Pegasys and Pregnancy
Animal studies indicate that Pegasys (peginterferon alfa-2a) may not be safe for use in women who are expecting. In these studies, a similar drug appeared to increase the risk for miscarriages. Also, Pegasys is sometimes used in combination with ribavirin, a medicine that should never be used during pregnancy. You may be advised to use birth control to avoid getting pregnant during treatment.
Can Pregnant Women Use Pegasys?Pegasys® (peginterferon alfa-2a) is a prescription injection used to treat hepatitis B and C. This drug may not be safe for use during pregnancy. Animal studies suggest that Pegasys may increase the risk for miscarriages.
What Is Pregnancy Category C?
Pegasys is classified as a pregnancy Category C drug. 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 adequately studied in pregnant humans but have caused fetal harm in animal studies. In addition, medicines that have not been studied in any pregnant women or animals are automatically given a pregnancy Category C rating.
When given to pregnant monkeys, a drug similar to Pegasys called interferon alfa-2a caused miscarriages. However, the medication did not appear to increase the risk for birth defects, probably because interferons are not expected to cross the placenta.
Pegasys has not been studied in pregnant humans. There are reports of similar interferon medications being used during pregnancy without any problems. However, such reports cannot rule out the possibility of rare complications.
Of utmost importance, Pegasys is sometimes used in combination with ribavirin (Rebetol®), a medication that must never be used during pregnancy. Ribavirin can cause birth defects and fetal death. Women who will be taking it must have a negative pregnancy test before starting treatment and must use two forms of birth control during treatment. The potential effects of the drug on a fetus are so severe that a man should not even take ribavirin if his female partner is pregnant.