This sheet talks about using mirtazapine in a pregnancy or while breastfeeding. This information should not take the place of medical care and advice from your healthcare provider.

What is mirtazapine?                                    

Mirtazapine is a medication used in the treatment of major depressive disorders. It comes in the form of oral tablets. The brand name for mirtazapine is Remeron®.

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

Mirtazapine can cause an increase in the hormone prolactin. High levels of prolactin in women might make it harder to get pregnant. If you are having trouble getting pregnant while using this medication, talk with your healthcare provider.

I just found out that I am pregnant, should I stop taking mirtazapine?

You should not stop or make changes to your medication without first talking with your healthcare provider. Studies have shown that untreated depression during pregnancy can increase the chance for miscarriage, preeclampsia (dangerously high blood pressure), preterm delivery (delivery before 37 weeks of pregnancy), low birth weight and a number of other harmful effects on the mother and the baby. For more information on depression, please see our fact sheet at https://mothertobaby.org/fact-sheets/depression-pregnancy/pdf/.

The benefits of taking mirtazapine and any possible risks to the baby should be considered before a decision is made to stop taking this medication. If you and your healthcare provider decide together that stopping mirtazapine is right for you, your provider can help you slowly lower the dose over time to avoid withdrawal symptoms.

Does taking mirtazapine increase the chance of miscarriage?

Miscarriages can occur in any pregnancy. A possible association with mirtazapine use in pregnancy and a small increased chance for miscarriage has been suggested. However, at this time it is not confirmed that the use of mirtazapine increases the chance for miscarriage. Some studies suggest that the depression itself rather than the mirtazapine may be increasing the chance of miscarriage.

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

In every pregnancy, a woman starts with a 3-5% chance of having a baby with a birth defect. This is called her background risk. Studies and case reports have looked at nearly 1000 pregnancies where the women were taking mirtazapine and have not found an increased chance for birth defects.

Does taking mirtazapine in the second or third trimester cause other pregnancy complications?

Some studies show an increased chance of preterm delivery. There have been a few reports withdrawal symptoms in babies if their mother used mirtazapine during pregnancy. Not all babies will have withdrawal symptoms. Symptoms reported have been being sensitive to stimulation such as light and sound (called excitability), rapid heart rate, tremors, and problems regulating temperature shortly after birth. These complications are similar to what have been seen with other types of antidepressants. In most cases, these symptoms are mild and go away on their own. Some babies may need to stay in a special care nursery until the symptoms go away.

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

There are no studies looking at whether taking mirtazapine during pregnancy causes changes in the baby’s behavior or learning. Studies on other antidepressants have not found large changes in behavior and development in children exposed to these medications during pregnancy.

Can I take mirtazapine while breastfeeding?

Most case reports have found that mirtazapine will get into breast milk in low amounts, and most nursing babies have not had any reported side effects from the medication. There is no information about on long term effects from exposure through breastfeeding.  Watch your baby to make sure they are not overly sleepy from this medication. Talk to your healthcare provider about your concerns as well as all your breastfeeding questions.

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

There are no studies looking at the fertility of men who take mirtazapine. 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/.

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