Infectious injury to a fetus’ lungs can be detected by monitoring for an increase in specific inflammatory proteins in the amniotic fluid, a study finds.

“This gives us a tool to track, and detect this infection prior to delivery,” said Stephen McCartney, MD, lead author of the study, which was published in the American Journal of Obstetrics and Gynecology. Kristina Adams Waldorf, MD, was senior author. Both are physician-researchers in obstetrics and gynecology at the University of Washington School of Medicine.

Infection within the uterus can lead to preterm birth and also injure a fetus’ lungs, McCartney said. Until now, there has not been a good way to determine whether an infection has injured the fetal lungs before birth. Currently, preterm infants are evaluated only after birth to determine how well their lungs function.

This study tracked the progression of a common pregnancy infection, Group B Streptococcus, and the associated inflammatory response in fetal lungs of nonhuman primates. The investigators compared the ability of either placental inflammation or inflammatory proteins in the amniotic fluid, mother’s blood, and fetal blood to correlate with fetal lung injury. The best predictor of fetal lung injury were the inflammatory proteins interleukin-6 and interleukin-8 in amniotic fluid. 

These findings support an expanded role for amniocentesis to evaluate the inflammatory response in amniotic fluid as a clinical predictor of fetuses at risk for poor pulmonary outcomes, he said.