The Associated Press is running a super-scary headline today. “Study ties common antibiotics to birth defects.”
The truth is quite different. We are not talking about first-line antibiotics. Penicillins, erythromycins and cephalosporins have no impact on birth defects. We are not talking here of “common antibiotics.”
We’re talking about two specific antibiotics, sulfonamides (sometimes called sulfa drugs), and nitrofurantoins, used by only 1 in 100 pregnant women.
These did seem to result in a higher rate of birth defects and scientists want to know why.
Among the better known sulfanomides, to which many people are already alerted by allergies, are Bactrim and Sulfatrim. They are most commonly prescribed for staph infections and in some cases of pneumonia.
Nitrofurantoins are usually used against urinary tract infections, and go by brand names like Macrobid and Macrodantin.
Here is how the study worked.
CDC researchers analyzed 13,155 cases of 30 different birth defects, drawn from the National Birth Defects Prevention Study. These were compared to 4,941 controls, women located in the same geographical areas whose babies had no birth defects.
What the authors want is more study on why these results occurred. There is really no need to panic, unless you get your news from AP.
Here is their conclusion in full:
“Determining the causes of birth defects is problematic. A single defect can have multiple causes, or multiple seemingly unrelated defects may have a common cause. This study could not determine the safety of drugs during pregnancy, but the lack of widespread increased risk associated with many classes of antibacterials used during pregnancy should be reassuring.”
Not all medical scares are caused by conflicting scientific studies or new insights. Some are caused by sloppy headlines.
