Content table
Caffeine. For some of us, it is our lifeblood. We couldn’t possibly imagine making it through the day without a cup of joe (or five) to boost us.
But have you thought about how your caffeine habit may affect your body, particularly when it comes to trying to conceive?
Does caffeine affect fertility? Let’s find out. You’ll know whether to stop drinking caffeine or whether it’s safe to keep sipping. Here’s the quick answer, but keep reading for all the deets.
TLDR: Caffeine in moderation is A-okay while trying to conceive. And by “moderation,” we mean less than 200-300 mg per day.
The typical 8-ounce cup of brewed coffee contains about 130 mg of caffeine. So, if you’re curious about how much caffeine while TTC, keep your daily caffeine intake to no more than 2 cups of coffee.
And if you’re already pregnant, you also want to watch your caffeine consumption. That’s because studies show that pregnant women’s bodies take anywhere from 1.5-3.5 times longer to eliminate caffeine.
Why? Because of a reduction in the enzyme activity of cytochrome P450 1A2. This reduction means that small amounts of caffeine stay in a pregnant woman’s body longer than in non-pregnant people.
Speaking of caffeine staying in the body …
How is caffeine metabolized in the body?
The process of drinking coffee looks like this:
- 45 minutes after drinking that cup of buzz brew: 99% of the caffeine has been absorbed by blood and tissues – 20% in the stomach, and the rest in your small intestine.
- 15-120 minutes after consumption: You reach peak blood concentration. In addition to blood, caffeine also makes its way into other body fluids, including cerebrospinal fluid, saliva, bile, semen, breast milk, and all organs. Wild, right?
- 1.5-9.5 hours after consumption: Caffeine may remain in your body for this long, depending on various factors such as age, sex, diet, smoking, lifestyle, pregnancy status, and more.
Now let’s look more at what is going on inside your body when coffee is floating around.
For starters, caffeine is primarily metabolized in the liver by cytochrome P450 1A2, which only exists in the liver. This is where more than 90% of the caffeine you consume is metabolized.
That means your liver is working hard to process this coffee.
That caffeine is first and foremost converted to paraxanthine, which is a natural dietary ingredient.
Then, the dynamic duo of caffeine and paraxanthine work together to block the adenosine receptors in the brain.
What does this do?
It wakes you up and also affects the release of norepinephrine, dopamine, serotonin, glutamate, GABA, and more. This is likely why it feels so good to get that cup of coffee first thing in the morning.
How does caffeine affect women’s fertility?
The verdict on the connection between caffeine and fertility is still out.
Older studies came up with different results than newer studies, which can confuse things a bit.
We want to give you the whole picture, so let’s take a look at the old research versus the new on caffeine and fertility.
Older studies
A study from 1993 found that women who drank more than 300 mg of caffeine a day had a whopping 27% lower chance of conceiving for each cycle.
And those who drank less than 300 mg of caffeine a day saw a 10% reduction in their conception rates per cycle.
Another study from 1988 (clearly, this has been studied for a while) found that women who drank more than 1 cup of brewed coffee in a day were 50% less likely to conceive per cycle versus women who drank less.
But these findings have not stayed true in recent years.
Newer studies
A 2020 study found that drinking caffeine didn’t impact fertility at all. Talk about different results!
And another more recent study found that women who consumed more than 300 mg of caffeine in a day showed fertility rates that were about the same as women who drank 0-100 mg of caffeine per day.
Go figure!
To confuse things even further, the same study found that women who drank 2+ cups of tea a day were more likely to conceive than those who didn’t drink any tea. But, those who drank 3+ sodas showed to be less fertile.
It’s pretty evident that the effect of caffeine on fertility is something the research community is still trying to figure out.
How does caffeine affect pregnancy?
Now let’s talk about what happens in the body when you’re already pregnant and consume caffeine.
Caffeine runs right through the placenta with no problem. And in the process, it increases maternal catecholamine levels, which causes blood vessel constriction.
This doesn’t sound good, but what does it actually mean for the baby?
That there is a decreased blood flow to the placenta, which means fewer nutrients are transferred, which affects the growth of the fetus.
In addition to that, babies don’t have the liver enzyme we chatted about above necessary to break down caffeine. That means caffeine can accumulate in their body and result in low birth weight.
In fact, a study found that every additional 100 mg of caffeine a pregnant woman drank per day caused a linear increase in low body weight for the baby.
