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.


Use of olanzapine during the third trimester is linked to possible withdrawal symptoms the newborn baby such as agitation, respiratory distress, and feeding issues – it may also increase the risk of gestational diabetes and glucose intolerance in the mother.

What is olanzapine?

Olanzapine is a newer generation antipsychotic medication known as an atypical antipsychotic.

What is olanzapine used to treat?

Olanzapine is prescription medication used to treat bipolar disorder and schizophrenia.

How does olanzapine work?

Olanzapine blocks the effects of dopamine and serotonin in the brain.

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

Olanzapine does cross the human placenta to reach the baby. Studies have reported no serious birth defects associated with olanzapine use during pregnancy; however, prematurity and changes in birth weight (either low or high) have been reported. First trimester exposure to olanzapine is not associated with an increased risk of birth defects. Use of olanzapine during the third trimester is linked to possible withdrawal symptoms in infants such as agitation, respiratory distress, and feeding issues. Olanzapine may also increase the risk of gestational diabetes and glucose intolerance in the mother.

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

It is important that bipolar disorder and schizophrenia therapy be individualized for each patient. The risks should be weighed against the benefits of continuing antipsychotic therapy during pregnancy. Women who are attempting to conceive or become pregnant while on olanzapine should speak with their doctor. Women with chronic or severe disorders may need to continue on olanzapine therapy during pregnancy. Olanzapine is a commonly used antipsychotic in pregnancy.

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

Olanzapine is passed to the baby through breast milk. It is estimated that breastfeeding infants receive about 1.8% to 2% of the mother’s dose. Sedation (sleepiness) has been reported in infants exposed to olanzapine though their mother’s breast milk. The dose of olanzapine can be lowered to reduce the risk of side effects in the breastfeeding infant if the mother can tolerate the lower medication dose. Olanzapine is also associated with increased prolactin production which increases breast milk production. It is important to speak with your doctor to determine if continuing on olanzapine is safe during breastfeeding. The American Academy of Pediatrics has stated that antipsychotics have an unknown effect on breastfeeding infants and may be a concern. The manufacturer of olanzapine recommends not breastfeeding while on this medication.

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

Olanzapine may be associated with sexual side effects. Animal studies report impaired sperm production in males. Females may experience decreased fertility or an increase in body fat.

If I am taking olanzapine, what should I know?

Treatment for bipolar disorder or schizophrenia should be individualized during pregnancy. Studies have not shown an increase in birth defects with olanzapine exposure in utero, but further studies need to be conducted. Olanzapine can affect birth weight and can cause withdrawal effects such as respiratory distress in infants. The risk versus benefits of taking or not taking olanzapine should be weighed carefully.

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

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

You may find Pregistry’s expert report about bipolar disorder here, reports about other mental health disorders here, and reports about the individual medications used to treat mental health disorders here.   Additional information can also be found in the resources below. 

For more information about olanzapine during and after pregnancy, contact http://www.womenshealth.gov/ (800-994-9662 [TDD: 888-220-5446]) or check the following link:

Lilly.com:  Zyprexa Prescribing Information

Read the whole report
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.