Antibiotics during pregnancy may increase child’s ................

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 seven, 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 per cent 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 per cent 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 University, suggested that the prenatal exchange of antibiotics between mother and child may affect the colonisation of bacteria in the newborn’s gut.