This sheet is about exposure to olanzapine in pregnancy and while breastfeeding. This information should not take the place of medical care and advice from your healthcare provider.
What is olanzapine?
Olanzapine is a medication that has been used to treat schizophrenia, major depressive disorder, and bipolar disorder. It has also been used with other medications to treat anorexia and symptoms of dementia. Olanzapine belongs to a group of medications called atypical or second-generation antipsychotics. A brand name for olanzapine is Zyprexa®.
Sometimes when people find out they are pregnant, they think about changing how they take their medication, or stopping their medication altogether. However, it is important to talk with your healthcare providers before making any changes to how you take this medication. Your healthcare providers can talk with you about the benefits of treating your condition and the risks of untreated illness during pregnancy.
Some people may have a return of their symptoms (relapse) if they stop this medication during pregnancy. If you plan to stop this medication, your healthcare provider may suggest that you slowly lower the dose instead of stopping all at once. Stopping this medication suddenly can cause some people to have withdrawal symptoms. It is not known if or how withdrawal symptoms may affect a pregnancy.
I take olanzapine. Can it make it harder for me to get pregnant?
In some people, olanzapine may raise the levels of a hormone called prolactin. High levels of prolactin can stop ovulation (part of the menstrual cycle when an ovary releases an egg). This would make it harder to get pregnant. Your healthcare provider can test your levels of prolactin if there is concern.
Does taking olanzapine increase the chance for miscarriage?
Miscarriage is common and can occur in any pregnancy for many different reasons. Based on the studies reviewed, it is not known if olanzapine increases the chance for miscarriage. Studies suggest that when depression is untreated or not well-treated, there may be an increased chance for miscarriage. This makes it hard to know if a medication, the medical condition being treated, or other factors are the cause of a miscarriage.
Does taking olanzapine increase the chance of birth defects?
Every pregnancy starts out with a 3-5% chance of having a birth defect. This is called the background risk. Based on the studies reviewed, olanzapine is not expected to increase the chance of birth defects above the background risk. Studies looking at over 2500 babies exposed to olanzapine during early pregnancy or throughout pregnancy suggest that olanzapine use is unlikely to increase the chance of birth defects.
Does taking olanzapine in pregnancy increase the chance of other pregnancy-related problems?
Based on the studies reviewed, it is not known if olanzapine can cause other pregnancy-related problems, such as preterm delivery (birth before week 37) or low birth weight (weighing less than 5 pounds, 8 ounces [2500 grams] at birth).
Some studies suggest that taking olanzapine throughout pregnancy may increase the chance of gestational diabetes. Gestational diabetes can increase the chance for other complications such as preterm delivery or the fetus being larger than expected (called macrosomia). Talk with your healthcare provider about your risk for gestational diabetes. If needed, they can monitor your blood sugar levels before and during pregnancy. More information about gestational diabetes can be found in our fact sheet at https://mothertobaby.org/fact-sheets/diabetes-pregnancy/.
Research has also shown that when depression is left untreated during pregnancy, there could be an increased chance for pregnancy complications. This makes it hard to know if a medication, the medical condition being treated, or other factors are increasing the chance for these problems. For more information on depression, please see our fact sheet at https://mothertobaby.org/fact-sheets/depression-pregnancy/.
I need to take olanzapine throughout my entire pregnancy. Will it cause withdrawal symptoms in my baby after birth?
The use of olanzapine during pregnancy can cause temporary symptoms in newborns soon after birth. These symptoms are sometimes referred to as withdrawal. Babies born to a person taking olanzapine near delivery can be watched for symptoms such as stiff or floppy muscle tone, drowsiness, agitation, trouble with breathing, trouble with feeding, or tremors. Symptoms usually go away in a few days. Not all babies exposed to olanzapine will have these symptoms. It is important that your healthcare providers know you are taking olanzapine so that if symptoms occur your baby can get the care that’s best for them.
Does taking olanzapine in pregnancy affect future behavior or learning for the child?
Studies have not been done to see if olanzapine can cause behavior or learning issues for the child.
Breastfeeding while taking olanzapine:
Olanzapine passes into breastmilk in small amounts. Most reports did not find side effects in infants exposed to olanzapine through breastmilk. In one study, symptoms such as irritability, tremors, being more sleepy than usual, having trouble sleeping or staying asleep were reported in a small number of infants. If you suspect the baby has any symptoms (irritability, tremors, or having any sleep problems), contact the child’s healthcare provider. Be sure to talk to your healthcare provider about all of your breastfeeding questions.
If a male takes olanzapine, could it affect fertility (ability to get partner pregnant) or increase the chance of birth defects?
Using olanzapine may raise a person’s levels of the hormone prolactin, which may affect fertility. Studies have not been done to see if olanzapine could increase the chance of birth defects above the background risk. In general, exposures that fathers or sperm donors have are unlikely to increase the risks to a pregnancy. For more information, please see the MotherToBaby fact sheet Paternal Exposures at https://mothertobaby.org/fact-sheets/paternal-exposures-pregnancy/.
Please click here for references.
National Pregnancy Registry for Psychiatric Medications: There is a pregnancy registry for people who take psychiatric medications, such as olanzapine. For more information you can look at their website: https://womensmentalhealth.org/research/pregnancyregistry/.
OTIS/MotherToBaby encourages inclusive and person-centered language. While our name still contains a reference to mothers, we are updating our resources with more inclusive terms. Use of the term mother or maternal refers to a person who is pregnant. Use of the term father or paternal refers to a person who contributes sperm.
