On January 12, 2018, the CDC published a report about health care providers dispensing to pregnant women antibiotics that have a risk of birth defects. Use of sulfonamides and nitrofurantoin during early pregnancy carries a risk of birth defects, including anencephaly (a serious birth defect in which a baby is born without parts of the brain and skull), heart defects, and orofacial clefts (cleft lip and cleft palate; birth defects that occur when a baby’s lip or mouth do not form properly during pregnancy). Given the risks and the potential for unrecognized pregnancy, women’s health care providers should be familiar with the recommendation that sulfonamides and nitrofurantoin only be prescribed in the first trimester when other antimicrobial therapies are deemed clinically inappropriate and consider the possibility of early pregnancy when treating women of reproductive age.
Urinary tract infections (UTIs) occur in approximately eight percent of pregnant women, and untreated UTIs can have serious consequences, including pyelonephritis (a potentially organ- and/or life-threatening infection that often leads to renal scarring), preterm labor, low birth weight, and sepsis. Pregnant women are typically screened for UTIs during early pregnancy, and those with bacteria in their urine are treated with antibiotics.
Because of the potential risk for birth defects, including anencephaly, heart defects, and orofacial clefts, associated with use of sulfonamides and nitrofurantoin during pregnancy, a 2011 committee opinion from the American College of Obstetricians and Gynecologists (ACOG) recommended that sulfonamides and nitrofurantoin may be prescribed in the first trimester of pregnancy only when other antimicrobial therapies are deemed clinically inappropriate. To assess the effects of these recommendations, the CDC analyzed a database of employed persons with private employer-sponsored insurance and their dependents to examine antibiotic prescriptions filled by pregnant women with UTIs. Among 482,917 pregnancies in 2014, 7.2 percent of women had an outpatient UTI diagnosis during the 90 days before the date of last menstrual period (LMP) or during pregnancy. Among pregnant women with UTIs, the most frequently prescribed antibiotics during the first trimester included nitrofurantoin, one of the antibiotics ACOG warned should be avoided, and trimethoprim-sulfamethoxazole, which consists of one part trimethoprim to five parts sulfamethoxazole, a sulfonamide from the family of antibiotics ACOG warned should be avoided.
UTI diagnoses were most frequent during the first trimester of pregnancy (41.0% of UTIs) and least frequent in the third (11.8%). Type of antibiotic dispensed differed for UTIs treated before and during pregnancy. Fluoroquinolones (e.g., ciprofloxacin) and sulfonamides (e.g., trimethoprim-sulfamethoxazole) were more commonly dispensed to women within 90 days before their LMP than to pregnant women during any trimester of pregnancy. In contrast, nitrofurantoin, cephalosporins (e.g., cephalexin), and penicillins (e.g., amoxicillin) were more commonly dispensed during pregnancy than during the 90 days before LMP. The most frequently dispensed antibiotics during the first trimester of pregnancy were nitrofurantoin (34.7%), ciprofloxacin (10.5%), cephalexin (10.3%), and trimethoprim-sulfamethoxazole (7.6%).
According to 2011 guidelines from the Infectious Diseases Society of America, nonpregnant women with uncomplicated UTIs should be treated with nitrofurantoin or trimethoprim-sulfamethoxazole. For pregnant women in their first trimester, a 2011 Committee Opinion from the American College of Obstetricians and Gynecologists recommended that sulfonamides and nitrofurantoin may be prescribed only if other antimicrobial therapies are deemed clinically inappropriate. In this analysis, 34.7 percent of pregnant women with UTIs in 2014 filled a prescription for nitrofurantoin and 7.6 percent filled a prescription for trimethoprim-sulfamethoxazole during their first trimester of pregnancy.
The CDC’s analysis of a large insurance claims database demonstrated that, in 2014, nitrofurantoin and trimethoprim-sulfamethoxazole were common treatments for women with UTIs during their first trimester of pregnancy. Improving antibiotic selection is an important aspect of antibiotic stewardship and these antibiotics have potential risks associated with early pregnancy use, particularly during organogenesis. Given the recommendations to avoid these medications in early pregnancy if possible and the fact that nearly 50 percent of pregnancies in the United States are unintended, it is important that health care providers of various specialties be aware of these recommendations and that they might be treating a woman with an unrecognized pregnancy when prescribing antibiotic treatments for UTIs.
See the CDC Report
See also Medical Law Perspectives Report: Drugs, Dosage, and Damage: Physician Liability for Prescribing or Administering Medication
See the Medical Law Perspectives Blog: Is Stillbirth Medical Malpractice Success Directly Proportional to Weeks of Pregnancy?
See the Medical Law Perspectives Blog: Florida’s No-Fault Compensation System for Severe Birth Injury Claims Fails Again