Metformin during Pregnancy & Breastfeeding

by on May 15, 2012

Metformin has been listed by the FDA as being a category B medication. This means it is considered safe to be administered during pregnancy, though a category B rating indicates studies on human populations, instead of test animal populations, are limited. As it stands, metformin use shows no ill effects to either mother or child.

There is currently no warning with metformin and pregnancy and is it is considered to be safe for use. Studies involving metformin and animals have shown no ill effects to the mother during pregnancy, or the offspring upon birth. Though there are few studies done on a human population, the FDA notes studies involving animals use doses that exceed the recommended dosage by at least two and a half times, and still no adverse effects have been documented. As the studies on animals have been extensive, the FDA is confident in allowing the use of metformin for pregnant women.

As Metformin is used to treat those with type 2 diabetes, it should be noted that pregnant mothers who suffer from uncontrolled severe blood sugar swings might inadvertently increase the risk of certain illnesses to the fetus, such as congenital abnormalities; continuing the use of metformin during pregnancy may, in fact, decrease such risks. As is always the case, however, no drugs should be used by pregnant women unless they are required to treat a pre-existing condition or one that develops during pregnancy.

Metformin Use While Breastfeeding

Studies of animals have shown that Metformin is excreted in a nursing mother’s milk, reaching levels near what may be in the woman’s blood stream.

Hypoglycemia is when the blood sugar is too low, either naturally or because of medicinal intervention. There is a risk for a nursing infant to develop hypoglycemia from a nursing mother who is taking metformin, and it is therefore recommended to consider alternatives. One option is for the mother to discontinue use of the drug and discuss alternative therapies with her doctor. The second option is for the mother to consider discontinuing breastfeeding and turn to bottle feeding.

Should there be any concerns with taking this medication during pregnancy, discuss them with your doctor. When it comes time to consider breastfeeding options, be sure to weight all outcomes, considering the health of both the mother and child, before terminating use of metformin.