Ready for more?
Studies show that heavy coffee drinking (we are talking more than 300 mg of caffeine/day) before and during pregnancy meant a 68% greater risk of bleeding during early pregnancy. Makes you really second-think that second cup of coffee, doesn’t it?
Speaking of early pregnancy … A 2002 study found that the infant gestational age decreased by 3.8 and 3.5 weeks, respectively, for pregnant women who drank more than 50 mg of caffeine during their lifetime or during their first visit to the clinic. (This is when compared to women who drank 0-2 mg of caffeine a day.)
Then let’s fast forward to a 2020 study that uncovered a daily caffeine intake of 300 mg was associated with a significant risk of miscarriage. And that risk increased proportionally with 600 mg per day.
But not all studies agree. According to the American College of Obstetricians and Gynecologists, less than 200 mg of caffeine per day did not seem to increase the risk of miscarriage.
And further research found that less than 300 mg of caffeine per day (equal to 1-2 cups of coffee) was nothing to worry about.
And if you’re wondering “does caffeine affect implantation?”
We’ve got some info for you. Some animal studies show that lots of caffeine during early pregnancy could cause problems with implantation as well as fetal development. On top of that, it could create complications with pregnancy.
While that does sound scary, these findings need to be replicated in humans before we can really jump to any conclusions.
Is it safe to drink caffeine while breastfeeding?
Now that we’ve talked about caffeine while trying to conceive and caffeine while pregnant let’s talk about caffeine while breastfeeding.
Studies show that less than 1% of caffeine consumed by momma will be transferred to breast milk.
So, a cup of joe a day should not do any harm to your baby. ACOG is team 200 mg per day or less, and the CDC is team 300 mg per day or less.
Why do you want to keep your caffeine intake low while breastfeeding?
Well, because too much caffeine in a baby’s body can lead to poor sleep, (which we are guessing is the last thing you want with a newborn) as well as irritability and jitteriness.
If you start to notice your baby doing any of the above, you may want to re-evaluate your caffeine intake to save your baby (and yourself) struggles.
It’s important to note that some babies are more sensitive to caffeine than others. This means that it takes them longer to metabolize the caffeine they get via breast milk. We’re looking at you, preterm and newborns.
How does caffeine affect male fertility?
Now let’s turn it over to the guys and dive into caffeine and male fertility.
Similar to women’s fertility, the evidence with male fertility isn’t very strong and makes this a bit of a gray area.
Some studies show that caffeine doesn’t affect male fertility at all.
Other studies, however, show that the more caffeine a man drinks, the more his sperm count and quality are reduced. That’s because excess caffeine leads to oxidative stress in the body, which can damage the sperm’s DNA, which can result in infertility.
On top of that, researchers found that a man who drinks too much caffeine can actually put his partner at a higher risk of miscarriage.
So, you may want to be better safe than sorry and also keep the male’s caffeine consumption within reason while trying to conceive.
How much caffeine is in your drinks?
We’ve chatted mostly about coffee since that seems to be everyone’s caffeine of choice. But, there are other drinks that are important to mention when it comes to fertility.
Here’s a chart that breaks down how much caffeine is in one 8-ounce serving of each drink.
In addition to the drinks, you may be surprised to find that some of the snacks you’re eating also contain caffeine.
The biggest culprit is chocolate-covered coffee beans (which isn’t really a surprise, given they’re coffee beans). But they contain a massive 336 mg of caffeine per one-ounce serving!
Chocolate mousse, pie crust, chocolate candies, cookies, pudding, other candies, cereals, and frostings have anywhere from 1-4 mg of caffeine per serving.
While that doesn’t sound like a lot (especially when compared to the 336 in the chocolate-covered espresso beans!), those numbers can add up.
So this is just a friendly reminder to be aware that caffeine may be hiding and counting towards your 200-300 mg daily caffeine intake.
How to cut back on caffeine
You might not have thought about cutting back on your caffeine intake before, but the potential fertility concern could be the reason that you do now.
For starters, it’s no secret that caffeine is addictive. Cutting it cold turkey will not be easy and will likely have you craving that coffee.
Some of the most common caffeine withdrawal symptoms can include headaches, irritability, and low energy.
So, rather than setting yourself up for failure by cutting the chord, take baby steps. Start by switching over to a tea that still has some caffeine but less than you normally consume. Just be sure to consult your doctor before jumping into herbal teas.
