New study links antibiotics to increased risk of miscarriage

A new study published in the Canadian Medical Association Journal links the use of certain antibiotics during pregnancy to the increased risk of a miscarriage.

The study, led by Dr. Anick Bérard, a member of the Faculty of Pharmacy at the Université de Montréal, found that five antibiotics -- macrolides, quinolones, tetracyclines, sulfonamides and metronidazole -- were all related to higher rates of pregnancy loss.

To reach this conclusion, Bérard and her team looked at the data of pregnant women in the Quebec between 1998 and 2009 in order to compare the patients' prescription histories to their rate of miscarriages.

The team found that 16.4% of the women who miscarried had taken antibiotics early in their pregnancies, compared to only 12.6% of the women who had not taken them.

Thankfully, CNN reports that doctors do not prescribe tetracyclines during pregnancy due to the risk of birth defect, and quinolones tend to be avoided as well.

However, three of the drugs the team found to be dangerous may still present a risk to pregnant woman.

According to CNN, Macrolides may sometimes be prescribed when penicillin cannot be used to fight streptococcal and pneumococcal infections, while suflonamides can be used to treat urinary tract infections, ear or eye infections and bronchitis.

Metronidazole may also be used to treat infections of the vagina, stomach, skin, joints and respiratory tract.

Luckily, this heightened chance of pregnancy loss did not seem to be correlated with the most frequently used antibiotics, including penicillin.