When you go to the doctor feeling under the weather, you hope that any medication you're prescribed will heal you without unintended consequences. However, a study published yesterday in the Canadian Medical Association Journal suggests pregnant women seeking treatment for UTIs may be at higher risk for spontaneous abortion if prescribed certain antibiotics, even ones commonly prescribed during pregnancy.
The study was conducted by researchers from the Université de Montréal in Canada using data from the Quebec Pregnancy Cohort about 95,000 pregnancies. Researchers at the Université de Montréal in Canada found that of these pregnancies, 8,502 ended in miscarriage before the 20th week, and in 1,428 of these cases (16 percent), the women were exposed to antibiotics during the early stages of their pregnancy. Antibiotic exposure, for the purposes of this study, was considered as at least one prescription during the early gestation period. Of the women who experienced miscarriage, 560 of them had been prescribed penicillin and cephalosporins; both of these are antibiotics that have been tested at length and proven safe.
Doctors have already been discouraged from prescribing tetracyclines and quinolones, two types of antibiotics, to pregnant women, as both can affect fetal development. However, the other classes of antibiotics prescribed to the rest of the cases came into question during this study. Other antibiotics the researchers found to increase the risk of miscarriage were sulfonamides, macrolides (excluding erythromycin), and metronidazole. Use of azithromycin and clarithromycin, two types of macrolides, were found to be associated with 65 percent and 200 percent greater risk of spontaneous abortion, respectively. This is especially unsettling given that both of these are used to bacterial infections, including bronchitis and ear, throat, and sinus infections.
The study did find that nitrofurantoin, penicillin, and cephalosporins weren't associated with higher likelihood of spontaneous abortion, making them safe options for pregnant women with infections. Anick Bérard, the lead author on the study and professor at the Faculty of Pharmacy at the Université de Montréal, told Broadly that while the findings of this study are important, the risk of miscarriage due to antibiotics is still fairly minimal. Given that the incidence of miscarriage is, on average, around 6 to 7 percent without antibiotic exposure, and the findings in the study show a risk of nine to ten percent with exposure, it's a relatively small increase — though the link is still an important one for pregnant patients and care providers to be aware of.
More on pregnancy:
- 6 Common Pregnancy Skin Issues and Their Solutions
- Are Prenatal Multivitamins Worth the Investment?
- The Surprising Way Chrissy Teigen Is Preventing Pregnancy Stretch Marks
What Happens to Your Body After You Have a Baby: