Coffee is a common part of many people’s daily routine. Sometimes we grab a cup to get going in the morning, then maybe another in the afternoon for an energy boost. But if you’re trying to get pregnant, you may wonder if drinking coffee — or any beverage that contains caffeine — could affect fertility.
Researchers are still studying how caffeine might affect fertility, as the current research isn’t conclusive. They do know that caffeine can impact hormone levels and the reproductive system. Some effects may only occur with high doses of caffeine. Others can occur even with moderate amounts. Here’s what the research says about how caffeine could affect fertility.
It May Take Longer to Conceive With High Caffeine Intake
“The research is far from conclusive. But in women, very high caffeine intake, such as over 500 milligrams (mg) per day, has been linked to reduced fertility,” says Alex Robles, MD, a reproductive endocrinologist at Columbia University Fertility Center in New York City.
To put that in perspective, 500 mg is equivalent to about five 8-ounce cups of brewed coffee, eight cups of instant coffee, or two and a half energy shots.
Caffeine May Affect Hormone Levels
Caffeine can affect the hormones in your body that are important for conception. In men, caffeine can increase testosterone levels and affect other hormone-related proteins in the blood. It can also change how certain cells in the testicles (called Sertoli cells) function. If Sertoli cells aren’t working properly, sperm production or quality can be affected.
For women, caffeine can block certain hormone receptors, which can interfere with ovulation and the uterus’s ability to receive a fertilized egg. Caffeine may also decrease the body’s ability to convert certain hormones into estrogen, which is important for pregnancy to occur.
Caffeine May Cause Problems With Embryo Attachment
Studies in both women and mice have found that higher amounts of caffeine may make it harder for a fertilized embryo to attach to the uterine wall, says Alexander Kotlyar, MD, a board-certified reproductive endocrinologist and infertility specialist at Genesis Fertility in the New York City area.
An embryo is a fertilized egg that has begun to develop but isn’t fully formed yet. For pregnancy to continue, the embryo must attach successfully to the uterus. According to Dr. Kotlyar, even two cups of coffee a day could affect this process and lead to lower pregnancy rates.
Caffeine May Raise the Risk of Miscarriage
“Some studies show that 200 to 300 mg [of caffeine] per day may be linked to a higher risk of miscarriage,” says Dr. Robles. That’s about two to three 8-ounce cups of brewed coffee per day.
One review of studies found that for every 100 mg of caffeine consumed daily (about one cup of coffee), the risk of miscarriage increased slightly. The same review also found small increases in the risk of stillbirth, premature delivery, and having a baby with low birth weight. But these risks were relatively small, and the research findings aren’t always consistent.
Caffeine May Affect Sperm Health in Men
The research on caffeine and male fertility is mixed and much less clear than for women. “High caffeine intake has been linked to reduced sperm concentration and motility (how well sperm move), possibly affecting testosterone levels and overall sperm health in men,” says Sheeva Talebian, MD, a reproductive endocrinologist at CCRM Fertility of New York.
At least one study suggests that sperm problems may increase with higher doses of coffee, especially after more than three cups per day, says Kotlyar. “Such sperm issues also included damage to the DNA in sperm cells,” he adds.
But other studies have shown no negative effects on sperm quality, and some research even suggests caffeine might help certain cells in the testicles function better. Overall, the evidence is inconclusive, and more research is needed to understand the effects of caffeine on male fertility.
If you’re concerned about caffeine but don’t want to give up your coffee or tea completely, decaffeinated (decaf) versions might be a solution. “Decaf drinks generally appear safe for fertility. They have very small amounts of caffeine — usually under 5 mg per cup — so they don’t carry the same potential risks,” says Robles. An 8-ounce cup of decaf brewed coffee has about 1 mg of caffeine, a cup of decaf instant coffee has around 2 mg, and a decaf espresso shot has 1 mg.
Plus, there’s no strong evidence linking decaf coffee or tea to negative fertility outcomes in either men or women, adds Robles.
Still, in one study, decaffeinated coffee and tea were associated with slightly lower fertility rates in men. Other studies showed that decaffeinated soda had no effect on women’s fertility.
The reasons for these mixed findings aren’t well understood, and it’s possible that other ingredients in coffee and tea — not just caffeine — might play a role. More research is needed to better understand these results. Overall, decaf options are still considered safer than caffeinated drinks when you’re trying to conceive.
Most experts agree that one to two cups of caffeinated drinks a day appears safe when trying to conceive. “Studies suggest that 200 mg daily of caffeine (about two cups) is safe during pregnancy, and therefore, we recommend something similar when women are trying to conceive,” says Dr. Talebian.
Robles agrees, recommending that women who are trying to get pregnant should stick to under two cups of caffeine per day to reduce miscarriage risk and possibly improve fertility. “For men, similar limits are safe and reasonable,” he adds.
These recommendations align with major health organizations. The World Health Organization (WHO) and European Food Safety Authority (EFSA) advise women who are pregnant or planning to get pregnant to limit caffeine to no more than two to three cups per day to reduce the risk of miscarriage and low birthweight newborns.
Some older studies question whether or not caffeine has a negative impact on in vitro fertilization (IVF), but a recent review found no association between caffeine and IVF treatments resulting in pregnancy.
Still, caffeine affects people differently. Some people are more sensitive to caffeine. How quickly it’s processed by the body can also differ. If you’re sensitive to caffeine or notice it makes you jittery, talk to your healthcare provider and consider cutting back or avoiding it altogether, especially when trying to get pregnant.
