome measures A multivariable logistic regression mediation model calculated the mediation effect of access to and utilsation of antenatal care in the association between maternal migrant status and preterm birth, as well as the residual effect not mediated by it. Analyses were adjusted for the socio-demographic and pregnant characteristics of the women. Results Of 349,753 births in the cohort, Italian nationality accounted for 71 %; 28.4 % were documented migrants and 0.4 % undocumented migrants. Among them, 5.3 %, 6.4 %, and 9.3 % had a preterm birth, respectively. Using deliveries of Italian citizens as referent, migrants had a significantly increased risk of preterm birth (adjusted relative risk: 1.22, 95 % confidence interval: 1.18–1.27). Access to and utilisation of antenatal care mediated 62 % of such risk. We calculated that optimal access to and utilisation of antenatal care could lead to a 37 % reduction in preterm birth risk. Conclusion Part of the excess of preterm birth among documented and undocumented migrants in Italy can be explained by sub-optimal access to and utilisation of antenatal care through the National Health Services. Improving access to/utilisation of antenatal care among all pregnant women would reduce the risk of preterm birth by about one-third.