High levels of paraxanthine, a caffeine metabolite, have been linked with reduced foetal size by researchers writing in the January 1st issue of the American Journal of Epidemiology.
Dr. Mark. A. Klebanoff led a team of researchers at the National Institutes of Health, Bethesda, Maryland, investigating whether third-trimester serum concentrations of paraxanthine were associated with delivery of infants who were considered small for their gestational age.
The researchers examined serum samples from 2,515 women who had given birth over a seven period of study. Some 222 of the children born during the period were considered to be small-for-gestational age.
What Klebanoff and his team discovered was that mothers of such small infants had significantly higher (p = 0.02) mean levels of paraxanthine (754 ng/mL) than did the other mothers (653 ng/mL). There was an even greater risk of foetal underdevelopment for mothers who also smoked.
Allowing for other factors such as maternal weight, ethnicity, and number of cigarettes smoked did not prompt a substantial change in the relationship, the researchers found.