You also probably want to avoid soda and energy drinks. This isn’t just because of their caffeine content but also because they’re usually loaded with processed sugars and chemicals that your body does not want.
Keep in mind that 200-300 mg per day is your magic range, and as long as you stay within or below that, it shouldn’t affect your fertility.
Here are some of our favorite low-to-no caffeine options to help you:
Hot cacao (cacao is the more pure version of cocoa, but either would work)
- Green tea
- Kombucha
- Golden milk turmeric “latte”
- Lemon water
- Smoothies
- Bone broth
- Coconut water
Take it with a grain of salt
Keep in mind that many factors can complicate the findings in the studies we mentioned earlier, as well as in other research you discover, regarding the connection between caffeine and fertility.
Take, for example, a study that found people who were big coffee drinkers also tended to be smokers. And obviously, smoking is not helpful when it comes to trying to conceive and pregnancy.
On top of that, these kinds of studies are mostly questionnaires and interviews rather than ones with strict objective parameters. This means they’re based on what people say, which can lead to questions with accuracy.
And, there is a lot of variation when it comes to what one person thinks is a cup of coffee versus what another person thinks is a cup of coffee in terms of size. Coffee brands vary in caffeine content too, as well as energy drinks (which we saw in the table above).
So, it’s important to be aware of all the above things, but don’t draw all of your conclusions from these studies.
Rather, you do you and what feels best to your body.
Also, take note of what your doctor says, especially if you’re trying to conceive, are pregnant, or are breastfeeding.
In review
- Does caffeine affect fertility? The connection between caffeine and fertility have mixed reviews in studies, which means the results aren’t strong conclusions.
- When it comes to caffeine while TTC, it’s safe to keep your daily caffeine intake below 200-300 mg.
- It’s important to watch your caffeine while you’re pregnant and also while breastfeeding.
- Studies show that excessive caffeine consumption may also affect male fertility, so guys – keep your caffeine numbers on the lower side, too.
- Different drinks and snacks contain varying amounts of caffeine, so keep tabs on more than just your cups of coffee.
- You can cut back your caffeine consumption by swapping out your coffee or energy drinks for alternative beverages with little to no caffeine.
- Don’t quit caffeine cold turkey, or else you may experience withdrawal symptoms.
- When it comes to caffeine intake and fertility, you do you but maybe play it safe and limit to 200 mg per day.
Was this article helpful?
- Caffeine Content in Drinks and Food | ResearchGate
- Effect of pregnancy on the pharmacokinetics of caffeine | SpringerLink
- Pharmacology of Caffeine | NIH
- Interindividual Differences in Caffeine Metabolism and Factors Driving Caffeine Consumption | Aspet
- Caffeine effects on systemic metabolism, oxidative-inflammatory pathways, and exercise performance | ScienceDirect
- Association of delayed conception with caffeine consumption | NIH
- Caffeinated beverages and decreased fertility | NIH
- Relationship between caffeine intake and infertility: a systematic review of controlled clinical studies | NIH
- Caffeinated Beverage and Soda Consumption and Time to Pregnancy | Epidemiology
- Maternal Caffeine Consumption during Pregnancy and Risk of Low Birth Weight: A Dose-Response Meta-Analysis of Observational Studies | NIH
- Maternal coffee intake and the risk of bleeding in early pregnancy: a cross-sectional analysis | BMC Pregnancy and Childbirth
- A prospective study of the effects of female and male caffeine consumption on the reproductive endpoints of IVF and gamete intra-Fallopian transfer | Oxford Academic
- Association between coffee or caffeine consumption and fecundity and fertility: a systematic review and dose–response meta-analysis | NIH
- Moderate Caffeine Consumption During Pregnancy | ACOG
- Is caffeine consumption safe during pregnancy? | NIH
- Impacts of Caffeine during Pregnancy | NIH
- Maternal food restrictions during breastfeeding | NIH
- Breastfeeding Your Baby | ACOG
- Maternal Diet | CDC
- The combination matters – distinct impact of lifestyle factors on sperm quality: a study on semen analysis of 1683 patients according to MSOME criteria | BMC
- Effect of Stress and Caffeine on Male Infertility | NIH
- Lifestyle and pregnancy loss in a contemporary cohort of women recruited before conception: The LIFE Study | Fertility and Sterility
- USDA National Nutrient Database – Caffeine | USDA
