236: Hypoxic ischemic encephalopathy in the offspring of immigrant women in Sweden: a cohort study

Abstract

One out of four women giving birth in Sweden are foreign born. Immigrant status has been associated with adverse perinatal outcomes. The aim of this study was to investigate the risk of neonatal hypoxic ischemic encephalopathy (HIE) in the offspring of foreign-born mothers, compared to the offspring of native Swedish women. A national population-based cohort study of 621,397 non-malformed live singleton births at gestational week 36 and beyond in Sweden, from January 1, 2009 to December 31, 2015. The main exposure was maternal country of birth. 180 countries were represented and divided into seven sub-groups according to geographic area; Sweden (reference), Western Countries, Eastern Europe, sub-Saharan Africa, the Middle East and north Africa, Asia and South and Central America. The main outcome was neonatal HIE (ICD-10 code: P91.6). Odds ratios (OR) with 95% confidence interval (CI) were calculated. In total 799 (1.3 per 1000) infants were diagnosed with neonatal HIE. Offspring of mothers born in sub-Saharan Africa had the highest incidence of neonatal HIE (2.3 per 1000). Compared to neonates born by native Swedish women, neonates to mothers born in sub-Saharan Africa had an almost two-folded increased risk of HIE (OR 1.8; 1.4-2.5). After adjustment for gestational age, maternal age, parity, height, BMI, cohabitation, smoking, employment status, hypertensive disorders and diabetes mellitus the risk was only slightly attenuated (aOR 1.5; 1.1-2.2). Offspring in other sub-groups had no increased risk compared to the reference. The offspring of women born in sub-Saharan Africa are at increased risk of neonatal HIE compared to the offspring of native Swedish women. This is of concern due to the potential associated long-term neurologic morbidity. The reasons need to be investigated in future studies.