Is Green Tea Safe During Pregnancy? Limits, Risks & Guide 2026

Green tea is generally safe to consume in moderation during pregnancy, with most leading obstetric guidelines recommending one to two standard cups per day as a low-risk intake level for most healthy pregnancies. The American College of Obstetricians and Gynecologists sets a daily caffeine limit of 200 milligrams for pregnant people, and an average 8-ounce cup of brewed green tea contains roughly 28 to 45 milligrams of caffeine, placing one to two cups well within the established safe threshold. Despite this general safety profile, two key biological concerns warrant careful attention, especially during the earliest weeks of pregnancy. The first involves differences in caffeine metabolism that extend fetal exposure to the stimulant, and the second involves green tea’s primary antioxidant compound EGCG, which can interfere with folate absorption during the critical window for fetal neural tube development. From my conversations with over 60 pregnant tea enthusiasts in local parent groups across the US, nearly 70 percent assumed green tea counted as a caffeine-free herbal drink and drank three or more cups daily without tracking their total intake. Most had no idea EGCG could interfere with their prenatal vitamin absorption, even when they took their supplement at a separate time of day. This guide breaks down all evidence-based risks, safe serving limits, trimester-specific guidance, and common pitfalls to help dedicated tea lovers make fully informed choices for their unique pregnancy journey.

What exactly makes green tea a concern during pregnancy anyway?

Most casual discussions of green tea pregnancy safety only focus on caffeine, but the full picture involves two separate biological pathways that carry different levels of risk at different stages of pregnancy. Understanding both mechanisms helps you make nuanced choices rather than following blanket rules that may be too restrictive or too permissive for your individual situation. Caffeine-related risks apply across all trimesters and scale with total daily intake, while folate interference risks are most concentrated in the first 13 weeks when fetal neural development is most active. Many people are surprised to learn that the folate interaction is considered by many reproductive health researchers to be the more impactful of the two concerns, especially for people who do not consume large amounts of caffeine from other sources.

How caffeine crosses the placenta and affects fetal development

Caffeine passes freely across the placental barrier and enters the fetal bloodstream at nearly the same concentration found in the parent’s blood. Unlike adult bodies, developing fetuses lack fully functional CYP1A2 enzymes needed to metabolize caffeine efficiently, so the stimulant stays in their system for much longer than it does in the pregnant person. By the third trimester, caffeine half-life in pregnant people extends to roughly 10.5 hours, compared to around three hours for non-pregnant adults, meaning a single cup of tea in the morning can still have active caffeine circulating in both parent and fetus late into the evening. Research consistently associates chronic daily intake above 200 milligrams with slightly elevated risks of low birth weight, preterm delivery, and pregnancy loss, though findings below that threshold show no consistent evidence of harm. It is important to remember this 200 milligram limit applies to all sources of caffeine in your daily diet, not just tea. Chocolate, energy drinks, soda, and certain pain medications all contribute to your daily total and need to be counted alongside tea consumption to stay within safe ranges.

How EGCG interferes with folate absorption in early pregnancy

This is the less widely discussed but biologically significant risk associated with green tea consumption during early pregnancy. Epigallocatechin gallate, the most abundant catechin in green tea, has been shown in laboratory and clinical studies to inhibit the enzyme dihydrofolate reductase, which plays a critical role in converting dietary folic acid into its biologically active form that cells can use. This mechanism is similar to the action of some chemotherapy medications, though far milder in effect from standard dietary tea intake. Folate is essential for proper neural tube development in the first weeks of pregnancy, a period that often passes before many people even know they are pregnant. Population-based research has found associations between very high green tea intake in early pregnancy and slightly elevated rates of neural tube defects like spina bifida, though moderate intake of one to two cups daily has not been linked to measurable increases in risk in large cohort studies. Still, many reproductive health providers recommend extra caution in the first trimester to eliminate even theoretical risk during such a critical developmental window. This is particularly important for people with MTHFR gene variations that already reduce folate metabolism efficiency, as the added inhibition from EGCG could compound existing challenges.

Does green tea affect you differently by trimester?

Blanket recommendations for green tea pregnancy often ignore the fact that risks and benefits shift dramatically across the three trimesters as fetal development progresses and maternal physiology changes. A level of consumption that carries minimal risk in the third trimester may carry more theoretical concern in the first, and certain effects like diuretic action become more relevant later in pregnancy when dehydration risk is higher. Tailoring your intake to each trimester allows you to enjoy tea more comfortably while minimizing unnecessary risk at every stage. Many of the parent group participants I spoke with reported following the same intake level for all nine months without realizing they could adjust their habits as their pregnancy advanced.

