Is St. John's Wort Safe During Pregnancy?

St. John's Wort During Pregnancy
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Question:  Is St. John's Wort a safe alternative to prescription medications during pregnancy?

Answer: Right now it's simply not known if the herbal antidepressant St. John's wort, also known as Hypericum perforatum, is safe during pregnancy. The data that are available are from in vitro studies (those performed outside a living animal, for example, in a test tube), animal studies, or isolated case reports of women who took it during pregnancy.

Some in vitro studies have shown genetic damage to mammalian cell lines exposed to high Hypericum extract concentrations. Others have shown impaired sperm motility, decreased sperm penetration of the egg, and denaturation of sperm DNA with exposure to very high concentrations of Hypericum extract.

Two controlled trials in mice demonstrated a significant reduction in birth weight of mice exposed to St. John's wort in the uterus, but no difference in neurobehavioral development or reproductive capacity. Another similar study in rats showed that female rats exposed to Hypericum prenatally required more time to learn a new maze task. The clinical relevance of this, however, is uncertain. One randomized, blinded trial on rats showed reduced size and reduced number of somites in rats exposed to hypericin, a substance found in St. John's wort.  There is also some evidence that St. John's wort can cause birth defects in unborn rats.

The two human case reports of women self-treating with St. John's wort reported no ill effects to either mother or infant.

Given the limited data regarding the safety of St. John's wort during pregnancy and the wide availability of other treatment options, such as psychotherapy and prescription antidepressants, St.

John's wort is not recommended for pregnant women at this time.


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