Maternal and offspring outcomes in women with intellectual and developmental disabilities: a population-based cohort study

Objective — To compare the risks for adverse maternal and offspring outcomes in women with and without intellectual and developmental disabilities.

Design — Population-based cohort study.

Setting — Ontario, Canada.

Population — Singleton obstetrical deliveries to 18- to 49-year-old women with and without intellectual and developmental disabilities (N=3,932 in the exposed cohort, N=382,774 in the unexposed cohort; 2002-2011 fiscal years).

Methods — Women with intellectual and developmental disabilities were identified based on diagnoses in health administrative data or receipt of disability income support.The unexposed cohort comprised women without intellectual and developmental disabilities. Modified Poisson regression was used to compute adjusted relative risks (aRR) and 95% confidence intervals (CI) comparing the two cohorts.

Main outcome measures — Primary maternal outcomes were: gestational diabetes, gestational hypertension, preeclampsia, eclampsia, and venous thromboembolism. Primary offspring outcomes were: preterm birth, small for gestational age, and large for gestational age.

Results — The exposed cohort, compared to the unexposed cohort, had increased risks for preeclampsia (aRR 1.47, 95% CI 1.11-1.93) and venous thromboembolism (aRR 1.60, 95% CI 1.17-2.19). Their offspring had increased risks for preterm birth (aRR 1.63, 95% CI 1.47-1.80) and small for gestational age (aRR 1.35, 95% CI 1.25-1.45).

Conclusions — These findings suggest that there is a need to address modifiable risk factors for adverse outcomes among women with intellectual and developmental disabilities prior to and during pregnancy. Moreover, there is a need to enhance monitoring for maternal and offspring complications in this population.