Metformin and Pregnancy
Metformin is generally considered safe to take during pregnancy. The FDA has classified the drug as a pregnancy Category B medication, meaning that it does not appear to cause harm to the fetus in animal studies. If you are pregnant or thinking of becoming pregnant, be sure to talk to your healthcare provider about metformin before taking the medication.
For women who are pregnant, metformin (Glucophage®) or metformin ER (Glucophage XR®) are generally considered safe. This is based on animal studies that looked at the effects of metformin during pregnancy.
The U.S. Food and Drug Administration (FDA) uses a pregnancy category system to classify the possible risks to a fetus when a specific medicine is taken during pregnancy. Pregnancy Category B is given to medicines that have not been studied in pregnant humans, but do not appear to cause harm to the fetus in animal studies.
However, it is important to note that animals do not always respond to medicines in the same way that humans do, and so the full risks of using metformin during pregnancy are not known. Therefore, it is always a good idea to talk to your healthcare provider before taking any medication (including metformin) if you are expecting.
Although it is not approved for this use, metformin is commonly used for treating infertility related to polycystic ovarian syndrome (PCOS). In this case, sometimes the medicine is continued during pregnancy. Be sure to follow your healthcare provider's instructions for using this product during pregnancy.
(Click PCOS and Metformin for more information, including why metformin is sometimes used throughout pregnancy.)