Is ertapenem safe to use during pregnancy?

Safety of Ertapenem During Pregnancy

Ertapenem can be considered for use in pregnancy in select recalcitrant cases, as animal studies showed no teratogenic evidence, though human data are extremely limited. 1

Evidence on Ertapenem Safety in Pregnancy

• According to the FDA drug label, available data from a small number of post-marketing cases with ertapenem use in pregnancy are insufficient to inform any drug-associated risks for major birth defects, miscarriage, or adverse maternal or fetal outcomes 2

• Animal reproduction studies after intravenous administration of ertapenem during organogenesis showed no evidence of developmental malformations in rats at systemic exposures up to approximately 1.2 times the human exposure at the maximum recommended human dose 2

• In pregnant mice, ertapenem administration showed only slight decreases in average fetal weight and an associated decrease in the average number of ossified sacrocaudal vertebrae at doses approximately 3 times the maximum recommended human dose 2

• The North American Clinical Practice Guidelines note that data on ertapenem in pregnancy are extremely limited, but animal studies showed no teratogenic evidence, allowing consideration in select recalcitrant cases 1

Risk Assessment and Clinical Decision Making

• The estimated background risk of major birth defects and miscarriage in the general U.S. population is 2-4% and 15-20% respectively in clinically recognized pregnancies 2

• When considering antibiotics in pregnancy, the maternal benefit of treating serious infections must be weighed against potential fetal risks 1

• For hidradenitis suppurativa specifically, guidelines suggest that ertapenem may be considered in select recalcitrant cases when other safer alternatives are not appropriate 1

• Ertapenem is present in human milk, though at low concentrations. In a study of 5 lactating women, breast milk concentrations ranged from <0.13 to 0.38 mcg/mL within 24 hours of the last dose, becoming undetectable or below quantitation limits by day 5 after discontinuation 2

Alternative Antibiotics with Better Safety Profiles in Pregnancy

• For many infections, other antibiotics with more established safety profiles in pregnancy should be considered first-line options 1

• Cephalexin, azithromycin, and clindamycin are considered safe in pregnancy with no adverse effects reported 1

• Amoxicillin/clavulanic acid is also considered safe and can be administered during pregnancy 1

• Metronidazole can be given in cases of specific infections such as pouchitis, perianal Crohn's disease, or intra-abdominal abscesses 1

Clinical Recommendation

When treating serious infections during pregnancy that require carbapenem therapy:

1. Consider safer, well-studied antibiotics first when appropriate for the infection being treated
2. Use ertapenem only when the potential benefit to the mother outweighs the unknown risk to the fetus
3. If ertapenem is required, use the standard dosing regimen as there are no specific dose adjustments recommended for pregnancy
4. Monitor both maternal and fetal well-being during treatment
5. Consider consulting with maternal-fetal medicine specialists when using ertapenem during pregnancy

While ertapenem offers the convenience of once-daily dosing 3, 4, this benefit should not outweigh safety considerations when selecting antimicrobial therapy during pregnancy.