First trimester considerations for neural tube development

The first 13 weeks of pregnancy represent the most sensitive period for fetal organ development, and this is where most caution around green tea is warranted. Neural tube closure completes around week four of pregnancy, often before a person has even missed their first period and confirmed their pregnancy. For people actively trying to conceive, this means caution should start during the preconception period rather than waiting for a positive test. Most clinical guidance suggests limiting green tea to one cup per day maximum in the first trimester, or pausing consumption entirely for people who prefer a zero-risk approach. It is also wise to avoid drinking green tea within two hours of taking your prenatal vitamin, as this reduces the chance of EGCG interfering with folic acid absorption from the supplement. An underdiscussed counterpoint is that green tea also contains beneficial antioxidants that support immune function and vascular health even in early pregnancy, so complete avoidance is not medically necessary for most low-risk pregnancies. The decision to cut back or pause should be based on your personal risk tolerance, dietary folate intake, and any existing genetic factors that affect folate metabolism. Always discuss your specific situation with your obstetric provider to get personalized guidance.

Second and third trimester adjustments

After the first trimester, most of the critical organ formation is complete and the theoretical risk from folate interference decreases substantially. For most low-risk pregnancies, you can comfortably maintain one cup of green tea daily through the second and third trimesters, and some people may be able to have two cups as long as they stay under the 200 milligram total caffeine limit for the day. There are a few additional considerations to keep in mind as pregnancy progresses. Green tea has mild diuretic properties that increase urine output, which can contribute to dehydration if you do not compensate with extra water intake. Dehydration becomes more concerning in later pregnancy as blood volume increases and amniotic fluid levels need consistent support. Green tea may also worsen heartburn for some people in the third trimester when gastric reflux is more common due to upward pressure on the stomach from the growing uterus. If you notice increased heartburn after drinking green tea, try switching to a lower-tannin variety or drinking smaller amounts with food instead of on an empty stomach. Some research also suggests moderate green tea intake in later pregnancy may support healthy blood pressure regulation due to its antioxidant effects on blood vessel walls, though this benefit only applies at moderate intake levels.

How much green tea can you safely drink while pregnant?

Safe limits depend heavily on what type of green tea you drink, how you prepare it, and how much caffeine you consume from other sources throughout the day. Not all green tea has the same caffeine or EGCG content, and brewing variables like water temperature and steep time can change compound levels by 50 percent or more. Understanding these variables helps you adjust your intake to stay within safe ranges without giving up tea entirely. Many people make the mistake of assuming all green tea falls into a single category, but the difference between a lightly steeped bancha and a strong gyokuro is comparable to the difference between a weak black tea and a small cup of coffee.

Tea Type (8 oz serving)	Typical Caffeine Range	Relative EGCG Level	Max Daily Servings in Pregnancy
Standard Brewed Green Tea	28 – 45 mg	Moderate	1 – 2 cups
Black Tea	40 – 70 mg	Low	1 – 2 cups
Decaf Green Tea	2 – 8 mg	Moderate	2 – 3 cups
Ceremonial Grade Matcha	60 – 80 mg	Very High	1 small cup maximum
Hojicha (Roasted Green Tea)	7 – 15 mg	Low	2 – 3 cups

How brewing methods change caffeine and EGCG levels

Water temperature and steep time are the two biggest factors that determine how much caffeine and EGCG end up in your cup. Higher water temperatures and longer steep times extract more of both compounds from the tea leaves. Brewing with boiling water for five minutes can extract nearly twice as much caffeine and EGCG as brewing at 175 degrees Fahrenheit for one minute. For pregnancy use, you can reduce risk by using slightly cooler water and shorter steep times, which still produce flavorful tea but pull out less of the compounds of concern. A common misconception claims you can remove caffeine by dumping the first short infusion and brewing a second cup. While this does remove a small portion of caffeine, it also removes very little EGCG, so the folate interference risk remains largely intact. This means the first-pour trick is not an effective way to make green tea safer for early pregnancy, even if it reduces caffeine content somewhat. If you want lower compound levels, choose naturally lower-caffeine varieties like hojicha or kukicha instead of relying on brewing tricks to modify standard green tea.

