Retrovir and Pregnancy: An Overview
Retrovir® (
zidovudine) is a prescription
HIV medication that is commonly used in pregnant women. While the full risks of using Retrovir during pregnancy are not currently known, the benefits (for both the mother and the baby) usually outweigh the risks.
Retrovir and Pregnancy Category C
The U.S. Food and Drug Administration (FDA) uses a category system to classify the possible risks to a fetus when a specific medicine is taken during pregnancy. Pregnancy Category C is given to medicines that have not been studied in pregnant humans but that do appear to cause harm to the fetus in animal studies. Also, medicines that have not been studied in any pregnant women or animals are automatically given a pregnancy Category C rating.
In one study, when Retrovir was given to pregnant rats, it increased the risk of miscarriages but did not seem to increase the risk of birth defects. However, another study suggested that very high doses may cause birth defects in rats. In general, animal studies show that Retrovir is probably safe for use during pregnancy, although there is some evidence that it may affect fertility and very early fetal development.
Retrovir has also been studied in pregnant women. In fact, it is approved for use during pregnancy to help prevent the transmission of the HIV virus to the baby. In one study, Retrovir reduced the risk of HIV infection in the newborns by up to 86.7 percent. Overall, these studies showed that the drug did not increase the risk of birth defects or other problems.
Starting Retrovir early in pregnancy may decrease the risk of HIV transmission to the baby. However, current guidelines recommend that it is okay for a woman to wait to start Retrovir until she is 10 to
12 weeks pregnant to limit exposure of the fetus to the medicine during early pregnancy (a critical period for organ development).
