Eating and nutrition

• It’s important to eat healthy foods during pregnancy.
• Most pregnant women need around 300 extra calories per day.
• Take a prenatal vitamin every day.

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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. The main source of caffeine for most adults is coffee.

The March of Dimes recommends that women who are pregnant or trying to become pregnant consume no more than 200 milligrams (mg) of caffeine per day. This is the amount of caffeine in about one 12-ounce cup of coffee.

Some studies suggest that larger amounts of caffeine may contribute to fertility problems or miscarriage. The source of the caffeine does not matter; the risk is the same for caffeine from coffee, tea, sodas and other foods and drinks. Women should be aware of which foods and drinks contain caffeine so they can limit their intake when they are pregnant or trying to become pregnant.

What foods and drinks contain caffeine?
Caffeine is found in:

• Coffee and coffee-flavored products, like yogurt and ice cream
• Tea
• Some soft drinks
• Chocolate and chocolate products, like chocolate syrup and hot cocoa

The amount of caffeine in foods and drinks varies a lot. For coffee and tea, the brand, how it is prepared, the type of beans or leaves used, and the style of serving (espresso, latte and others) affect the amount of caffeine. See the table below for a list of foods and drinks and the amount of caffeine they contain. The amounts listed are averages, so they may change depending on brand or how the food or drink is made.

What medicines contain caffeine?
Some medicines used for pain relief, migraines, colds and delaying sleep contain caffeine. The Food and Drug Administration (FDA) requires that the labels of medications list the amount of caffeine they contain. Pregnant women should not take medications that contain caffeine unless they talk to their health care provider first. They should check with their health care provider before taking any medication (including over-the-counter medicines) during pregnancy.

Some herbal products, such as guarana, yerba mate, kola nut and green tea extract, contain caffeine ⁽²⁾. The FDA does not require that herbal products carry a label saying how much caffeine they contain, so amounts can vary greatly. A recent government study found that the above products contained as much caffeine as 1 to 8 cups of coffee⁽²⁾. Pregnant women should not use herbal products because their safety in pregnancy has not been studied.

How does caffeine affect the body?
Caffeine is a stimulant that increases alertness. It slightly increases blood pressure and heart rate and the amount of urine the body makes.

Some people are more sensitive to caffeine than others. Pregnant women may be especially sensitive to it because they take longer to clear caffeine from the body than people who are not pregnant ⁽³⁾. Caffeine may cause some people to feel jittery, have indigestion or have trouble sleeping.

During pregnancy, caffeine crosses the placenta and reaches the baby. Caffeine may decrease blood flow to the placenta, which may harm the baby⁽³⁾.

Does caffeine contribute to miscarriage?
There have been many studies on caffeine and miscarriage, but the results have been conflicting. For example, two studies came out in January 2008.

• One found that women who consume 200 mg or more of caffeine daily are twice as likely to have a miscarriage as women who consume no caffeine (25 percent vs. 12.5 percent) ⁽³⁾.
• The other found no increased risk among women who drank modest amounts of coffee daily (between about 200 mg/day and 350 mg/day) ⁽⁴⁾.

Earlier studies found that only women who consume large amounts of caffeine (500 mg a day or more) are more likely to miscarry ^{(5, 6)}. However, until more is known about the risks of caffeine in pregnancy, the March of Dimes recommends a cautious approach: Pregnant women should limit caffeine to less than 200 mg a day.

Does caffeine contribute to other pregnancy complications?
A 2003 Danish study suggested that women who drink 4 to 7 cups of coffee a day may be at slightly increased risk of having a stillborn baby ⁽⁷⁾. But women who drank 8 or more cups a day had more than twice the risk of stillbirth as women who drank no coffee. It is not proven that caffeine contributed to this increased risk.

Does caffeine affect fertility?
Moderate amounts of caffeine probably don’t reduce a woman’s chances of getting pregnant. Most studies have found no effect on fertility when women consume less than 300 mg of caffeine a day. However, some studies have found an association between high levels of caffeine (about 500 mg or greater) and decreases in fertility ⁽⁸⁾.

