HealthDay News — Even moderate daily caffeine intake during pregnancy may lead to smaller birth size, according to a study published online March 25 in JAMA Network Open.
Jessica L. Gleason, Ph.D., from the U.S. National Institutes of Health in Bethesda, Maryland, and colleagues evaluated the association between maternal caffeine intake and neonatal anthropometry by fast or slow caffeine metabolism genotype. The study was a secondary analysis of data for 2,055 nonsmoking women (mean age, 28.3 years) at low risk for fetal growth abnormalities, who had complete information on caffeine consumption, from 12 U.S. clinical sites for a cohort study that assessed fetal growth (2009 to 2013).
The researchers found that compared with the first quartile of plasma caffeine level (≤28 ng/mL), neonates of women in the fourth quartile (>659 ng/mL) had lower birth weight (β = −84.3 g) and length (β = −0.44 cm), as well as smaller head (β = −0.28 cm), arm (β = −0.25 cm), and thigh (β = −0.29 cm) circumference. Women who consumed more than 50 mg of caffeine per day (the amount in about half a cup of coffee) had neonates with lower birth weight, smaller arm and thigh circumference, and smaller anterior thigh skin fold compared with women who reported drinking no caffeinated beverages. Results were similar for fast or slow caffeine metabolism genotype.
“Findings suggest that caffeine consumption during pregnancy, even at levels much lower than the recommended 200 mg per day of caffeine, are associated with decreased fetal growth,” the authors write.