Antibiotics in Pregnancy and Lactation

Antimicrobials are among the most commonly used drugs in pregnancy and lactation. They are prescribed for a variety of infections during or following pregnancy, including urinary tract infections, Group B streptococcal colonization, and mastitis. In a recent Centers for Disease Control survey, 30% of women reported taking antibiotics during pregnancy. Antimicrobials can present risks to the pregnant woman (some of which are unique to pregnancy), as well as risks to the unborn fetus or breastfed infant.

In December 2014, the FDA approved new medication labeling requirements for pregnancy and lactation that began to take effect in June 2015. This issue discusses the new labeling, and updates the previous (October 2012) Rx Consultant issue on antimicrobial use in pregnancy and lactation. The principles of adverse drug effects in pregnancy and lactation will be also discussed. Tables 1 and 2 group selected oral antimicrobials into categories based on perceived risks in pregnancy and lactation, with their "retired" FDA pregnancy categories and lactation risk ratings (based on the Hale lactation rating scale), along with commentary. Definitions of the risk categories for both pregnancy and lactation are provided in the appendix of the online version of this issue. Antiretroviral agents for the treatment of HIV infection and hepatitis are not reviewed here because they present a unique set of risk-benefit considerations.

A summary of potential antimicrobial/hormonal contraceptive interactions and counseling advice for patients is provided in the Patient Connection interpretation and prescribing practices. While more detailed information will be available to help guide providers who care for pregnant and breastfeeding patients, the new system also imparts greater responsibility to healthcare providers to protect the mother, unborn fetus, or breastfed baby.