Centuries before drugstores popped up on every corner, women relied on herbal remedies to get them through the discomforts of pregnancy. They'd eat ginger to ease morning sickness or drink raspberry leaf tea to shorten labor.
Herbal remedies might seem like a better option than medicines because they come from plants. But just because they're natural doesn't mean these products are safe for you and your baby. A review of 74 studies on herbal supplement use in pregnancy found concerning side effects from some remedies. Ginger was associated with heartburn, belly pain, and nausea. Almond oil, which is used to prevent stretch marks, was linked to preterm birth. And raspberry leaf was associated with an increased likelihood of C-section delivery.
Compared to medications, a lot is unknown about supplements. "In order to get FDA approval, medications need to undergo rigorous studies," says Shivani Patel, MD, an assistant professor of obstetrics and gynecology at UT Southwestern Medical Center in Dallas. "Supplements have not undergone that process, so there's no way to know that they're truly safe."
The most commonly reported side effects in the study were GI complaints like nausea, vomiting, and diarrhea, which could dehydrate a pregnant woman. "She could have contractions, which could potentially put her into preterm labor," Patel says.
It's hard to predict which side effects a supplement might cause, or even to know exactly what's in the bottle. When Canadian researchers analyzed the DNA in 44 herbal products, they found that most contained genetic material from plant species not listed on the labels. Some herbal products are laced with chemicals, pesticides, or other dangerous contaminants.
Science doesn't offer women much guidance, either. As the authors of the review acknowledged, many of the studies they analyzed weren't of high quality. It's hard to prove that herbal remedies -- and not other things -- caused the side effects documented in the studies.
Until we know more about the risks of herbal supplements, don't use them without medical advice. "If you're considering taking a supplement, talk to your doctor about it," Patel says.
Some herbs, such as ginger, may be helpful if you take them in the right dose and form. "Ginger does treat nausea very well, but if you take too much, it can cause heartburn," says Patel. Ginger ale and ginger candies may be easier on your stomach than straight ginger.
One supplement you definitely do want to take is a prenatal vitamin. It contains folic acid, which helps prevent neural tube birth defects such as spina bifida, and iron, which helps your baby grow and develop normally. Ideally, you should start taking a prenatal vitamin before you conceive and continue taking it throughout your pregnancy.
By the Numbers
15%: Percentage of pregnant women who said they used herbs and supplements.
25%: Percentage of pregnant women who don't tell their doctor about their herbal supplement use.
79%: Percentage of herbal supplements tested that didn't contain the plants listed on the product label.
400 micrograms: How much folic acid pregnant women should get each day from foods or supplements.
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