TUESDAY, Oct. 6, 2026 (HealthDay News) — A child’s risk of ADHD might start in the womb, a new study says.
The health of an expecting mother’s placenta during late pregnancy appears to be linked to increased risk of ADHD, researchers reported recently in JAMA Psychiatry.
Specifically, lower levels of a protein called placental growth factor (PlGF) during pregnancy were linked to higher odds of a child’s later diagnosis of ADHD, researchers found.
“This study adds to the evidence that neurodevelopmental risk begins in utero and suggests that the placenta may play a major role in shaping neurodevelopmental outcomes,” said lead researcher Serena Gumusoglu, an assistant professor of psychiatry, obstetrics and gynecology at the University of Iowa.
“It raises the exciting possibility that factors known to be related to pregnancy and maternal health, like PlGF, may also tell us something about how the baby's brain is developing,” Gumusoglu said in a news release.
As many as 10% of American kids ages 3 to 17 have ADHD, which interferes with their ability to focus, pay attention and be thoughtful in their actions, researchers said in background notes.
For this study, researchers used blood samples banked from 176 pregnancies to look for levels of PlGF, a protein made by the placenta. Low levels of PlGF are a known warning sign for pregnancy complications like preeclampsia.
The team then compared PlGF levels to later ADHD diagnoses among the children from these pregnancies.
The placenta is a temporary organ that forms in a woman’s womb during pregnancy. It is responsible for providing oxygen and nutrients to a developing fetus through the umbilical cord.
PlGF levels in the first and second trimesters did not appear linked to ADHD risk, but that changed with the third trimester.
“In pregnancies that resulted in a child later diagnosed with ADHD, we saw that PlGF levels did not have the typical increase in the third trimester,” Gumusoglu said. “Each standard-deviation drop in PlGF was associated with 2.6 times higher odds of a later ADHD diagnosis in the child.”
This link held even after researchers accounted for preeclampsia, early preterm birth and restricted fetal growth, conditions that have already been linked to both lower PlGF levels and higher odds of ADHD, researchers said.
Results also showed no link between ADHD risk and levels of endothelin-1, another protein that contributes to blood vessel health and function during pregnancy.
“This is important because it indicates that we aren't just flagging 'sick' pregnancies,” Gumusoglu said. “Our results point to subtle placental changes in pregnancies that did not have a clinical diagnosis yet still resulted in neurodevelopmental differences in children.”
However, Gumusoglu cautioned that these results are from a relatively small group of pregnancies at one medical center. More research will be needed to confirm and better understand this potential association.
"This work links what is classically considered an obstetric concern — abnormal PlGF — to neurodevelopmental outcomes years later in children,” Gumusoglu said. “If our result is replicated in a larger sample and if a causal relationship is supported by studies in mice, it would suggest that measuring pregnancy levels of PlGF might help identify children who would benefit from earlier developmental monitoring.”
More information
The Mayo Clinic has more about the placenta.
SOURCE: University of Iowa, news release, Sept. 30, 2026
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