Study Unraveles Impact of Maternal Hypertensive Disorders on Neurodevelopment in Preterm Infants

Recent study aimed to investigate the associations between maternal hypertensive disorders of pregnancy (HDP), particularly preeclampsia, and neurodevelopmental outcomes in preterm infants at 2 years' corrected age. A regional prospective cohort study of 395 preterm infants born at Յ32 weeks' gestation was conducted. The main outcomes measured were structural brain magnetic resonance imaging at term-equivalent age and neurodevelopmental assessment using the Bayley Scales of Infant and Toddler Development (BSID), Third Edition, between 22 and 26 months' corrected age. Preeclampsia affects 2% to 5% of pregnancies and is linked to premature birth and neurodevelopmental deficits due to disruptions in fetal brain development. Hypertensive disorders of pregnancy, including preeclampsia, impact 5% to 15% of pregnancies and share similar mechanisms with preeclampsia that can affect brain development, leading to cognitive, motor, and behavioral issues in children. While HDP exposure has been associated with suboptimal neurodevelopmental outcomes in full-term infants, findings in preterm infants have been inconsistent, with some studies showing worse outcomes, while others suggest a protective role.

Neurodevelopmental Outcomes

In the cohort of preterm infants, HDP-exposed infants had lower cognitive and language scores on the BSID at 2 years' corrected age. Preeclampsia-exposed infants showed greater reductions in scores. Mediation analyses revealed that brain abnormalities partially mediated the effect of HDP on lower cognitive scores. Adjusting for histologic chorioamnionitis, a risk factor for preterm birth and adverse neurodevelopmental outcomes, was crucial in this study.

Study Strengths and Recommendations

The study's strengths included population representation, precise exposure, and outcome assessments, standardized brain MRI scoring, and rigorous confounder control. Notably, the study highlighted the importance of addressing biases from inadequate adjustment of confounders and inappropriate adjustment of intermediate variables in previous research. The findings underscored the need for closer monitoring and early interventions in HDP-exposed preterm infants to improve long-term outcomes. Understanding the mechanisms through which HDP affects neurodevelopment, such as its impact on early brain development, is crucial for refining risk stratification and enhancing early identification of developmental delays for targeted interventions. Enhanced efforts to prevent or treat maternal hypertension may help reduce the risk of abnormal brain development and neurodevelopmental deficits in preterm infants.

Key Points

- The study aimed to investigate the associations between maternal hypertensive disorders of pregnancy (HDP), particularly preeclampsia, and neurodevelopmental outcomes in preterm infants at 2 years' corrected age. Preeclampsia is linked to premature birth and neurodevelopmental deficits due to disruptions in fetal brain development.

- HDP exposure in preterm infants was associated with lower cognitive and language scores on the Bayley Scales of Infant and Toddler Development (BSID) at 2 years' corrected age, with more significant reductions in scores observed in preeclampsia-exposed infants.

- Brain abnormalities partially mediated the effect of HDP on lower cognitive scores in preterm infants. Adjusting for histologic chorioamnionitis, a risk factor for adverse neurodevelopmental outcomes, was crucial in the analysis.

- The study emphasized the importance of population representation, precise exposure and outcome assessments, standardized brain MRI scoring, and rigorous confounder control. It highlighted the need to address biases in previous research related to inadequate adjustment of confounders and inappropriate adjustment of intermediate variables.

- Early monitoring and interventions are recommended for HDP-exposed preterm infants to improve long-term outcomes. Understanding the mechanisms through which HDP affects neurodevelopment, particularly its impact on early brain development, is crucial for risk stratification and early identification of developmental delays.

- Preventing or treating maternal hypertension may help reduce the risk of abnormal brain development and neurodevelopmental deficits in preterm infants. Efforts in this direction could lead to improved outcomes for preterm infants exposed to hypertensive disorders during pregnancy.

Reference –

Shipra Jain et al. (2025). Maternal Hypertension And Adverse Neurodevelopment In A Cohort Of Preterm Infants. *JAMA Network Open*, 8. https://doi.org/10.1001/jamanetworkopen.2025.7788.