One of the most serious side effects of letrozole is that if used and a woman becomes pregnant, there is a risk of birth defects. Because the drug is not marketed as a fertility drug and the Food and Drug Administration has never approved the use of the medication in this manner, there is a liability if prescribed to a pregnant woman. Therefore, if woman feels any of these pregnancy signs or symptoms , she should immediately contact her health provider. However, there are no research reports that indicate the drug is dangerous if given to a female prior to pregnancy. Letrozole's mechanism of action is based upon the drugs ability to reduce estrogen levels in females.
Low estrogen in the body can cause a female to have side effects from the medication, which can be treated. The statistical information available on letrozole side effects are based upon the drug being used to treat cancer, not when used for fertility treatment. Some of the side effects witnessed can include; hot flashes, headaches and breast tenderness. Statistical information has not shown that letrozole puts a woman at an increased or decreased risk of miscarriage. Letrozole should never be prescribed to a woman that is already pregnant, when studies were conducted using rats and mice being administered the drug, there was an increased risk of fetal death and malformations. To date there have been no studies performed in human beings, but it is believed that the risks would be the same. Letrozole is not a medication that should be taken without a prescription and strict medical supervision. With all the information available, it is up to a woman to become educated and aware of the side effects of the drug and make the best decision for her unique situation. With the advice of a medical professional, letrozole side effects can be managed and even avoided and a woman can conceive the child she has always longed for.