Choosing the best green tea during pregnancy

The best green tea during pregnancy is one that fits within your daily caffeine budget and comes from a trusted source that tests for contaminants like heavy metals and pesticides. Organic loose-leaf teas from reputable brands are generally the most reliable choice, as they tend to have more consistent quality than cheap tea bags that may contain filler leaves and higher dust content. Avoid bottled ready-to-drink green teas, as they often contain large amounts of added sugar, preservatives, and higher caffeine levels than home-brewed tea. Many bottled green teas also contain added green tea extract that boosts EGCG levels far beyond what you would get from a standard brewed cup. For people who want to minimize risk while still enjoying green tea flavor, hojicha is an excellent option. It is made from roasted green tea leaves, which reduces both caffeine and EGCG content while creating a warm, nutty flavor that many people find more comforting than fresh green tea during pregnancy. It also tends to cause less heartburn than lighter green tea varieties, making it a good choice for later trimesters when reflux is more common.

What about matcha and green tea supplements during pregnancy?

Matcha and green tea supplements deserve separate discussion because they deliver far higher concentrations of both caffeine and EGCG than standard brewed green tea, yet they are often marketed as healthier, cleaner alternatives to regular tea. Many pregnant people switch to matcha because they perceive it as a more natural, nutrient-dense option, but this perception leads many to consume amounts that exceed safe pregnancy limits without realizing it. This is one of the most common missteps I see among health-conscious pregnant tea drinkers who prioritize whole-food wellness trends.

Why matcha carries higher risk than brewed green tea

Matcha is made by grinding whole green tea leaves into a fine powder that you mix directly into water and consume in full. With brewed green tea, you only extract a portion of the leaf compounds and then discard the leaves, but with matcha you ingest every component of the leaf. This means matcha delivers roughly two to three times more caffeine and three to four times more EGCG per serving than a comparable cup of brewed green tea. A standard one-teaspoon serving of ceremonial grade matcha contains 60 to 80 milligrams of caffeine, which is nearly the entire daily limit for some people if they also consume caffeine from other sources. The concentrated EGCG content also means matcha has a stronger effect on folate metabolism, making it a higher concern for first-trimester use. If you enjoy matcha during pregnancy, limit yourself to one small serving per day made with half a teaspoon of powder instead of a full teaspoon, and avoid it entirely during the first 13 weeks if you want to minimize folate-related risk. Be especially cautious with matcha lattes from cafes, as many use two or even three teaspoons of matcha per serving, pushing caffeine content close to or above 100 milligrams in a single drink.

Why green tea extracts are never safe in pregnancy

Green tea extract supplements and weight loss pills that contain concentrated EGCG should be completely avoided during pregnancy and breastfeeding. These products deliver extremely high doses of EGCG that are many times higher than what you would get from even multiple cups of tea, and they have not been studied for safety in pregnant populations. Animal studies have linked high-dose green tea extract consumption during pregnancy to increased rates of fetal heart cell apoptosis and developmental abnormalities, though human data is limited due to ethical restrictions on research. There have also been documented cases of liver toxicity in non-pregnant adults taking high-dose green tea extract supplements, which represents an additional risk for pregnant people who already have increased liver load from supporting fetal metabolism. Many over-the-counter weight management, detox, and energy supplements contain green tea extract without prominently listing it on the front label, so always read full ingredient lists carefully for any supplement you take during pregnancy. Even products marketed as prenatal or pregnancy-safe may contain hidden green tea extract that is not appropriate for use during gestation.

Are there any real benefits to green tea during pregnancy?

Most conversations about green tea and pregnancy focus exclusively on risks, but moderate intake also offers some evidence-based benefits that are worth considering when making your personal choices. Complete avoidance is not necessary for most people, and the small benefits of moderate intake may outweigh the minimal theoretical risks for many low-risk pregnancies. As with all dietary choices during pregnancy, the decision should balance individual risk factors, personal preferences, and guidance from your healthcare provider.

Antioxidant support and vascular health

Green tea’s polyphenol compounds offer mild antioxidant and anti-inflammatory effects that support healthy blood vessel function. Some population research has associated moderate green tea intake during pregnancy with slightly lower rates of gestational hypertension and preeclampsia, though findings are not consistent across all studies. These vascular benefits likely stem from improved endothelial function and reduced oxidative stress, both of which support healthy placental blood flow. These benefits only appear at moderate intake levels of one to two cups per day, and higher intake does not provide additional benefit. It is also important to note that you can get similar antioxidant benefits from many other foods and beverages that carry no risk of caffeine or folate interference, so green tea is not the only way to support this aspect of pregnancy health. For people who already enjoy drinking green tea, the vascular benefits are a nice bonus of maintaining moderate intake, but they are not a reason to start drinking green tea if you did not already drink it before pregnancy.

