Is green tea safe during pregnancy?

The verdict

Green tea is safe in pregnancy in moderation. No health authority in the UK, US, Canada, Australia or New Zealand lists it as a food or drink to avoid.

The only limit that applies is your total daily caffeine, and green tea counts towards it like any other caffeinated drink. On the NHS's own numbers, that works out at roughly two to three cups a day if you drink nothing else caffeinated - and fewer if you also have coffee.

Why there is a limit at all

Caffeine, not the tea. Green tea is made from the same plant as black tea, Camellia sinensis, processed without oxidation. The NHS treats them identically for caffeine purposes: 75mg in a cup of tea - for example, black or green tea.

Caffeine crosses the placenta, and the pregnant body clears it progressively more slowly as pregnancy advances, so the same cup produces a longer exposure than it would have before. The NHS links too much caffeine to a higher chance of miscarriage and stillbirth; NICE cites low birth weight. ACOG's Committee Opinion 462, reaffirmed in 2026, concludes that intake below 200mg a day does not appear to be a major contributing factor in miscarriage or preterm birth.

A second mechanism is sometimes raised: the catechins in green tea, particularly EGCG, can inhibit dihydrofolate reductase, the enzyme involved in folate metabolism, which in theory could reduce folate availability at a time when folate matters most. No health authority in any of the five countries has translated this into consumer guidance, set a limit on that basis, or advised against green tea for that reason. It is a laboratory observation, and it is presented here as one - it does not currently change what anyone is told to do. If you are drinking green tea, keep taking folic acid as advised and the question is moot.

How much is too much - and the numbers disagree

This is where green tea gets genuinely awkward, because the two most detailed national estimates of its caffeine content differ by more than twofold.

The NHS puts a cup of tea, black or green, at 75mg. Against a 200mg daily ceiling, that is 2.6 cups a day and nothing else.

Health Canada puts brewed black or green tea at 30 to 50mg per 8oz (237ml) cup. Against its own 300mg ceiling, that is six to ten cups.

US Department of Agriculture data for brewed green tea gives about 12mg per 100g, which works out at roughly 28mg for an 8oz cup - close to the bottom of Health Canada's range and well under half the NHS figure.

The gap is partly real and partly definitional. Actual caffeine in a cup of green tea depends heavily on leaf quantity, water temperature and steeping time - a two-minute brew and a five-minute brew are not the same drink. Matcha is different again, because you consume the whole leaf rather than an infusion, and is meaningfully stronger than steeped green tea. The NHS is also giving a single figure for all tea, which is conservative for green tea specifically.

The safe way to use these numbers: assume the NHS figure. If you plan on 75mg a cup, you will not accidentally exceed anyone's limit.

Herbal teas are a separate question

Green tea is real tea and contains caffeine. Herbal infusions - peppermint, chamomile, rooibos, fruit teas - are not tea and generally contain none, but the NHS applies a different limit to them: avoid drinking more than 4 cups of herbal tea a day, on the basis that there is not much research on their effects in pregnancy. The NHS also says to avoid herbal teas containing liquorice root entirely, as it may be harmful to your baby's development. Green tea is not covered by either of those rules.

If you have already been drinking a lot

Nothing follows from a period of higher intake. The 200mg figure is a daily average meant to shape a habit, not a threshold that causes harm the moment it is crossed, and no authority recommends testing or intervention on the basis of past caffeine consumption.

If you want to cut down, taper rather than stop abruptly - caffeine withdrawal headaches are unpleasant and entirely avoidable over a week. Decaffeinated green tea exists and is not counted against any limit.

One thing genuinely worth knowing: concentrated green tea extract in capsule or tablet form is a different product from the drink, and NIH's National Center for Complementary and Integrative Health notes that liver injury has been reported in some people who used green tea products, primarily extracts in tablet or capsule form. That is a supplement question rather than a food one and outside what this page covers - but the beverage and the extract are not interchangeable. NCCIH's position on the drink is that no safety concerns have been reported for green tea consumed as a beverage by adults.

Where guidance differs

Nobody bans it. On the central question, every jurisdiction agrees by omission - green tea appears on no avoid list anywhere.

The daily caffeine ceiling differs. The NHS and ACOG both use 200mg. Health Canada uses 300mg for people who are pregnant, planning a pregnancy or breastfeeding. FSANZ publishes no pregnancy caffeine figure at all, stating that there is no recognised health-based guidance value such as an Acceptable Daily Intake. So the number of cups you are permitted depends on which regulator you follow, before you even get to how strong the tea is.

The caffeine content per cup differs by more than the ceiling does. Combining the two divergences produces a striking result: under NHS assumptions, green tea allows about 2.6 cups a day. Under Health Canada's assumptions and ceiling, it allows six to ten. That is a fourfold difference in practical advice between two national regulators about the same drink, and neither is obviously wrong - it is a difference in how conservatively each estimates a brew.

Only the NHS caps herbal tea. The 4-cup-a-day herbal tea limit and the liquorice root warning are UK-specific. No US, Canadian or Australian authority publishes an equivalent, though this does not apply to green tea in any case.