Is Tea Safe During Pregnancy?

Black, green, white, matcha, chai, and oolong teas are all sourced from the leaves of the Camellia sinensis plant. They contain caffeine — a natural stimulant that should be limited during pregnancy.

They each provide approximately the following amount of caffeine per cup (240 mL) (2, 3, 4, 5, 6):

• matcha: 60–80 mg
• oolong tea: 38–58 mg
• black tea: 47–53 mg
• chai: 47–53 mg
• white tea: 25–50 mg
• green tea: 29–49 mg

Caffeine can easily cross the placenta, and your baby’s immature liver has difficulty breaking it down. As such, infants are more likely to experience side effects from amounts of caffeine that would otherwise be considered safe for adults.

Research suggests that infants exposed to too much caffeine during pregnancy may have a higher risk of being born preterm or with a low birth weight or birth defects. High caffeine intake during pregnancy may also increase the risk of miscarriage or stillbirth (7, 8, 9).

These risks appear minimal when pregnant women limit their caffeine intake to a maximum of 300 mg per day (8).

However, some women’s genetics may make them more sensitive to the ill effects of caffeine. For instance, research suggests that this small proportion of women may have a 2.4 times higher risk of miscarriage when consuming 100–300 mg of caffeine per day (8).

Caffeinated teas contain less caffeine than coffee and are generally considered safe to drink during pregnancy. However, their intake may need to be limited to avoid consuming too much caffeine per day (10, 11).

summary

Black, green, matcha, oolong, white, and chai teas contain caffeine, a stimulant that should be limited during pregnancy. Although they’re generally safe, women may benefit from limiting their daily intake of these caffeinated teas during pregnancy.

Herbal teas are made from dried fruits, flowers, spices, or herbs and therefore contain no caffeine. However, they may contain other compounds considered unsafe during pregnancy, which may result in risky side effects.

Miscarriage or preterm labor

Teas that may increase your risk of miscarriage or preterm labor include (11, 12, 13, 14, 15):

• fennel
• fenugreek
• sage
• vervain
• borage
• pennyroyal
• licorice
• thyme
• motherwort
• lovage
• blue cohosh
• black cohosh
• frankincense (in large amounts)
• chamomile (in large amounts)

Menstrual bleeding

Teas that may stimulate or increase menstrual bleeding include (12, 16, 17):

• motherwort
• lovage
• frankincense

Birth defects

Teas that may increase the risk of birth defects include (12):

• motherwort
• borage

Other side effects

Moreover, in rare cases, eucalyptus tea may cause nausea, vomiting, or diarrhea. What’s more, a case report suggests that regularly drinking chamomile tea during pregnancy may result in poor blood flow through a baby’s heart (1, 12).

Certain herbal teas may also contain compounds that interact with medications. Therefore, pregnant women should inform their healthcare providers of any herbal teas they are currently consuming or planning on consuming at any time during pregnancy (1).

Keep in mind that, due to the limited amount of research on the safety of herbal teas, a lack of evidence of negative side effects shouldn’t be seen as proof that the tea is safe to drink during pregnancy.

Until more is known, it may be best for pregnant women to remain cautious and avoid drinking any teas that have not yet been shown to be likely safe during pregnancy (18).

summary

Certain herbal teas may be linked to a higher risk of upset stomach, menstrual bleeding, miscarriage, birth defects, or preterm birth. Pregnant women may benefit from avoiding all teas not yet deemed as likely safe for pregnancy.

Teas are not strictly tested or regulated. This means that women may be inadvertently drinking teas contaminated with unwanted compounds, such as heavy metals (19, 20).

For instance, one study tested common off-the-shelf black, green, white, and oolong teas. It found that 20% of all samples were contaminated with aluminum. Moreover, 73% of all samples contained lead levels considered unsafe during pregnancy (21).

In another study, women with the highest intake of green and herbal teas during the first trimester of pregnancy had 6–14% higher blood lead levels than those who drank the least. That said, all blood lead levels remained within the normal range (20).

Due to the lack of regulation, there’s also a risk of herbal teas containing ingredients not listed on the label. This increases the risk that pregnant women end up inadvertently consuming a tea tainted with an undesirable herb, such as the ones listed above.

It’s currently impossible to eliminate this risk. However, you may somewhat minimize it by only purchasing teas from reputable brands.

What’s more, it’s likely best to avoid purchasing teas in bulk, as they have a higher risk of becoming mixed with tea leaves that may be contraindicated during pregnancy from adjacent bulk bins.

summary

The manufacturing of teas is not regulated. As a result, teas may become tainted with unwanted compounds, such as heavy metals or herbs that have been linked to poor pregnancy outcomes.

Most caffeinated teas are considered safe to drink during pregnancy, as long as they do not cause a woman’s total daily caffeine intake to exceed 300 mg (8, 11).

Women who are particularly sensitive to caffeine may benefit from aiming for a maximum of 100 mg of caffeine per day (8).

When it comes to herbal teas, there’s not a lot of research regarding their effects during pregnancy. As such, most health professionals advise pregnant women to avoid consuming any herb in amounts greater than you would find in foods (1, 12, 18).

That said, according to a few studies, herbal teas containing the following ingredients may be safe to consume during pregnancy:

• Raspberry leaf. This tea is considered likely safe and believed to shorten labor and help prepare the uterus for birth. Research shows that it may shorten the length of the second stage of labor, but only by about 10 minutes (11, 22).
• Peppermint. This tea is considered likely safe and commonly used to help relieve gas, nausea, stomach pain, or heartburn. However, no studies could be found to support these benefits (12).
• Ginger. Ginger is one of the most studied herb remedies during pregnancy and considered possibly safe. Research suggests it reduces nausea and vomiting but, when consumed dried, should not exceed 1 gram per day (1, 12).
• Lemon balm. This tea is considered possibly safe and commonly used to relieve anxiety, irritability, and insomnia. However, no study could be found to support these uses, and its safety hasn’t been studied in pregnancy (11).

Although generally considered safe, raspberry leaf may promote uterine contractions while peppermint may stimulate menstrual flow. Therefore, there’s some controversy regarding whether these teas are safe during the first trimester of pregnancy (12, 23).

Therefore, it may be best to avoid drinking these two teas in the first 12 weeks of pregnancy.

summary

Herbal teas considered to be possibly safe or likely safe during pregnancy include raspberry leaf, peppermint, ginger, and lemon balm teas. However, it may be best to avoid raspberry leaf and peppermint teas in the first trimester of pregnancy.

Despite their widespread popularity, not all teas are deemed safe for pregnancy.

Caffeinated teas like black, green, white, matcha, and chai teas are generally considered safe. However, their intake may need to be limited to avoid ingesting excessive amounts of caffeine.

Most herbal teas should be avoided. Raspberry leaf, peppermint, ginger, and lemon balm tea are the only ones currently deemed as potentially safe. However, women may benefit from avoiding the first two during their first trimester of pregnancy.