Children who were exposed to antibiotics during their mother's pregnancy had a higher risk of obesity by the age of seven, according to a study by Columbia University. In addition, children who were delivered by Caesarean section were at increased risk.
Previous studies have linked antibiotics prescribed in early childhood with an increased risk of obesity, but the new study was the first to show that maternal use of antibiotics during the second or third trimester increased the offspring's obesity risk.
Researchers know that antibiotics affect microbes in the mother, and they believe the microbes may enter fetal circulation via the placenta. Recent research shows that the bacteria that normally live in our colon have important roles in maintaining our health, and that imbalances in these bacterial populations can cause a variety of illnesses. Interruptions in the normal transmission of bacteria from the mother to the child are thought to place the child at risk for several health conditions, including obesity.
The new study, which followed 436 mothers and their children for seven years, found that children of moms who took antibiotics during their second or third trimester had an 84 percent higher risk of being obese at age seven than children whose moms didn't take antibiotics.
Children who were delivered by Caesarean section faced a 46 percent increase in obesity.
Caesarean section birth is thought to reduce the normal transmission of bacteria from the mother to the child, and to disturb the balance of bacteria in the child in much the same way as antibiotics.
"Further research is needed on how mode of delivery, antibiotic use during pregnancy and other factors influence the establishment of the ecosystem of bacteria that inhabit each of us," said researcher Andrew Rundle, associate professor of epidemiology at Columbia University Mailman School of Public Health. "This research will help us understand how to create an early platform to support the healthy growth and development of children."
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