Study Links Caffeine to Fetal Growth RestrictionNov 5, 2008 | Parker Waichman LLP
The authors of a new study say that pregnant women should substantially reduce - if not eliminate completely - caffeine from their diets. The study, conducted by British researchers, found that greater caffeine consumption increased the odds of giving birth to a baby with fetal growth restriction.
Fetal growth restriction is a fetal weight that is below the 10th percentile for gestational age as determined through an ultrasound. This can also be called small-for gestational age (SGA) or intrauterine growth restriction (IUGR). The condition is caused by a variety of factors, including use of drugs, cigarettes and alcohol, as well as poor nutrition during pregnancy.
For this study, published in the journal BMJ, researchers looked at 2,600 women who gave birth at two British hospitals between 2003 and 2006. Every trimester while pregnant, the women reported their consumption of caffeinated products including tea, coffee, soft drinks, energy drinks, and chocolate. And in their first trimester, they recalled their consumption of those items in the month before conception.
Of that group, about 13 percent gave birth to a baby with fetal growth restriction. Compared to women who got less than 100 milligrams (slightly more than what is found in an 8 oz cup of coffee) of caffeine per day, the odds of having a baby with fetal growth restriction were:
- 20 percent higher for women who got 100-199 milligrams per day of caffeine
- 50 percent higher for women who got 200-299 milligrams per day of caffeine
- 40 percent higher for women who got more than 300 milligrams per day of caffeine
While the findings don't prove that caffeine is to blame for fetal growth restriction, the authors of the study do point out that caffeine can cross the placenta, passing from mother to fetus. They also speculated that the issue might not be caffeine itself, but one of the compounds that caffeine breaks down into.
Despite this study's findings, an accompanying editorial stops short of recommending that pregnant women eliminate all caffeine from their diets. The editorial points out some other studies have failed to find an association between fetal growth restriction and caffeine. The editorialist say they are concerned that advice to eliminate all caffeine may unnecessarily frighten women who have consumed caffeine while pregnant.