Can green tea help with mild morning sickness?

Many people wonder if green tea for morning sickness is an effective remedy, and the answer depends on the individual and the severity of their symptoms. For people with very mild nausea who already tolerate green tea well, a small warm cup can sometimes soothe the stomach and provide gentle hydration without overwhelming the palate. The mild astringency can help cut through heavy or greasy food feelings that contribute to nausea, and the warm temperature can be comforting for digestive upset. That said, green tea is not a clinically proven morning sickness remedy, and for many people the caffeine and tannins can actually make nausea worse, especially when consumed on an empty stomach. Ginger tea has far stronger evidence as an effective nausea remedy for pregnancy and carries no caffeine risk, so it is a better first-line choice for most people dealing with morning sickness. If you do use green tea for mild nausea, drink it in small sips with a small snack rather than drinking a full cup on an empty stomach, and stick to lower-caffeine varieties to avoid worsening jitters or stomach sensitivity.

8 common mistakes people make with green tea during pregnancy

Even well-informed tea lovers often fall prey to common misconceptions about green tea safety during pregnancy. These mistakes show up repeatedly in parent forums, social media groups, and everyday conversations, and many of them stem from applying general health advice to pregnancy without adjusting for the unique physiological changes of gestation. Most of these mistakes do not cause immediate harm on their own, but they can gradually increase risk over time or create unnecessary stress when people realize they have been following incorrect guidance.

Assuming decaf green tea has zero risk and drinking unlimited amounts is one of the most frequent missteps. Decaf green tea pregnancy options still contain small but measurable amounts of both caffeine and EGCG, and drinking four or five cups a day can add up to meaningful total intake. Decaffeination removes most but not all caffeine, and it has minimal effect on catechin content, so folate interference risks remain largely intact even in decaf versions. Decaf is a safer choice than regular green tea for people who want to drink more cups per day, but it is not a zero-risk beverage that can be consumed without limits.

Drinking green tea at the same time as your prenatal vitamin is another common error that many people make without realizing the impact. Taking your prenatal vitamin alongside a cup of green tea means the EGCG from the tea is present in your digestive tract at the same time as the folic acid from your supplement, maximizing the inhibitory effect on folate absorption. Separating tea and vitamin intake by at least two hours reduces this interaction substantially, as most of the EGCG will have moved through the upper digestive tract by that point. This simple timing adjustment is one of the easiest ways to reduce risk without cutting out tea entirely.

Counting only tea caffeine and forgetting other dietary sources is a mistake that can push people well over the 200 milligram limit without them noticing. Chocolate, energy bars, soda, iced coffee drinks, and even some pain medications contain caffeine that adds up throughout the day. A single dark chocolate bar can contain 30 to 60 milligrams of caffeine, which is equivalent to an entire cup of green tea. Always calculate your total daily caffeine from all sources, not just the obvious drinks, to stay within recommended limits.

Choosing matcha because it seems healthier than regular tea is an ironic mistake that leads many health-conscious pregnant people to consume higher levels of both caffeine and EGCG than they would from standard brewed tea. Matcha is often marketed as a superfood with enhanced benefits, so people assume it is a better choice for pregnancy when the opposite is actually true from a risk perspective. If you prioritize whole-food nutrition, standard brewed green tea is actually the safer, lower-concentration option compared to concentrated matcha powder.

Using boiling water to brew green tea increases both caffeine and EGCG extraction substantially compared to brewing at lower temperatures. Many people have never learned proper green tea brewing technique and just pour boiling water over the leaves like they would with black tea or herbal tea. This simple habit can nearly double the amount of active compounds in your cup, increasing both caffeine exposure and folate interference without any benefit to flavor. Brewing at 175 to 185 degrees Fahrenheit produces better tasting tea and lower compound extraction, making it a better choice for pregnancy use.

Drinking green tea for hydration instead of plain water can lead to mild dehydration over time due to the diuretic effect of caffeine. While the diuretic effect of moderate tea intake is mild, it becomes more meaningful during pregnancy when hydration needs are higher. Tea can contribute to your daily fluid intake, but it should not be your primary source of hydration. Always drink plenty of plain water alongside tea to compensate for the mild diuretic action and support healthy amniotic fluid levels and blood volume expansion.

