I love coffee. I drink an oat milk latte nearly every single day. So I know how difficult it
is to give up this form of caffeine. And yet, I tell my patients who are trying to
conceive to stop caffeine entirely. Is that really necessary? Is a little caffeine okay
before you are pregnant? Does caffeine use before conception make it more difficult
to become pregnant? Does it increase the risk for early miscarriage? Stay tuned.
In this episode, I am focusing on people who are trying to get pregnant rather than
people who are already pregnant. I will answer two questions. Will caffeine use make it take
longer to conceive and will preconception caffeine use increase the risk for an early pregnancy loss.
To get the most accurate answers, we look for studies in which they assessed caffeine use
by doing blood testing rather than just asking people whether they consumed caffeine. Why? Some
people may not report consuming caffeine even when they do. For example, many people may not
realize that chocolate or tea contains caffeine. Some people may not remember accurately how much
caffeine they consume. A second problem is that caffeine levels in various foods and
beverages may vary widely. If a study participant states that they drink two cups of coffee a day,
what does that mean? How big is the cup? Is it cappuccino or straight coffee? How
is it brewed? All of these factors can cause the amount of caffeine to differ by a lot.
Blood testing, on the other hand, allows us to accurately determine how much caffeine is in a
person's body. After consuming caffeine, it is broken down into the body into a
few metabolites. These metabolites can be measured and studies have shown that they
accurately distinguish levels of caffeine consumption among reproductive-age women.
The second thing we look for in a study is how pregnancy was diagnosed. Blood
or urine testing for hCG is the most accurate early method to determine whether someone has
conceived. Most pregnancy losses occur very early in pregnancy often before a
person is even aware they are pregnant. I talk about that more in this episode.
The best analysis to date has come from the EAGeR Trial. This study followed over
1200 women. These were women who were actively trying to conceive and who had a history of 1 or
2 previous pregnancy losses. The initial purpose of the study was to determine the effect of daily
low dose aspirin started before conception on the miscarriage risk in women. During that
study blood was drawn before conception which was later analyzed for caffeine and its metabolites.
Okay. So what does the data say? A total of 797 women became pregnant within 6 months.
Mild to moderate caffeine consumption did not correlate with the ability to get pregnant in
a given month. Based on this, we can say that mild to moderate caffeine consumption
would not prolong the time it takes to become pregnant. We cannot say for sure
whether this holds true for high caffeine consumption because there weren't enough
people in the study who had high caffeine consumption. There have been other studies,
however, which found that high caffeine consumption lowered the ability to conceive.
There was a correlation between caffeine consumption and early pregnancy loss. In fact,
any detectable level of caffeine in the blood before conception was associated with a nearly
5 fold increase in the chance for a pregnancy to be lost after a positive pregnancy test.
Our Infertility TV Bottom line is this. If you are trying to conceive,
it is best to avoid caffeine completely. Although it doesn't seem to reduce your
ability to conceive, it is associated with a pretty large increase in early pregnancy loss