Infectious diseases that occur during pregnancy and the puerperium pose special risks to the mother, fetus, and infant. Any intervention must be weighed against possible side effects.

Urinary tract infections

For pregnant women it is recommended to culture urine at the first prenatal visit. Treatment should be provided if the urine culture is positive.

Short courses (3 days) of antimicrobial therapy are usually effective in eradicating asymptomatic bacteriuria. Penicillins, cephalosporins, aztreonam, ertapenem, imipenem, and meropenem are considered safe. Sulfonamides, including TMP–SMX, are avoided in the first trimester and near term (because of kernicterus).

Recommended regimens include amoxicillin, 500 mg orally three times a day; amoxicillin–clavulanate, 875mg twice a day; nitrofurantoin, 100mg every 12 hours; sulfisoxazole, 500 mg three times a day; cephalosporins, such as cefuroximeaxetil, 250 to 500mg every 12 hours, or cefpodoxime, 100mg every 12 hours, can also be used. Fosfomycin, 3 g PO as a single dose, was shown to be effective when compared with other drugs administered for a longer time.

Urine culture should be performed 1 week after therapy and monthly until the end of pregnancy. Suppressive therapy until delivery is recommended for women who have persistent bacteriuria after two or more courses of therapy.

In acute cystitis, pyuria is found in most patients, and urine culture should be performed. Patients should be treated for 3 to 7 days if symptoms suggesting pyelonephritis are absent. The same antibiotic regimens suggested for asymptomatic bacteriuria can be utilized. Quinolones are contraindicated in pregnancy. Follow-up urine culture should be obtained 1 week after therapy. For recurrent infections, antimicrobial prophylaxis should be considered for the duration of pregnancy.