Evaluating the relationship between fetal aneuploidy, severe maternal morbidity, and hypertensive disorders of pregnancy: an NIS database analysis

Prior studies of pregnancies complicated by fetal aneuploidy (FA) have focused primarily on fetal and neonatal outcomes, with limited data on maternal outcomes. The relationship between FA and the risk of severe maternal morbidity (SMM) and hypertensive disorders of pregnancy (HDP) remains unclear. Clarifying these associations may inform risk stratification and counseling for patients with FA pregnancies. We aimed to assess whether FA is independently associated with increased SMM and HDP compared with non-aneuploid pregnancies after adjustment for maternal age and comorbidity burden. This cross-sectional study used the United States National Inpatient Sample to identify delivery admissions from 2016–2022. Pregnancies with FA were identified using ICD-10 codes (O35.1*) capturing trisomy 21, 18, and 13, and compared with non-FA pregnancies. SMM was defined using Centers for Disease Control and Prevention indicators. A total comorbidity index (TCI) was applied. Bivariate analyses assessed associations between FA, SMM, and HDP. Multivariable survey-weighted logistic regression models evaluated FA with SMM, HDP, and preeclampsia with severe features, adjusting for maternal age and TCI without HDP indicators. Of 5,027,079 deliveries included in the unweighted analytic sample, 6144 involved FA. SMM was similar between groups (2.2% vs 1.9%, p = 0.070). HDP was more common with FA (14.8% vs 12.9%, p < 0.001). In survey-weighted adjusted models, FA was not associated with SMM (OR 0.900, 95% CI 0.756–1.073) or HDP (OR 1.022, 95% CI 0.950–1.100). Preeclampsia with severe features, a secondary outcome, was higher in FA pregnancies (4.4% vs 2.9%, p < 0.001), and FA remained independently associated with preeclampsia with severe features (OR 1.259, 95% CI 1.105–1.435). In this analysis of U.S. delivery hospitalizations, FA was not associated with SMM or overall HDP but was associated with preeclampsia with severe features.