A new study reports that antibiotic use during pregnancy is associated with an increased risk for obesity in the child.
Researchers studied
436 mothers and their children from birth until age 7, gathering data on
antibiotic use from interviews. After controlling for gestational age,
birth weight, breast-feeding, maternal body mass index and socioeconomic
status, among other variables, they found that antibiotic use during
the second and third trimesters was associated with an 84 percent
increased risk for obesity in the child.
The study, published in the International Journal of Obesity,
also found that cesarean section was associated with a 46 percent
increased risk for obesity in the offspring, confirming previous
studies.
The authors
acknowledge that they had no data on which antibiotics were administered
or for what infections, factors that could have affected their results.
The mechanism is
unclear, and the study shows only an association, but the lead author,
Noel T. Mueller, a postdoctoral research fellow at Columbia, suggested
that the prenatal exchange of antibiotics between mother and child may
affect the colonization of bacteria in the newborn’s gut.
“The current findings
in and of themselves shouldn’t change clinical practice,” he said. “If
they hold up in other prospective studies, then they should be part of
the equation when considering antibiotic usage. There are many
legitimate uses for antibiotics during pregnancy.”