Some antibiotics may be linked to an increased risk of miscarriage

In reality, viruses and infections can happen when you're pregnant, especially because your immune system is working overtime to keep both you and your baby healthy. Although antibiotics are commonly prescribed during pregnancy, a new study by researchers at the Université de Montréal suggests that if you’re pregnant, you may want to ditch certain drugs.

In the study, which was published Monday in the Canadian Medical Association Journal, researchers looked at the medical records of more than 180,000 pregnancies in the Quebec Pregnancy Cohort for women ages 15 to 45 between 1998 and 2009.

Researchers found a link between pregnancies that ended in miscarriage and women who'd filled at least one prescription starting on their first day of gestation, or had filled one before gestation but were still taking the drugs at the start of their pregnancy.

The study's author, Flory T. Muanda, M.D., wrote that the fetal safety of certain antibiotics are of particular concern. What look out for? Azithromycin (prescribed for things like strep throat), clarithromycin (prescribed for things like pneumonia), tetracyclines (prescribed for acne and syphilis), doxycycline (prescribed for things like urinary tract infections and gum disease), minocycline (prescribed for things urinary tract infections, acne, and chlamydia), quinolones (prescribed for pronchitis, sinusitis, and pneumonia), ciprofloxacin (prescribed for things like infectious diarrhea and urinary tract infections), norfloxacin (prescribed for urinary tract and other gynecological infections), levofloxacin (used to treat kidney and bladder infections or respiratory infections), sulfonamides (used to treat urinary tract infections), and metronidazole (used to treat yeast infections).

So what does this mean if you're pregnant and develop an infection? Should you skip antibiotics completely? Not so fast, says Iffath Hoskins, M.D., clinical associate professor, department of obstetrics and gynecology at NYU Langone Medical Center.

"To me, when I read this paper, it is about being more careful," Hoskins says. "We should remind ourselves that [antibiotics are] not as harmless as we would like to believe. Here is another study showing us there is a burden to be extra careful." If you are pregnant and think you might be developing an infection, don't seek an antibiotic "just in case," Hoskins says.

But if you are pregnant and have an active infection, not treating it can sometimes pose a greater risk than taking an antibiotic, Hoskins notes. "Don't avoid an antibiotic if you truly need it," Hoskins says. "Work it out with your doctor. A lot of the infections that are in this study like urinary tract and respiratory infections are known to cause pregnancy loss if left untreated."

The best thing you can do is treat any infections before your pregnancy, Hoskins says. If you are planning to get pregnant, you should go to your doctor for a "tune-up."

"For a women who is playing to get pregnant, go to your doctor and say 'Hi, Dr. Jones, I am planning to get pregnant' as simple as that," Hoskins says. "The doctor will make sure you don't have any underlying infections, check your body mass, nutrition, exercise. It's like a tune-up of the car. If there's an infection and you are planning to get pregnant, that's the time to treat."

The bottom line, Hoskins says, is to see your doctor immediately if you think you have an infection.

"Don't take this article and scare yourself to death so you don't take an antibiotic," she says. "A doctor will decide if the benefit is worth the risk."