O125. Ethnicity: An independent risk factor for adverse perinatal outcome in women with chronic hypertension

Abstract

Introduction Ethnic variation in incidence of adverse perinatal outcomes has been previously described, but similar data from pregnancies exclusively in women with chronic hypertension are limited. Objectives To perform a retrospective cohort study of pregnant women with chronic hypertension to assess the impact of ethnicity as an independent risk factor on adverse perinatal outcome. Method Demographic and delivery data of women with chronic hypertension and singleton pregnancies from two tertiary obstetric units between 2000 and 2015 were extracted from maternity databases. Women were allocated to one of four groups of ethnicity (aligned to those used by the UK Office for National Statistics) for analysis: White, Black, Asian and other. Risk ratios and risk differences were calculated by generalised linear models, with a log or linear link respectively, together with risk ratios adjusted for baseline characteristics (maternal age, parity, body mass index, smoking); the statistical package Stata version 1.3 (StataCorp, College Station, Texas) was used. Results 4713 singleton pregnancies in women with chronic hypertension were included. All adverse perinatal outcomes occurred more frequently in Black women compared to White women (Table, showing percentages and adjusted risk ratios with 95% confidence intervals using White women as the referent category). Asian women also were at increased risk, though to a lesser extent. Download : Download full-size image Conclusion Black women with chronic hypertension are at markedly increased risk of many adverse perinatal outcomes compared to White women, with features of placental disease. Further research is needed to explore the pathophysiology underpinning these disparities in outcome. Ethnic differences in incidence of chronic hypertension and response to antihypertensive agents in non-pregnant individuals exist. Antihypertensive treatments prescribed in pregnancy may need to account for ethnic variation in response to therapy and an awareness of these potential differences should inform stratification of antenatal care pathways.