This sheet talks about exposure to miglustat during pregnancy and breastfeeding. This information should not take the place of medical care and advice from your healthcare provider.

What is miglustat?

Miglustat is a medication that has been used for treatment of mild to moderate Type I Gaucher disease and Niemann-Pick disease, type C. It is used in individuals with Gaucher disease when enzyme replacement therapy is not recommended. It is sold under the brand name Zavesca®.

People with Gaucher disease have a deficiency of the enzyme called glucocerebrosidase (gloo-co-se-ruh-BRO-si-dace). This enzyme helps break down fatty substances in the body. When this enzyme is missing or not working, fatty substances build up and can cause organ damage. Miglustat works in the body to limit the amount of the fatty substance being made. For more information, see the MotherToBaby fact sheet Gaucher Disease at https://mothertobaby.org/fact-sheets/gaucher-disease-pregnancy/pdf/

I take miglustat. Can it make it harder for me to get pregnant?

Studies have not been done to see if miglustat could make it harder for a woman to get pregnant.

I just found out I am pregnant. Should I stop taking miglustat?

Talk with your healthcare providers before making any changes to this medication. It is important to talk about the risks and benefits of treatment options for your pregnancy.

Does taking miglustat increase the chance of miscarriage?

Miscarriage can occur in any pregnancy. Studies in animals found a greater chance of pregnancy loss. Studies have not been done to see if miglustat could increase the chance for miscarriage in humans.

Does taking miglustat in the first trimester increase the chance of birth defects?

In every pregnancy, a woman starts out with a 3-5% chance of having a baby with a birth defect. This is called her background risk. Studies have not been done to see if miglustat increases the chance for birth defects in humans.

Could taking miglustat in the second or third trimester cause other pregnancy complications?

Studies have not been done to see if miglustat increases the chance for birth defects or other pregnancy complications in humans. Studies in animals found a greater chance of low birth weight.

Does taking miglustat in pregnancy cause long-term problems in behavior or learning for the baby?

Studies have not been done to see if miglustat causes cause long-term problems in behavior or learning.

Can I breastfeed while taking miglustat?

There are no studies looking at miglustat use while breastfeeding. It is possible that miglustat could enter breastmilk, but studies are needed to confirm this. The effects on a nursing infant are unknown. Be sure to talk to your healthcare provider about all of your breastfeeding questions.

If a man takes miglustat, could it affect his fertility (ability to get partner pregnant) or increase the chance of birth defects? 

There are no studies looking at possible risks to a pregnancy when the father takes miglustat. Animal studies in rats found that miglustat exposure decreased sperm production, which lowered fertility. However, this was not found in all animal studies. In humans, one report did not find miglustat use in men affected the production of sperm or their fertility. In general, exposures that fathers have are unlikely to increase risks to a pregnancy. For more information, please see the MotherToBaby fact sheet Paternal Exposures at  https://mothertobaby.org/fact-sheets/paternal-exposures-pregnancy/pdf/.

Selected References:

    • Granovsky-Grisaru, S et al. The management of pregnancy in Gaucher disease. 2011. Thromb Haemost, 156:3-8.
    • Hollak, C et al. Miglustat (Zavesca®) in type I Gaucher disease: 5-year results of a post-authorisation safety surveillance programme. 2009. Pharmacoepidemiol Drug Saf 18:770-777.
    • Miglustat (Zavesca®) Product Label. [Accessed 8/2017] https://www.accessdata.fda.gov/drugsatfda_docs/label/2014/021348s010lbl.pdf