CDC Links Two Antibiotics Taken During Pregnancy to Subsequent Birth Defects

Researchers at the Centers for Disease Control who studied the effect of antibiotics during pregnancy have discovered a link between birth defects and several types of antibiotics, specifically those to treat urinary tract infections, which are referred to as sulfa drugs and nitrofurantoins. However, the most common antibiotic given during pregnancy, penicillin, appears to be the safest.

The new study is the first large-scale research effort to study the effects of antibiotics on pregnancy. Furthermore, it was the first time that researchers were able to find an association between urinary tract treatments and birth defects. The study, which will be published in the November Archive of Pediatrics and Adolescent Medicine, looked at 13,000 mothers whose infants had birth defects as well as 5,000 women with healthy babies who lived in the same regions. The women were interviewed by phone for six weeks to two years after their pregnancies and any that reported having taken antibiotics during the month before conception through the first three months of pregnancy, were identified as exposed to antibiotics.

While the study is revealing and could help doctors decide which antibiotics to avoid giving to pregnant women, the researchers cited a weakness in the study: the women’s memories of which antibiotics they took could be faulty. Furthermore, the underlying condition, rather than the antibiotics, could have also contributed to birth defects. Nevertheless, the researchers concluded that sulfa drugs caused birth defects such as rare brain and heart problems and shortened limbs. Similarly, nitrofurantoins contributed to heart problems and cleft palate. Overall, the drugs seemed to double or triple the risk of these specific types of birth defects.

For further information and links, please visit Jane Akre’s blog on antibiotics and pregnancy at the National Injury Board News Desk.