This sheet is about exposure to St. John’s wort in pregnancy and while breastfeeding. This information is based on available published literature. It should not take the place of medical care and advice from your healthcare provider.
What is St. John’s wort?
St. John’s wort (Hypericum perforatum) is a flowering plant that has been used as an herbal supplement. It is available as a tablet or capsule, liquid extract, tea, and as a cream or ointment. It is also sometimes mixed with other herbal ingredients in combination products. St. John’s wort has most commonly been used to help symptoms of mild to moderate depression. MotherToBaby has a fact sheet on depression at: https://mothertobaby.org/fact-sheets/depression-pregnancy/.
There are many compounds in St. John’s wort. The amount and quality of these compounds can vary widely and be affected by the soil the plant was grown in, and how the plant was harvested, dried, and stored. St. John’s wort can interact with many medications (change how well they work in the body or cause side effects), including birth control pills. If you are taking any medication, talk to your healthcare providers to review the chance of interactions between your medication and St. John’s wort.
In the United States, St. John’s wort is a dietary supplement. Unlike prescription medication, dietary supplements are not regulated by the Food and Drug Administration (FDA) in the same way and do not have set standards for preparation, safety, or effectiveness. For information on supplements in general, please see the fact sheet on herbal products at https://mothertobaby.org/fact-sheets/herbal-products-pregnancy/.
Sometimes when people find out they are pregnant, they think about changing how they take supplements or their medication. It is important to talk with your healthcare providers before making changes in how you take your medication or your supplements. Your healthcare providers can talk with you about the benefits of treating your condition and the risks of untreated illness during pregnancy. Your healthcare team might discuss medication options that have been better studied for use in pregnancy.
I take St. John’s wort. Can it make it harder for me to get pregnant?
It is not known if St John’s Wort can make it harder to get pregnant.
Does taking St. John’s wort increase the chance for miscarriage?
Miscarriage is common and can occur in any pregnancy for many different reasons. One study found the chance for a miscarriage in people taking St. John’s wort during pregnancy to be similar to the general population’s chance for miscarriage.
Does taking St. John’s wort 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. Three studies that looked at pregnancies with use of St. John’s wort did not find an increase in birth defects.
Does taking St. John’s wort in pregnancy increase the chance of other pregnancy related problems?
A study that included 39 people who reported using St. John’s wort early in their pregnancies did not find a higher chance for preterm delivery (delivery before 37 weeks of pregnancy) or poor growth in the babies. A second study of 54 infants prenatally exposed to St. John’s wort found a similar rate of live birth and preterm delivery when compared to babies not exposed to St John’s wort. There is 1 case report of a person who started taking St. John’s wort at week 24 of pregnancy and developed thrombocytopenia but had a normal delivery. Thrombocytopenia is a condition where the blood does not have enough platelets (cells that help your blood to clot). Some reports suggest that St. John’s wort can affect how a person’s blood clots. It is not known if the low platelet count in this case report was related to St. John’s wort or another factor.
Does taking St. John’s wort in pregnancy affect future behavior or learning for the child?
Studies have not been done to see if St. John’s wort can cause behavior or learning issues for the child.
Breastfeeding while taking St. John’s wort:
St. John’s wort gets into breastmilk. In 5 people who were breastfeeding full-term older infants (10-22 weeks of age), the amount of St. John’s wort that the infants received through breastmilk was found to be small. The parents reported no negative effects in their infants. Another study that looked at 33 people who took St. John’s wort and breastfed reported an increased amount of crying (colic) and being very sleepy (lethargy) in their infants when compared to infants of people with depression who were not taking St John’s wort. The infants did not need medical treatment. If you suspect the baby has any symptoms from the St. John’s wort such as colic, drowsiness, or poor feeding, contact the child’s healthcare provider. Be sure to talk to your healthcare provider about all of your breastfeeding questions.
If a male takes St. John’s wort, could it affect fertility or increase the chance of birth defects?
St. John’s Wort has not been well studied to see how it might affect male fertility (ability to get a partner pregnant) or increase the chance of birth defects above the background risk. There are case reports of sexual difficulties (reduced desire or ability to perform) in people taking St. John’s Wort; similar things were reported in laboratory animals studies. Experimental laboratory data have suggested that St. John’s Wort might have spermicidal effects (kill sperm or reduce ability to swim towards the egg). In general, exposures that fathers or sperm donors 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/.
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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.
