Estratest and Pregnancy
Clinical studies on Estratest and pregnancy show that the testosterone component of the medication could cause serious problems, especially for a female fetus. Even if the testosterone hormone is given for a short time during pregnancy, it can cause virilization of the female fetus, which can result in male-like genitalia. If you are taking Estratest and pregnancy occurs, contact your healthcare provider immediately.
Estratest® (esterified estrogens/methyltestosterone) is a prescription estrogen and testosterone medication. It is not intended for use in pregnant women, as it can cause serious problems for the fetus.
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 X is given to medications that should not be used during pregnancy, usually due to serious problems that could occur, such as birth defects or miscarriages. Technically, the FDA has not given Estratest a pregnancy Category rating because the drug has never been approved by the FDA. However, the manufacturer of Estratest assumes that it is a pregnancy Category X medicine.
The estrogens in Estratest probably will not cause any harm to a developing fetus, but they are of no benefit when used during pregnancy (estrogens do not prevent miscarriages or other problems).
More importantly, the testosterone in Estratest can cause serious problems, especially for a female fetus. Testosterone hormones, even given for a short time during pregnancy, can cause virilization (masculinization) of the female fetus. This can result in ambiguous or male-like genitalia in a female.