BACKGROUND:
Despite longstanding recognition of health inequities in UK maternity care, evidence remains limited on how intersecting poverty-related determinants cumulatively impact adverse perinatal outcomes at the population level. Understanding these effects is critical to inform effective, equity-focused interventions.

OBJECTIVES:
To examine structural and intermediary determinants of health and their association with adverse perinatal outcomes using linked health records in a large, diverse UK cohort.

METHODS:
We analysed 67,308 pregnancies from the Early Life Cross Linkage in Research (eLIXIR) cohort in South London using linked NHS electronic health records. Structural and intermediary poverty-related factors were assessed within a social determinants framework. Binary logistic regression with random intercepts accounted for repeated pregnancies, estimating adjusted risk ratios (aRR) for a composite adverse perinatal outcome.

RESULTS:
Women from Black (aRR 1.50), Asian (aRR 1.49), and other non-White ethnic backgrounds (aRR 1.50), those living in the most deprived areas (aRR 1.10), non-UK-born (aRR 1.20), and recent migrants (aRR 1.32) were at significantly higher risk of adverse outcomes. Intermediary factors—including lack of social support (aRR 1.21), unemployment (aRR 1.16), financial hardship (aRR 1.17), social housing (aRR 1.16), care transfers (aRR 1.27), missed appointments (aRR 1.19), and unscheduled maternity care use (aRR 1.21)—were independently associated with increased risk. Women with multiple overlapping risk factors had a significantly higher likelihood of adverse outcomes (aRR 1.23), illustrating the cumulative impact of social vulnerability.

CONCLUSIONS:
Poverty-related determinants at structural and intermediary levels substantially shape perinatal outcomes and exacerbate health inequities. Addressing these requires integrated, cross-sector strategies that extend beyond maternity services, encompassing social, economic, and housing policies to improve maternal and infant health.

KEY MESSAGE:
Addressing inequalities in perinatal outcomes requires maternity models of care addressing wider social determinants, such as continuity of care and integrated community-based services, with ongoing evaluation of interventions. Policymakers must also tackle upstream social inequalities through coordinated cross-sector efforts beyond maternity services. Poster session 4 (Group B)