A morning cup of coffee or tea is practically a tradition in the Western world. Many people are therefore interested in research looking at a possible connection between caffeine, fertility, and miscarriage rates. For people hoping to boost their natural fertility, giving up caffeine could be a doable goal. That said, some people would find it difficult to get through the day without a caffeine boost. They might have feelings of guilt and worry if they are trying to get pregnant and are concerned that caffeine could be affecting their chances. Here’s what the research says about caffeine and fertility, as well as some of the recommendations for daily caffeine intake if you’re hoping to get pregnant.
Research on Caffeine and Fertility
The worry over caffeine and fertility started after a 1988 study reported that women who drank about a cup of coffee per day were half as likely to conceive. While the study has been frequently cited in the last several decades, no subsequent study has been able to replicate those findings. One of the largest prospective studies on the subject included just over 3,000 Danish women. Researchers looked at fertility rates in relation to coffee, tea, and soda intake. The result of the study found that:
Women who consumed more than 300 mg of caffeine per day (more than 1 cup of coffee) had similar fertility rates compared to women who drank less than 100 mg to none per day.Women who drank two or more servings of tea per day were slightly more likely to conceive than those who drank no tea.Women who drank soda were less likely to conceive in any given month than women who didn’t drink soda. Women who drank three servings of soda per day had worse fertility rates than women who drank one soda serving per day.
You might be wondering if these findings suggest that you should start drinking tea to conceive faster or completely cut out soft drinks. But it’s more complicated than that. Another study published in 2017 gathered data from published research papers to look at the potential dose-related effect of caffeine or coffee on time to pregnant for both couples trying to conceive naturally and couples undergoing fertility treatment. They also looked at the risk for miscarriage based on how many milligrams of caffeine was consumed. The study’s results showed that:
Drinking 300 mg of caffeine increased the risk of early pregnancy loss or spontaneous abortion (SAB).Drinking 600 mg of caffeine more than doubled the risk of miscarriage.Caffeine did not, however, impact the time it took for couples trying to conceive naturally to get pregnant.Caffeine intake also did not seem to negatively impact pregnancy rates for couples receiving fertility treatments.
Is Caffeine the Real Problem?
Studying the impact lifestyle choices have on fertility is complex. You can’t exactly take a bunch of people, keep them in a lab to control everything they eat and drink, and see how quickly they conceive. Studies rely on accurate reporting and recall. Research on fertility rates and caffeine often ask women to report how much coffee they drank before they conceived. However, even studies such as these would pose potential issues. For example, these studies may exclude women who conceived quickly and thus never had a chance to “try to get pregnant.” Another problem with caffeine studies is the dosages aren’t always consistent. A cup of coffee you make at home can have a completely different caffeine content than a latte from your local coffee shop. Even the exact same beverage at different coffee shops can have varying amounts of caffeine. Something else to keep in mind when looking at the research on caffeine is that it’s not clear whether it’s the caffeine that can lead to problems with fertility or if there are other related lifestyle choices or habits that might be more likely to affect fertility. For example, people who smoke are more likely to drink a lot of coffee and alcoholic beverages. This could, in part, provide some explanation as to why earlier studies found strong negative fertility effects. Heavy coffee drinkers might also be smokers—and we do know that smoking hurts fertility.
Know How Much You Consume
If you want to play it safe with caffeine, taking in no more than 200 to 300 mg of caffeine a day (ideally, 100 mg or less) is recommended. This is what reproductive endocrinologists currently recommend to couples struggling to conceive. However, most of us don’t think of our caffeine fix in terms of milligrams. We think in cups. How much caffeine is in a cup of coffee or tea? How about soft drinks or energy drinks? Here are some general guidelines. Coffee
Brewed (8 oz.) = 95 to 200 mgBrewed, single-serve variety = 55 to 150 mgBrewed, decaffeinated (8 oz.) = 1 to 25 mgRegular instant (8 oz.) = 27 to 173 mgDecaffeinated instant (8 oz.) = 2 to 12 mgExpresso (1 -2 oz.) = 47 to 75 mgStarbucks grande Caffé Latte (16 oz.) = 150 mgStarbucks grande Dark Roast (16 oz.) = 240 mgStarbucks grande Cold Brew (16 oz.) = 280 mg
Tea
Black tea, brewed (8 oz.) = 40-60 mgBlack tea, decaffeinated (8 oz.) = <5 mgInstant (8 oz.) = 5 mgBottled ready-to-drink (8 oz.) = 5 to 68 mg
Soft Drinks
Coke (16 oz.) = 45 mgPepsi (16 oz.) = 45 mgDr. Pepper (12 oz.) = 41 mgMountain Dew, regular (12 oz.) = 54 mgMountain Dew MDX (12 oz.) = 71 mgJolt cola (12 oz.) = 120 mg
Energy Drinks
5-hour Energy (2 oz.) = 215 mgMonster Energy (24 oz.) = 276 mgRed Bull (12 oz.) = 111 mgSpike Shooter (8.4 oz.) = 300 mg
Cocoa, Chocolate, and Ice Cream
Cocoa from mix (8 oz.) = 5 mgMilk chocolate (1.55 oz.) = 9 mgHershey’s Special Dark Chocolate (1.45 oz.) = 31 mgBen & Jerry’s Coffee Ice Cream (4 oz.) = 45 mg
A Word From Verywell
Studies have not found a definitive connection between caffeine and lowered fertility in men. While the current research does not clearly show a negative impact on fertility in women, the studies that have shown an effect find that less than 200 mg of caffeine does not present problems for most people. However, excessive caffeine might increase your risk of early miscarriage. If you’re trying to get pregnant, you don’t necessarily have to completely give up your morning cup of coffee and you don’t need to feel guilty about it. The standard recommendation at most fertility clinics and from many OB-GYNs is to stick to one small cup of coffee a day.
