What risk is associated with Trimethoprim/Sulfamethoxazole in the last month of pregnancy?

Trimethoprim/Sulfamethoxazole, a combination antibiotic commonly used to treat infections, carries a specific risk particularly in the last month of pregnancy. The correct answer highlights the concern regarding the displacement of bilirubin from albumin.

During the late stages of pregnancy, especially in the third trimester, the fetus's bilirubin levels can rise as the liver matures and the ability to process bilirubin becomes established. When sulfamethoxazole is administered, it can displace bilirubin from its binding sites on albumin in the maternal and fetal circulation. This displacement can lead to an increase in free bilirubin levels, which poses a risk for conditions such as kernicterus, a type of brain damage that can occur when high levels of bilirubin accumulate in an infant's blood.

Awareness of this risk is crucial for healthcare providers to ensure appropriate management and monitoring of maternal and fetal health during this critical time. The adverse effects of increased free bilirubin emphasize the importance of cautious prescribing practices for medications that can interfere with bilirubin metabolism in late pregnancy.