Caffeine is a stimulant found in many foods, drinks and some medications. Caffeine is naturally produced by a variety of plants and is added to some foods and drinks for flavor.
Although most studies show that caffeine intake in moderation is OK, there are others that show that caffeine intake may be related to miscarriages. Avoid caffeine during the first trimester to reduce the likelihood of a miscarriage. As a general rule, caffeine should be limited to fewer than 300 mg per day during pregnancy. Caffeine is a diuretic, which means it helps eliminate fluids from the body. This can result in water and calcium loss. It is important that you are drinking plenty of water, juice, and milk rather than caffeinated beverages. Some research shows that large amounts of caffeine are associated with miscarriage, premature birth, low birth weight, and withdrawal symptoms in infants. The safest thing is to refrain from consuming caffeine.
Caffeine consumption has been associated with fetal growth restriction in some, but not all, previous research. This heterogeneity of results may be in part because of failure to account for differences among individual women in the metabolism of caffeine. The researchers of the current study review this subject.
Caffeine Absorption
Caffeine is rapidly absorbed from the gastrointestinal tract and freely crosses the placenta. Caffeine has been associated with a 25% reduction in intervillous blood flow. Although caffeine is metabolized by cytochrome P450 1A2 in adults, the fetus lacks this enzyme. Therefore, the amount of caffeine exposure to the fetus depends on the mother’s enzyme activity, which can be highly variable between individuals.
The current study accounts for caffeine metabolism as well as for multiple potential sources of caffeine intake in its examination of the effects of caffeine on fetal growth
In 2008, two studies on the effects of caffeine related to miscarriage showed significantly different outcomes. In one study released by the American Journal of Obstetrics and Gynecology, it was found that women who consume 200mg or more of caffeine daily, are twice as likely to have a miscarriage as those who do not consume any caffeine.
In another study released by Epidemiology, there was no increased risk in women who drank a minimal amount of coffee daily ( between 200-350mg per day.)
Due to conflicting conclusions from numerous studies, the March of Dimes states that until more conclusive studies are done, pregnant women should limit caffeine intake to less than 200 mg per day. This is equal to about one 12 oz cup of coffee.
It has also been shown that absorption of caffeine has a vasoconstrictive effect on placental circulation. Blood flow is not modified in the umbilical fetal vein but intervillious placental blood flow is significantly diminished after absorption of 2 cups of coffee. This decrease in blood flow along with increased concentration of noradrenaline induced by caffeine in the maternal serum could represent a potential risk for the fetus.
More about caffeine during pregnancy
Learn more about caffeine during pregnancy from the March of Dimes.
