Does Echinacea Cause Infertility or Birth Defects?
Preliminary animal studies suggest that high doses of echinacea may reduce fertility. This has not, however, been demonstrated in humans.(11)
Is Echinacea Safe to Use During Pregnancy?
Results of one animal study suggest that Echinacea purpurea may cause miscarriages. However, this was a tiny study involving only 3 mice in the echinacea treated group, and human studies have not found the same.(35-37)
Echinacea does block growth factors that promote the development of new blood vessels in tumors. These same growth factors are necessary to healthy placenta formation. This has led some experts to speculate that echinacea may be harmful to a healthy pregnancy.(16)
Case Report of Pregnancy Complications
Indeed, there has been one case report of pregnancy complications possibly linked to echinacea use. The mother took an herbal product containing Echinacea angustifolia daily for almost 2 months to treat a common cold. Before taking echinacea her 27-week clinical exam was uneventful. However, at 35 weeks of pregnancy, her doctors found reduced amniotic fluid and fetal growth.(38)
The baby was delivered by emergency cesarean. Though preterm and only about 3 pounds at birth, the newborn baby was fine. The reporting physicians concluded that even though a link could not be proven, the known effects of echinacea on growth factors suggest pregnant women shouldn't use it for long periods of time.(38)
Possible Positive Impact of Echinacea on Pregnancy
Despite these lab and animal studies, echinacea has not been found to cause adverse side effects in fetal organ development. Echinacea may also counteract the side effects of anticonvulsant drugs that are linked to birth defects (such as cleft palate).(16)
Population Studies in Pregnant Women
Results of 2 population studies suggest echinacea is safe to use during pregnancy:
- A prospective study involving 206 women found no statistical difference in miscarriage or birth defects in those who took echinacea compared to those who didn't use the herb. A total of 112 women used echinacea, in various forms, in the first trimester of pregnancy.(36)
- The Norwegian study involved almost 70,000 women and their children. There was no link found between echinacea use by pregnant women and adverse pregnancy outcomes.(37)
However, experts still caution that these studies are insufficient to conclude echinacea is definitely safe to use during pregnancy. They therefore recommend that pregnant women not use echinacea.(39)