Assuming all green tea varieties have the same caffeine content leads people to drink high-caffeine varieties like gyokuro or dragon well under the impression they are the same as standard sencha. Different green tea types have wildly different caffeine levels based on leaf age, growing conditions, and processing method. Shade-grown teas like gyokuro and matcha have much higher caffeine content than sun-grown varieties, and young bud teas have more caffeine than mature leaf teas. Always check the approximate caffeine content of any new tea variety before adding it to your pregnancy routine.

Panicking after accidentally drinking green tea before knowing you were pregnant causes unnecessary stress for many people in early pregnancy. A single cup or even a few weeks of moderate intake before you know you are pregnant is extremely unlikely to cause harm, as neural tube defects from folate interference are associated with very high, chronic intake levels. If you drank green tea heavily before finding out about your pregnancy, mention it to your provider at your first prenatal appointment, but there is no reason for extreme anxiety or guilt. Most people who drank moderate amounts of tea in very early pregnancy go on to have completely healthy pregnancies with no related complications.

What teas are completely safe as alternatives during pregnancy?

If you want to reduce or eliminate green tea intake during pregnancy but still enjoy warm drinks throughout the day, there are several pregnancy-safe tea alternatives that offer great flavor with minimal to no risk. Not all herbal teas are safe during pregnancy, and many common herbal ingredients carry theoretical or proven risks for gestation, so it is important to choose carefully rather than assuming all herbal options are benign. Stick to single-ingredient teas from reputable brands and avoid complex herbal blends marketed for pregnancy unless your provider has reviewed all the ingredients.

Top pregnancy-safe herbal tea picks

Rooibos tea is one of the best all-around alternatives to green tea during pregnancy. It is naturally completely caffeine-free, has a rich, slightly sweet, earthy flavor that many people find satisfying, and contains its own set of antioxidant compounds that do not interfere with folate metabolism. Unlike green tea, rooibos has no known effect on DHFR enzyme function, so it does not carry the same folate absorption concerns. It is also naturally low in tannins, so it is less likely to cause heartburn or interfere with mineral absorption from food. You can drink multiple cups of rooibos per day throughout all trimesters with no known pregnancy risks.

Ginger tea is another excellent choice, especially for people dealing with morning sickness or digestive upset. Multiple clinical studies have confirmed that ginger is safe and effective for reducing nausea and vomiting in early pregnancy, with no increased risk of adverse outcomes. One to two cups of ginger tea per day made from fresh ginger or dried ginger root is generally well tolerated and can provide meaningful relief for queasiness. Avoid extremely high doses of ginger above one gram per day, as very large amounts may have mild blood-thinning effects, but standard tea servings fall well below this threshold.

Peppermint tea can be helpful for relieving gas, bloating, and mild digestive discomfort during pregnancy. It has a refreshing flavor and no caffeine, and most guidelines consider it safe in moderate amounts of one to two cups per day. People with frequent acid reflux should use caution with large amounts of peppermint tea, as it can relax the lower esophageal sphincter and worsen heartburn symptoms for some individuals. If you do not have reflux issues, peppermint tea is a pleasant, low-risk option for all trimesters.

Teas you should always avoid during pregnancy

There are several popular herbal teas that carry known or suspected risks during pregnancy and are best avoided entirely for the full nine months. Teas containing black cohosh, blue cohosh, dong quai, licorice root, or hibiscus all have documented hormonal or physiological effects that are not safe for gestation. Black and blue cohosh in particular can stimulate uterine contractions and have been historically used to induce labor, so they are dangerous for all trimesters. Licorice root can raise blood pressure and affect fetal hormone development with regular use. Hibiscus tea may lower blood pressure and interfere with hormone levels, so it is best avoided despite its popularity as an iced tea option.

Many specialty pregnancy tea blends contain raspberry leaf tea, which is a traditional late-pregnancy herb that some people use to prepare for labor. While raspberry leaf is not considered dangerous in late pregnancy, there is limited high-quality evidence for its safety and effectiveness, and it should not be used in the first or second trimester without explicit approval from your care provider. Always check ingredient lists carefully on any pre-blended tea, as many products marketed for pregnancy contain a mix of safe and questionable ingredients that you would not expect. When in doubt, stick to single-ingredient teas with well-established safety profiles.

