Pregnancy Hypertension Linked to Lower Childhood IQ, Large Meta-Analysis Finds
Australia: Children born to mothers with hypertensive disorders of pregnancy face a heightened risk of cognitive and developmental challenges, according to a large systematic review and meta-analysis published in PLOS Medicine. The research shows that while links to autism and global developmental delay diminish when factors such as birthweight and gestational age are considered, a measurable reduction in average IQ persists, underscoring the importance of early monitoring and support for these children.
The study, led by Roxanne M. Hastie from the University of Melbourne’s Perinatal Epidemiology Group and Mercy Perinatal at Mercy Hospital for Women in Victoria, Australia, brings together data from 121 studies encompassing nearly 30 million children worldwide. Investigators pooled evidence from cohort, case–control, and cross-sectional studies to explore how maternal hypertensive disorders—including preeclampsia and gestational hypertension—might influence offspring neurodevelopment, intelligence, and educational outcomes.
The following were the key findings:
- Children exposed in utero to hypertensive pregnancy disorders had a 65% higher odds of developing autism spectrum disorder.
- The odds of attention-deficit/hyperactivity disorder (ADHD) increased by 27% in these children.
- The likelihood of intellectual disability and global developmental delay each rose by 77%.
- Mean intelligence scores were lower by an average of 2.2 points compared with children from unaffected pregnancies.
- After adjusting for gestational age and birthweight, the elevated risks for autism and global developmental delay were no longer statistically significant.
- The reduction in IQ remained evident after adjusting for birthweight but weakened when gestational age was considered, indicating overlapping and complex pathways.
The review team emphasized that despite these nuances, the findings point to a vulnerable population of children who could benefit from proactive developmental assessments and early interventions. Early identification of cognitive or behavioral difficulties can enable timely educational and therapeutic support, potentially improving long-term outcomes.
Researchers also noted limitations within the available evidence. Many of the included studies lacked comprehensive adjustment for confounding factors, and there was considerable variation in study design and quality. Nonetheless, sensitivity analyses excluding high-risk studies did not change the overall conclusions.
While the exact biological mechanisms remain unclear, hypertensive disorders of pregnancy are known to affect placental function and fetal growth, which may influence brain development. Dr. Hastie and colleagues call for further research to disentangle the roles of gestational age, birthweight, and other mediating factors.
The large-scale analysis highlights that children born following hypertensive pregnancies, even those without obvious complications at birth, may carry a subtle but significant risk of lower cognitive performance. The authors advocate early developmental surveillance and targeted support as a prudent strategy to help these children achieve their full potential.
Reference:
Atkinson JA, Gordon HG, Tong S, Walker SP, Mehdipour P, Lindquist AC, et al. (2025) Hypertensive disorders of pregnancy and childhood neurodevelopment: A systematic review and meta-analysis. PLoS Med 22(9): e1004558. https://doi.org/10.1371/journal.pmed.1004558
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