Makena and Pregnancy
Although it is meant to be used during pregnancy, Makena (hydroxyprogesterone caproate) is not intended for use during the first trimester. If you have a history of preterm birth and are pregnant, it's important to make a timely decision about whether you want to use this medication, as it often takes extra time to obtain, due to insurance and financial issues.
Makena™ (hydroxyprogesterone caproate) is an injectable medication given once a week to help prevent preterm birth (giving birth to a baby too soon). It is likely safe for use during pregnancy, which makes sense, since it is designed specifically for pregnant women. However, Makena is not intended for use in the first trimester.
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 B is given to medicines that have not been adequately studied in pregnant humans but did not appear to cause harm to the fetus in animal studies.
Medications that have been shown to be safe for use in pregnancy in humans but have caused problems in laboratory animals are also given a Category B rating.
Makena should be started sometime between weeks 16 and 21 of pregnancy. It is not approved for earlier use. At this time, there is not enough evidence to say that Makena is safe for use during the first trimester. The drug should be stopped by the week 37 of pregnancy or by delivery, whichever comes first.
In studies of Makena use during the second and third trimesters, there were no increases in birth defects.