Caffeine is one small factor to consider when thinking about fertility, says Robles. If you’re drinking one cup of coffee a day, you’re likely in the safe zone, he says. But if you’re concerned, he recommends cutting back gradually and replacing some caffeine with water or decaf.
Beware if you’re adding sweeteners or creamers to your coffee. The sugar could potentially cause weight gain or affect your blood sugar levels, especially if you have an underlying condition, such as diabetes. The spike of insulin from these coffee add-ins is similar enough to the hormones that help egg cells mature that your body could wind up with less maturing eggs, possibly even affecting ovulation. These drink sweeteners are likely not a problem if you’re drinking them in moderation, but if you use them frequently, or in combination with other added sugar sources, they could become problematic.
That said, many factors beyond caffeine can impact your ability to conceive, and most of these are things you can control. Here are some factors to pay attention to:
Weight Being underweight or overweight can affect hormone levels, which may interfere with ovulation, says Robles. Obesity can lead to a decrease in sperm count and quality in men. Aim to stay at a healthy weight through balanced eating and regular exercise. Talk to your healthcare provider if you’re unsure what a healthy weight range is for you.
Exercise Regular exercise is helpful for fertility in both men and women. But too much — especially when it leads to rapid weight loss — can delay ovulation, notes Kotlyar. Intense and excessive workouts should also be avoided, says Robles. Find a moderate exercise routine you can stick with long-term.
Diet Your diet has an impact on fertility, and this goes for both men and women. Diets high in fat can change how sperm cells work, potentially affecting a developing baby. For women, poor nutrition can interfere with ovulation and hormone balance, all of which can affect the ability to conceive. Focus on foods rich in antioxidants, folate, and omega-3s. Robles suggests following the Mediterranean diet as a good starting point.
Smoking Tobacco can affect egg and sperm quality, and it can damage the fallopian tubes, increasing the risk of ectopic pregnancy, says Kotlyar. An ectopic pregnancy is when a fertilized egg implants outside the uterus, and can be life-threatening if not treated. Smoking can also lower sperm count, affect sperm shape and movement, and increase DNA damage. If you smoke, quitting is one of the best things you can do for your fertility and your health.
Alcohol Consumption Heavy alcohol use can decrease fertility in both men and women. For men, excess drinking may also lead to weight gain, which, Kotlyar notes, can negatively affect sperm production. Avoid drinking any amount of alcohol while trying to conceive.
Stress Excessive and long-term stress can affect ovulation and sperm production. “This does not mean that any stressful period could lead to fertility issues. Rather, high stress can, over time, affect sperm production,” Kotlyar says. Find healthy ways to manage stress, like meditation, yoga, and regular exercise.
Poor Sleep When you don’t sleep well, your body produces stress hormones that can interfere with ovulation in women and reduce sperm quality in men.Poor sleep can also cause irregular menstrual cycles and may weaken your immune system in ways that make it harder to get pregnant. Aim for seven to nine hours of quality sleep each night and try to maintain a consistent sleep schedule.
Environmental Toxins A common concern when it comes to fertility is plastics, especially those containing bisphenol A (BPA), says Robles. BPA is a chemical that can interfere with your body’s hormones. Other environmental toxins include lead in water, and chemicals called phthalates, found in personal care products like shampoos and lotions. Try to use glass or stainless steel containers for food and drinks, choose personal care products without phthalates, and filter your drinking water when possible.
Testosterone Supplements “Testosterone shots may seem like a quick fix for symptoms like low energy or low libido. But for men trying to conceive, they can actually be counterproductive,” explains Talebian. When you take testosterone through shots or supplements, it only increases the testosterone in your blood, not in the testicles where sperm is made. When your body senses that you have enough (from testosterone therapy), it shuts down testosterone production, which is needed for sperm production. If you’re considering testosterone replacement therapy and want to start a family, talk to your healthcare provider about your options.
The timing depends mainly on your age and health history. If you’re under 35, most experts recommend seeing a fertility specialist after trying to conceive for 12 months without success.
“For women 35 and older, we generally recommend consultation at six months,” says Talebian. And for women over 40, that timeline shortens to two to three months. “As women get older, egg quality begins to decline, so it’s important to see a fertility specialist sooner rather than later to assess your reproductive health,” she says.
But see a fertility specialist immediately if you have known fertility issues, regardless of how long you’ve been trying. This includes irregular menstrual cycles, heavy bleeding, pelvic pain, a history of miscarriage, or endometriosis, says Robles.
For men, Talebian recommends seeing a fertility specialist if you have a history of testicular trauma, cancer, surgery in the genital area, or a family history of infertility.
Drinking excessive amounts of caffeine may affect fertility, but the findings are inconclusive, and more research is needed.
Caffeine can interfere with hormone levels, how a fertilized egg attaches to the uterus, and ovulation in women. In men, high caffeine intake may impact sperm quality, but the evidence is much less clear.
Most experts agree that one to two cups of caffeinated drinks per day are safe when trying to conceive. Decaffeinated beverages may be good substitutes.
Lifestyle factors like weight, diet, sleep, and stress can also affect fertility. Consider seeing a fertility specialist if you’ve been trying to conceive without success, especially if you’re over age 35, have irregular cycles, or have other reproductive health issues.