Does caffeine affect the newborn?
There are conflicting studies on whether caffeine affects a baby’s growth during pregnancy. One study found that daily consumption of small amounts of caffeine (100 mg or greater) may slightly reduce a baby’s birthweight ⁽⁹⁾. However, other studies found reduced birthweight only when mothers consumed more than 300 mg a day, and some studies found no association between caffeine and fetal growth ⁽¹⁰⁾. If caffeine does affect a baby’s birthweight, the effect is likely to be very small ^{(9, 11, 12)}.

Babies of women who consume large amounts of caffeine (more than 500 mg/day) may be more likely to have faster breathing and heart rates and to sleep less in the first few days of life ⁽¹³⁾.

Is caffeine safe during breastfeeding?
The American Academy of Pediatrics (AAP) considers it safe for a woman to consume caffeine while breastfeeding ⁽¹⁴⁾. However, a small amount of caffeine does get into breast milk, so breastfeeding women should limit caffeine. Breastfed babies of women who drink more than 2 to 3 cups of coffee a day may become irritable or have trouble sleeping ⁽¹⁴⁾. 

References

1. U.S. Department of Agriculture. (2009). National Nutrient Data Bank for Standard Reference.
2. U.S. Department of Agriculture, Agricultural Research Service. (2009). Caffeine-containing botanicals in dietary supplements. Agricultural Research.
3. Weng, X., Odouli, R. & Li, D.K. (2008). Maternal caffeine consumption during pregnancy and the risk of miscarriage: A prospective cohort study. American Journal of Obstetrics and Gynecology, 198 (3), e1-8.
4. Savitz, D.A., Chan, R.L., Herring, A.H. & Hartmann, K.E. (2008). Caffeine and miscarriage risk. Epidemiology, 19 (1), 55-62.
5. Cnattingus, S., Signorello, L.B., Anneren, G., Clausson, B., Ekbom, A., et al. (2000). Caffeine intake and the risk of first-trimester spontaneous abortion. New England Journal of Medicine, 343 (25), 1839-1845.
6. Klebanoff, M., Levine, R.J., DerSimonian, R., Clemens, J.D. & Wilkins, D.G. (1999). Maternal serum paraxanthine, a caffeine metabolite, and the risk of spontaneous abortion. New England Journal of Medicine, 341 (22), 1639-1644.
7. Wisborg, K., Kesmodel, U., Hammer Bech, B., Hedegaard, M. & Brink Henriksen, T. (2003). Maternal consumption of coffee during pregnancy and stillbirth and infant death in the first year of life: Prospective study. British Medical Journal, 326, 420-423.
8. Practice Committee of American Society for Reproductive Medicine in collaboration with Society for Reproductive Endocrinology and Infertility. (2008). Optimizing natural fertility. Fertility and Sterility, 90 (5 Suppl), S1-6.
9. CARE Study Group. (2008). Maternal caffeine intake during pregnancy and risk of fetal growth restriction: a large prospective observational study. British Medical Journal, 337 (32), a2332.
10. Bech, B.H., Obel, C., Brink Hendersen, T. & Olsen, J. (2007). Effect of reducing caffeine intake on birth weight and length of gestation: Randomized controlled trial. British Medical Journal, 334, 409-412.
11. Bracken, M.B. Association of maternal caffeine consumption with decrements in fetal growth. (2003). American Journal of Epidemiology, 157, 456-466.
12. Clausson, B., Granath, F., Ekbom, A., Lundgren, S., Nordmark, A., et al. (2002). Effect of caffeine exposure during pregnancy on birthweight and gestational age. American Journal of Epidemiology, 155 (5), 429-436.
13. Organization of Teratology Information Services (OTIS). (2008). Caffeine and pregnancy.
14. American Academy of Pediatrics, Committee on Drugs. (2001). Policy statement: The Transfer of drugs and other chemicals into human milk. Pediatrics, 108 (3), 776-789.

May 2010