infectious diseases
Trimethoprim and Sulfamethoxazole
Use During Pregnancy and Breastfeeding
Animal reproduction studies with TMP/SMX show some risk (eg, birth defects). Data related to pregnancy in humans is inadequate. However, use of TMP/SMX should be avoided during the 1st trimester (because neural tube defects are a risk) and near term. If used during pregnancy or in neonates, TMP/SMX increases blood levels of unconjugated bilirubin and increases risk of Kernicterus in the fetus or neonate. If TMP/SMX cannot be avoided during the 1st trimester, Sulfonamides enter breast milk, and use during breastfeeding is usually discouraged. 