Caffeine

From: Exposure to Psychotropic Medications and Other Substances during Pregnancy and Lactation: A Handbook for Health Care Providers

On this page:

Summary and recommendations
Fetal effects
Neonatal effects
Long-term effects on the child
Breastfeeding
Withdrawal effects on the mother

Caffeine, the most commonly consumed stimulant in the world, is found in coffee, tea, chocolate, and some soft drinks, dietary aids, supplements and pain medications.

Summary and Recommendations

Women should be encouraged to monitor the amount of caffeine in food, drinks, supplements and pain medication throughout pregnancy, and to consume less than 150 milligrams of caffeine from all sources per day. Pregnant women consuming large amounts of caffeine should taper their use to this recommended level.

Caffeine content^1,2

Caffeine source	Amount
Coffee (8 oz / 227 mL) (many take-out coffee cup sizes are larger)	25–200 mg
Tea (8 oz / 227 mL)	40–120 mg
Cola and other soft drinks (12 oz / 341 mL)	25–75 mg
Energy drinks (17 oz / 483 mL)	100–600 mg
Chocolate (2 oz / 57 g)	10–35 mg

Fetal effects

During the first trimester, the half-life of caffeine remains at the normal rate of 2.5 to 4.5 hours. During the second and third trimesters, however, clearance is substantially delayed as the half-life extends to 10.5 hours.³

Caffeine is known to readily cross the placenta, and substantial quantities pass into the amniotic fluid and umbilical cord blood; it also appears in the urine and plasma of neonates. In addition, fetuses and neonates have low levels of the enzymes needed to metabolize caffeine, further increasing the half-life and, therefore, exposure to and possible accumulation of caffeine in their system.

Epidemiological studies⁴ have produced incomplete or conflicting results about the effects of caffeine exposure in pregnancy.

Moderate caffeine consumption in pregnancy has not been associated with premature delivery or low birth weight.^5,6 A meta-analysis suggests a small but statistically significant increase in the risk of low-birth-weight babies in pregnant women who consume more than 150 milligrams of caffeine per day.⁶

Major malformations

Moderate caffeine consumption in pregnancy is not linked to any major malformations.

Spontaneous abortion

There are no known associations between moderate caffeine consumption in pregnancy and spontaneous abortion.

A small but statistically significant increase in the risk of spontaneous abortion has been found in pregnant women consuming a daily total of more than 150 milligrams of caffeine.⁶ This conclusion is also supported by a study that found that extremely high levels of caffeine metabolite were associated with spontaneous abortion.⁷

Neonatal effects

In a small study, the newborns of women who consumed more than 500 milligrams of caffeine each day while pregnant showed cardiac arrhythmias, fine tremors and tachypnea.⁸

Long-term effects on the child

There are no reports of long-term effects on children due to in utero exposure to caffeine.

Breastfeeding

Caffeine is excreted into breast milk and reaches peak levels within one hour of maternal consumption; however, the amount of caffeine in breast milk is usually too low to show any significant effects. Nevertheless, large amounts of caffeine may accumulate and cause irritability and poor sleeping patterns in the baby.⁹

Withdrawal effects on the mother

Caffeine withdrawal symptoms can include headache, drowsiness, fatigue, decreased alertness, nausea and agitation.

References

Center for Science in the Public Interest. (n.d.). Caffeine Content of Food and Drugs. Washington, DC: Author. Available: www.cspinet.org/reports/caffeine.pdf. Accessed July 11, 2007.
Mayo Clinic. (2005). Caffeine Content of Common Beverages. Available: www.mayoclinic.com/health/caffeine/AN01211. Accessed July 11, 2007.
Knutti, R., Rothweiler, H. & Schlatter, C. (1982). The effect of pregnancy on the pharmacokinetics of caffeine. Archives of Toxicology. Supplement, 5, 187–192.
Koren, G. (2000). Caffeine during pregnancy? In moderation. Canadian Family Physician, 46, 801–803.
Linn, S., Schoenbaum, S.C., Monson, R.R., Rosner, B., Stubblefield, P.G. & Ryan, K.J. (1982). No association between coffee consumption and adverse outcomes of pregnancy. New England Journal of Medicine, 306 (3), 141–145.
Fernandes, O., Shabarwal, M., Smiley, T., Pastuszak, A., Koren, G. & Einarson, T. (1998). Moderate to heavy caffeine consumption during pregnancy and relationship to spontaneous abortion and abnormal fetal growth: A meta-analysis. Reproductive Toxicology, 12 (4), 435–444.
Klebanoff, M.A., Levine, R.J., Der Simonian, 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.
Hadeed, A. & Siegel, S. (1993). Newborn cardiac arrhythmias associated with maternal caffeine use during pregnancy. Clinical Pediatrics, 32 (1), 45–47.
Hill, R.M., Craig, J.P., Chaney, M.D., Tennyson, L.M. & McCulley, L.B. (1977). Utilization of over-the-counter drugs during pregnancy. Clinical Obstetrics and Gynecology, 20 (2), 381–394.