The use of certain antibiotics early in pregnancy may have detrimental effects on a woman and her unborn baby. A new research has found a link between these medications and an increased likelihood for miscarriage.
Antibiotics That May Increase Risk For Miscarriage
For the new study published in the Canadian Medical Association Journal on May 1, researchers found evidence suggesting that taking certain antibiotics known as quinolones, tetracyclines, sulfonamides, and macrolides may not be good for women in the early stage of their pregnancy.
Study researcher Anick Bérard, from the University of Montreal in Canada, and colleagues found that use of these classes of antibiotics before the 20th week of pregnancy is linked to a small increase in risk for pregnancy loss.
For their study, the researchers looked at the data collected from the Quebec Pregnancy Cohort from the years 1998 to 2008, which contain information on pregnancies covered by Quebec's drug insurance plan.
By comparing the cases of more than 8,700 women who had a miscarriage during the early weeks of pregnancy to about the same number of women who did not, the researchers found an association between use of quinolones, tetracyclines, sulfonamides, and macrolides and miscarriage.
"Although antibiotic use to treat infections has been linked to a decreased risk of prematurity and low birth weight in other studies, our investigation shows that certain types of antibiotics are increasing the risk of spontaneous abortion, with a 60 percent to twofold increased risk," Bérard said.
The researchers said that the severity of infection could contribute to pregnancy loss and may help explain some of the increased risks, albeit this variable was not factored in during the analysis.
"The main reason for confounding by indication in our study may be differences in the severity of infections. However, we adjusted for several documented proxies for infection severity, such as prior exposure to antibiotics, comorbidities, hospital-based diagnosis of maternal infections, and prior hospital admissions," the researchers wrote.
Pregnant Women Need Not Be Fearful Of Taking Antibiotics
Experts also said that the findings of the study should not make pregnant women fearful of taking antibiotics. For one, infection in pregnant women can also increase the risk of babies developing health conditions such as diabetes and other autoimmune diseases.
"My biggest worry would be that women would not take needed therapy for serious infections and therefore put their health and their baby's health at risk," said infectious disease expert Dr. Deborah Money from the University of British Columbia.
Other types of antibiotics such as penicillin, erythromycin, nitrofurantoin, and cephalosporin are fortunately considered safe for pregnant women and have even been shown to reduce the chances for low birth weight and premature delivery. None of these have been associated with birth defects.
The researchers said that the findings show that the most commonly prescribed drugs are also the safest are reassuring since use of antibiotics is common in pregnancy. Pregnant women can be at risk for vaginal yeast infection. Hormonal changes during pregnancy such as increased levels of estrogen disrupt vaginal pH, which can lead to yeast overload.