Children whose mothers had higher levels of one type of PFAS during pregnancy tended to have slightly more sleep problems between ages 1 and 5, according to a recent ECHO Cohort study led by Sarah D. Geiger, PhD, and Cai Zhang, of the University of Illinois Urbana-Champaign. 

Per- and polyfluoroalkyl substances, or PFAS, are long-lasting chemicals found in many consumer and industrial products. They can remain in the environment and in people’s bodies for a long time. During pregnancy, PFAS can cross the placenta, meaning a developing baby may be exposed before birth. 

Researchers studied 2,836 mother-child pairs from 14 ECHO Cohort study sites across the United States and Puerto Rico. They measured levels of four PFAS chemicals in blood samples collected during pregnancy. Caregivers later answered questions about their children’s sleep, including difficulty falling asleep, waking during the night, nightmares, and resistance at bedtime.  

Higher levels of perfluorooctanoic acid, or PFOA, during pregnancy were linked to slightly more sleep problems in young children. The pattern was similar in boys and girls. The other three PFAS chemicals studied were not clearly linked to children’s sleep problems. 

“Sleep is one of the most common concerns parents raise in early childhood, yet it is rarely studied as an outcome of prenatal chemical exposure,” said Zhang, a doctoral student at the University of Illinois Urbana-Champaign. “The difference for any one child was small, but exposure to these chemicals is widespread, so even small differences are worth continued study.” 

Future studies could examine whether prenatal PFAS exposure continues to relate to sleep as children grow older. Researchers could also study combinations of PFAS, newer replacement chemicals, and sleep measurements collected through wearable devices. 

This collaborative research, titled “Prenatal PFAS exposure and early childhood sleep quality in the ECHO Cohort,” is published in Environmental Research.