Caffeine consumption during pregnancy is not associated with pre-term birth

The notion that caffeine consumption during pregnancy is a risk factor for pre-term birth does not hold up in an extensive meta-analysis published in the American Journal of Clinical Nutrition. The authors state:

"The effect of caffeine intake during pregnancy on the risk of preterm delivery has been studied for the past 3 decades with inconsistent results...We performed a meta-analysis examining the association between caffeine consumption during pregnancy and risk of preterm birth."

They identified 15 cohort and 7 case-control studies that met inclusion criteria among MEDLINE and EMBASE articles published between 1966 and July 2010. What did the data show?

"The combined odds ratios (ORs) obtained by using fixed-effects models for cohort studies were 1.11, 1.10, and 1.08 for risk of preterm birth comparing the highest with the lowest level of caffeine intake (or no intake)during the first, second, and third trimesters, respectively. Results for the case-control studies yielded no associations for the first, second, or third trimesters."

In other words, as they state in their conclusion, no statistically significant risk from caffeine consumption emerged from the data:

"In this meta-analysis, we observed no important association between caffeine intake during pregnancy and the risk of preterm birth for cohort and case-control studies."