Mom’s hypertension can affect preterm infant brain and neurodevelopment, experts report

Many women already know that preeclampsia—a dangerous form of high blood pressure during pregnancy—can lead to serious complications including kidney failure, stroke, and even death. Preeclampsia is also a well-known cause of preterm birth, which can pose a number of health risks for the baby.

Now, a new study led by experts at Cincinnati Children’s reports that preterm infants born to women who battled preeclampsia also show signs of brain injury soon after birth and worse neurodevelopment two years later. And to a lesser extent, so do the preterm-born toddlers of women who had gestational hypertension and chronic hypertension (a growing global health concern).

Specifically, a group of more than 340 preterm infants cared for at five Ohio neonatal intensive care units showed decreased cognitive and language scores at age 2 if they were born to mothers affected by high blood pressure.

These findings were published in JAMA Network Open by investigators with the Cincinnati Infant Neurodevelopment Early Prediction Study (CINEPS). Shipra Jain, MD, Division of Neonatology and Pulmonary Biology, was lead author and Nehal Parikh, DO, MS, a neonatologist with Cincinnati Children’s Perinatal Institute, was the senior author.

“These reduced scores can be clinically meaningful because even slight differences can signal increased risk for later cognitive, language, or motor impairments,” Parikh says. “Since development is dynamic, even a small early disadvantage can compound over time, especially if the child lacks supportive interventions, potentially affecting school readiness and/or later academic achievement.”

The risks of hypertension

Preeclampsia affects 2% to 5% of all pregnancies, while a broader category that also includes gestational hypertension and chronic hypertension impacts up to 15% of all pregnancies. The brain development deficits among infants are believed to be caused by reduced blood flow to the placenta, reduced oxygen levels in the blood, tissue inflammation, and tissue damage caused by oxidative stress.

While some of these problems have been previously documented in full-term infants born to mothers with high blood pressure, previous studies focused on preterm infants had shown mixed results. Some studies have reported worse cognitive and motor outcomes, others have found no association, while a few even suggested a protective role.

This study accounted for several confounding variables that impacted other studies, and by doing so, the research team confirmed adverse brain impacts among preterm infants born at 32 weeks or less.

Maternal high blood pressure was significantly associated with adverse cognitive and language outcomes, with the greatest effects among preeclampsia-exposed infants, independent of other risk factors. Additionally, the study found these adverse effects may be partially caused by early abnormalities in brain development.

What do these children need?

The study co-authors say these findings suggest that even mild effects occurring at birth—if left undetected or unaddressed—can magnify into larger deficits as children approach school age.

“Our findings thus support an association between maternal high blood pressure and early brain abnormalities and potentially harmful direct effects on cognitive and language development,” Jain says.

“We believe early identification of brain abnormalities can allow for targeted interventions, such as early speech therapy, occupational therapy, or enriched learning environments, which can improve long-term educational, behavioral, and health outcomes, especially when preeclampsia occurs.”

One way to detect the risk may be to conduct MRI brain scans to detect brain abnormalities, especially in the white matter, for all preterm infants affected by preeclampsia. The researchers recommend incorporating such brain scans into future clinical trials evaluating therapies to manage or prevent maternal hypertension or preeclampsia.

About the study

The Cincinnati Infant Neurodevelopment Early Prediction Study (CINEPS) was launched in 2016. The study uses advanced neuroimaging techniques to more accurately predict motor, cognitive, and behavioral deficits in very preterm infants (less than 32 weeks gestational age).

Enrollment in the study closed in November 2019, but long-term follow-up to age 7 and analysis of the data collected continues. This is the 40th study to be published based on the CINEPS cohort.