Another strike against antibiotics

By now, you know how I feel about antibiotics—or at least the overuse and misuse of them. And now there’s yet another strike against them.

A new study, conducted at Columbia University’s Mailman School of Public Health (from which I have an Master of Public Health degree), showed that children who were exposed to antibiotics in the second or third trimester of pregnancy had a higher risk of obesity at age 7.

Previous studies have shown that antibiotics very early in life can increase obesity risk, but this is the first to make the gestational connection. The study examined healthy, non-smoking, pregnant women who were recruited between 1998 and 2006. Of 727 mothers enrolled in the study, 436 mothers and their children were followed until 7 years of age.

Children whose mothers  used antibiotics in the second or third trimester had 84 percent higher risk of obesity than children who hadn’t been exposed during pregnancy.

What’s the connection here? Antibiotics affect microbes in the mother and may enter fetal circulation via the placenta. The bacteria in our colon have critical roles in maintaining our health, and imbalances in these bacterial populations can cause a variety of illnesses. When a pregnant woman takes antibiotics, it interrupts the normal transmission of bacteria from the mother to the child. Which places the child at risk for several health conditions, including obesity.

This is just one more reason why it’s so critically important not to take antibiotics unless they’re absolutely necessary.


“Prenatal exposure to antibiotics, cesarean section and risk of childhood obesity,” International Journal of Obesity, epub ahead of print, 11/11/14