Cerebral palsy and perinatal mortality in children born in Norway to immigrant mothers.

Abstract

Aim: To compare the prevalence and clinical characteristics of cerebral palsy (CP), and perinatal mortality, in children born to non-immigrant mothers with children born to immigrant mothers.

Method: This was a registry-based cross-sectional study. Data on children born from 2000 to 2016 were extracted from the Medical Birth Registry of Norway and linked to the Norwegian Quality and Surveillance Registry for Cerebral Palsy. The mother's country of birth was categorized into three groups: non-immigrant (born in Norway); immigrant from high-income countries (HICs); and immigrant from low- and middle-income countries (LMICs) (born abroad giving birth in Norway). Birth prevalence of CP and prevalence of perinatal mortality per 1000 live births were calculated. Odds ratios (ORs) for CP among live-born children of non-immigrant mothers compared to mothers from HICs and LMICs were calculated using logistic regression, both unadjusted and adjusted for each risk factor for CP. Pearson χ² tests were used to compare the proportions of clinical characteristics.

Results: The prevalence of CP among non-immigrant mothers was 2.11 per 1000 live births, 1.44 among mothers from HICs, and 1.71 among mothers from LMICs. The OR for CP in mothers from HICs was 0.68 and 0.81 in mothers from LMICs. Despite mothers from LMICs having higher proportions of consanguinity and lower folate intake, and their children having lower Apgar scores, the ORs for CP were unchanged after adjusting for these. Yet, children born to mothers from LMICs had higher perinatal mortality; their children with CP had higher proportions of intellectual disability.

Interpretation: The lower birth prevalence of CP among children born to mothers from LMICs was unexpected. Yet, children born to mothers from LMICs had higher perinatal mortality, which could impact the number of live-born children with CP.