The information provided below is for readers based in the United States of America. Readers outside of the United States of America should seek the information from local sources.


Despite limited evidence in human pregnancy, bortezomib is expected to cause harm to the developing baby. Bortezomib should not be used during pregnancy or while breastfeeding.

What is bortezomib?

Bortezomib is a toxic medication used to treat cancers such as multiple myeloma.

What is bortezomib used to treat?

Bortezomib is a prescription medication used for mantle cell lymphoma and multiple myeloma after a prior therapy has been tried.

How does bortezomib work?

Bortezomib is a type of anticancer medication known as proteasome inhibitor. Bortezomib interferes with cellular enzymes known as proteasomes to cause cancer cell death.

If I am taking bortezomib, can it harm my baby?

Bortezomib is expected to cross the human placenta to reach the developing baby. Animal and human studies have linked bortezomib to death and negative effects on growth in the developing baby.

If I am taking bortezomib and become pregnant, what should I do?

It is recommended to use contraception to avoid pregnancy while on bortezomib therapy and for at least 2 months after stopping therapy. Pregnancy testing is performed in women prior to starting this medication. If the medication is required during pregnancy, the woman must be advised on the safety risks. If the medication is not required, it is best to avoid taking bortezomib during pregnancy to prevent harm to the baby. If a woman becomes pregnant while on bortezomib, the risks of this medication should be discussed.

If I am taking bortezomib, can I safely breastfeed my baby?

Bortezomib is expected to pass into human breast milk, although how much of the medication infants are exposed to is unknown. It is recommended to avoid breastfeeding while taking this medication and for at least 2 months after stopping this medication.

If I am taking bortezomib, will it be more difficult to get pregnant?

Animal studies have found that bortezomib can cause degeneration of the ovaries and testes with exposure to doses lower than human doses.

If I am taking bortezomib, what should I know?

Bortezomib is a toxic medication. It is recommended to avoid this medication during pregnancy unless needed. Women who take bortezomib after delivery should avoid breastfeeding. 

If I am taking any medication, what should I know?

This report provides a summary of available information about the use of proteasome inhibitors during pregnancy and breastfeeding. Content is from the product label unless otherwise indicated.

You may find Pregistry's expert reports about oncology here,  reports about the individual medications used to treat cancer here, and a report about cancer here. Additional information can also be found in the resources below. 

For more information about bortezomib during and after pregnancy, contact (800-994-9662 [TDD: 888-220-5446]) or check the following link:

Velcade: Velcade Prescribing Information

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General information

It is very common for women to worry about having a miscarriage or giving birth to a child with a birth defect while they are pregnant. Many decisions that women make about their health during pregnancy are made with these concerns in mind.

For many women these concerns are very real. As many as 1 in 5 pregnancies end in a miscarriage, and 1 in 33 babies are born with a birth defect. These rates are considered the background population risk, which means they do not take into consideration anything about the health of the mom, the medications she is taking, or the family history of the mom or the baby’s dad. A number of different things can increase these risks, including taking certain medications during pregnancy.

It is known that most medications, including over-the-counter medications, taken during pregnancy do get passed on to the baby. Fortunately, most medicines are not harmful to the baby and can be safely taken during pregnancy. But there are some that are known to be harmful to a baby’s normal development and growth, especially when they are taken during certain times of the pregnancy. Because of this, it is important to talk with your doctor or midwife about any medications you are taking, ideally before you even try to get pregnant.

If a doctor other than the one caring for your pregnancy recommends that you start a new medicine while you are pregnant, it is important that you let them know you are pregnant.

If you do need to take a new medication while pregnant, it is important to discuss the possible risks the medicine may pose on your pregnancy with your doctor or midwife. They can help you understand the benefits and the risks of taking the medicine.

Ultimately, the decision to start, stop, or change medications during pregnancy is up to you to make, along with input from your doctor or midwife. If you do take medications during pregnancy, be sure to keep track of all the medications you are taking.