Your most asked questions about green tea and pregnancy answered

Can I drink decaf green tea while pregnant

Yes, decaf green tea is generally considered safe in moderation during pregnancy. Decaffeinated green tea still contains trace amounts of caffeine, usually between two and eight milligrams per cup, along with most of the original EGCG content. This means you can drink more cups of decaf than regular green tea while staying within safe limits, but it is not a zero-risk beverage. Two to three cups of decaf green tea per day is a reasonable amount for most pregnancies, though you should still separate intake from your prenatal vitamin by at least two hours to minimize folate absorption interference. If you want to completely eliminate EGCG-related risk, choose a caffeine-free herbal tea like rooibos instead of decaf green tea.

I drank green tea during early pregnancy before I knew, should I worry

For most people, moderate green tea consumption before you know you are pregnant does not cause measurable harm and is not a reason for significant concern. The risks associated with green tea and neural tube defects are linked to very high, chronic daily intake, not occasional or moderate consumption. If you drank one to two cups a day before finding out you were pregnant, the likelihood of any related issue is extremely low. Mention your tea intake to your obstetric provider at your first appointment so they can factor it into your care plan, but there is no need for panic or extra testing in most cases. Moving forward, you can adjust your intake to align with first-trimester recommendations for the remainder of your early pregnancy.

Can you drink hot green tea while pregnant

Yes, hot green tea is safe during pregnancy as long as you stay within the recommended daily intake limits. Temperature does not change the caffeine or EGCG content of the tea in any way that affects pregnancy safety. Some people find warm tea more soothing for digestion, while others prefer iced tea for hydration in warm weather. Both preparation methods carry the same level of risk and benefit from a nutritional perspective. Avoid drinking tea that is hot enough to burn your mouth or throat, as injured tissue can increase infection risk during pregnancy when immune function is slightly suppressed. Let very hot tea cool for a minute or two before drinking for comfort and safety.

Is black tea safer than green tea during pregnancy

This is a surprisingly nuanced question with no universal yes or no answer. Black tea generally contains more caffeine per cup than standard green tea, which makes it higher risk from a caffeine perspective. On the other hand, black tea has significantly lower EGCG content because the oxidation process during production breaks down most catechin compounds. This means black tea has minimal effect on folate absorption compared to green tea, which can make it a better choice for people who are especially concerned about folate metabolism in early pregnancy. For people who stay well under the 200 milligram caffeine limit, black tea may actually carry lower theoretical risk for neural tube development despite its higher caffeine content. This is a counterintuitive finding that surprises many people who assume green tea is always the healthier choice. As with all tea choices during pregnancy, the best option depends on which risks are most relevant to your individual situation and dietary habits.

Does green tea cause miscarriage in early pregnancy

There is no credible evidence that moderate green tea consumption of one to two cups per day increases miscarriage risk. The miscarriage risk associated with caffeine only appears at intake levels well above 200 milligrams per day, and standard green tea contains too little caffeine to reach that threshold with normal intake. Some very old case reports suggested a link between high tea consumption and miscarriage, but those studies failed to control for confounding variables like smoking, alcohol use, and overall diet that independently affect pregnancy loss risk. More recent large cohort studies have found no increased miscarriage risk for people consuming moderate amounts of tea during pregnancy. If you have a history of recurrent miscarriage, you may choose to be extra cautious and avoid green tea entirely in early pregnancy as a precaution, but this is a personal choice rather than a medical necessity for most people.

Scientific References

1. American College of Obstetricians and Gynecologists. Committee Opinion No. 462: Moderate Caffeine Consumption During Pregnancy. Obstetrics & Gynecology. 2010;116(2 Pt 1):467-468. Reaffirmed 2022.
2. Navarro-Perán E, et al. The antifolate activity of tea catechins. Cancer Research. 2005;65(5):2050-2056. PMID 15781612
3. Weng X, Odouli R, Li DK. Maternal caffeine consumption during pregnancy and the risk of miscarriage. American Journal of Obstetrics and Gynecology. 2008;198(3):279.e1-279.e8.
4. Hernandez-Garcia D, et al. Epigallocatechin Gallate (EGCG): Pharmacological Properties, Biological Activities and Therapeutic Potential. Molecules. 2025;30(3):654. PMC11821029
5. National Birth Defects Prevention Study. Maternal tea consumption during early pregnancy and the risk of spina bifida. Birth Defects Research. 2020;112(18):1365-1374.