Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2017 May 1;189(17):E625-E633.
doi: 10.1503/cmaj.161020.

Use of antibiotics during pregnancy and risk of spontaneous abortion

Affiliations

Use of antibiotics during pregnancy and risk of spontaneous abortion

Flory T Muanda et al. CMAJ. .

Abstract

Background: Although antibiotics are widely used during pregnancy, evidence regarding their fetal safety remains limited. Our aim was to quantify the association between antibiotic exposure during pregnancy and risk of spontaneous abortion.

Methods: We conducted a nested case-control study within the Quebec Pregnancy Cohort (1998-2009). We excluded planned abortions and pregnancies exposed to fetotoxic drugs. Spontaneous abortion was defined as having a diagnosis or procedure related to spontaneous abortion before the 20th week of pregnancy. The index date was defined as the calendar date of the spontaneous abortion. Ten controls per case were randomly selected and matched by gestational age and year of pregnancy. Use of antibiotics was defined by filled prescriptions between the first day of gestation and the index date and was compared with (a) non-exposure and (b) exposure to penicillins or cephalosporins. We studied type of antibiotics separately using the same comparator groups.

Results: After adjustment for potential confounders, use of azithromycin (adjusted odds ratio [OR] 1.65, 95% confidence interval [CI] 1.34-2.02; 110 exposed cases), clarithromycin (adjusted OR 2.35, 95% CI 1.90-2.91; 111 exposed cases), metronidazole (adjusted OR 1.70, 95% CI 1.27-2.26; 53 exposed cases), sulfonamides (adjusted OR 2.01, 95% CI 1.36-2.97; 30 exposed cases), tetracyclines (adjusted OR 2.59, 95% CI 1.97-3.41; 67 exposed cases) and quinolones (adjusted OR 2.72, 95% CI 2.27-3.27; 160 exposed cases) was associated with an increased risk of spontaneous abortion. Similar results were found when we used penicillins or cephalosporins as the comparator group.

Interpretation: After adjustment for potential confounders, use of macro-lides (excluding erythromycin), quinolones, tetracyclines, sulfonamides and metronidazole during early pregnancy was associated with an increased risk of spontaneous abortion. Our findings may be of use to policy-makers to update guidelines for the treatment of infections during pregnancy.

PubMed Disclaimer

Conflict of interest statement

Competing interests: Anick Bérard is a consultant for plaintiffs in litigations involving antidepressants and birth defects. No other competing interests were declared.

Figures

Figure 1:
Figure 1:
Selection of pregnancies for analysis.
Figure 2:
Figure 2:
Risk of spontaneous abortion associated with use of antibiotics during pregnancy (3 comparator groups: no antibiotic use, exosure to penicillins and exposure to cephalosporins). Values greater than 1.0 indicate an increased risk of spontaneous abortion. CI = confidence interval, OR = odds ratio. *Odds ratios were adjusted for covariates listed in Methods. Includes cefixime, cefuroxime, cefaclor and cefprozil. Includes pivampicillin, ampicillin and cloxacillin sodium. §Includes spiramycin and telithromycin. Includes moxifloxacin and ofloxacin. **Includes tetracycline and demethylchlortetracycline.

Comment in

References

    1. Bar-Oz B, Diav-Citrin O, Shechtman S, et al. Pregnancy outcome after gestational exposure to the new macrolides: a prospective multi-center observational study. Eur J Obstet Gynecol Reprod Biol 2008;141:31–4. - PubMed
    1. Bar-Oz B, Weber-Schoendorfer C, Berlin M, et al. The outcomes of pregnancy in women exposed to the new macrolides in the first trimester: a prospective, multicentre, observational study. Drug Saf 2012;35:589–98. - PubMed
    1. Sarkar M, Woodland C, Koren G, et al. Pregnancy outcome following gestational exposure to azithromycin. BMC Pregnancy Childbirth 2006;6:18. - PMC - PubMed
    1. Einarson A, Phillips E, Mawji F, et al. A prospective controlled multicentre study of clarithromycin in pregnancy. Am J Perinatol 1998;15:523–5. - PubMed
    1. Andersen JT, Petersen M, Jimenez-Solem E, et al. Clarithromycin in early pregnancy and the risk of miscarriage and malformation: a register based nationwide cohort study. PLoS One 2013;8:e53327. - PMC - PubMed

MeSH terms