Hypertensive Disorders of Pregnancy and Behavioural Outcomes in the Offspring: Findings from the Millennium Cohort Study

Background: The aim of this study was to examine the association between hypertensive disorders of pregnancy (HDP) and behavioural outcomes in offspring at five time-points. Methods: We used maternal-reported data from the Millennium Cohort Study. Data on HDP were collected when children were 9-months. Data on behavioural outcomes were collected at age 3, 5, 7, 11 and 14years using the Strengths and Difficulties Questionnaire (SDQ). Multivariate logistic regression analysis examined a HDP-behavioural difficulties relationship, using validated SDQ cut-off points. Multilevel models with linear splines examined the association between HDP and repeated measures of SDQ. Results: 18,274 singleton children were included in the study at baseline, Multivariate logistic regression suggested HDP was not significantly associated with SDQ domain cut-off points at ages 3, 7 and 11years. At age 5years, HDP was associated with a 40% increased odds of behavioural difficulties based on total SDQ(≥17) (OR:1.40, 95% CI:1.03,1.91). HDP was associated with a 43% increased odds of Peer Problem difficulties at age 5 (OR:1.43, 95% CI:1.10,1.86), and a 28% increased odds of Peer Problem difficulties(≥4) at age 14 (OR:1.28, 95% CI:1.02,1.61). In the linear spline model, mean SDQ score was higher at each time-point in those exposed to HDP, although did not always reach statistical significance. Limitations: Data on different classifications of HDP were unavailable; therefore, we could not examine the effect of gestational hypertension and preeclampsia separately. Conclusions: While we did not find strong evidence of associations between HDP and behavioural outcomes overall, some associations between HDP and behavioural difficulties did persist at age 5 and 14years.