title: Maternal Caffeine Consumption during Pregnancy and Risk of Low Birth Weight: A Dose-Response Meta-Analysis of Observational Studies.
abstract: Epidemiologic studies have shown inconsistent conclusions about the effect of caffeine intake during pregnancy on the risk of low birth weight (LBW). We performed a meta-analysis and linear-dose response analysis examining the association between caffeine consumption during pregnancy and risk of LBW. PubMed and EMBASE were searched for relevant articles published up to March 2014. Eight cohort and four case-control studies met all inclusion criteria. Using a random-effects model of the twelve studies, the pooled odds ratio (OR) for the risk of LBW comparing the highest versus lowest level of caffeine intake during pregnancy was 1.38 (95% CI: 1.10, 1.73). Linear dose-response analysis showed that every additional 100 mg of caffeine intake (1 cup of coffee or 2 cups of tea) per day during pregnancy was associated with a 3.0% increase in OR for LBW. There was a moderate level of overall heterogeneity with an I-squared value of 55% (95% CI: 13, 76%), and no evidence of publication bias based on Egger's test (P = 0.20) and the funnel plot. Thus, high caffeine intake during pregnancy is associated with a significant increase in the risk of LBW, and this risk appears to increase linearly as caffeine intake increases.
authors.affiliation: Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America.
authors.forename: Jongeun
authors.initials: J
authors.lastname: Rhee
authors.affiliation: Department of Social and Behavioral Sciences, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America.
authors.forename: Rockli
authors.initials: R
authors.lastname: Kim
authors.affiliation: Department of Social and Behavioral Sciences, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America.
authors.forename: Yongjoo
authors.initials: Y
authors.lastname: Kim
authors.affiliation: Department of Global Health and Population, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America.
authors.forename: Melanie
authors.initials: M
authors.lastname: Tam
authors.affiliation: Department of Health Policy and Management, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America.
authors.forename: Yizhen
authors.initials: Y
authors.lastname: Lai
authors.affiliation: Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America; Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America.
authors.forename: NaNa
authors.initials: N
authors.lastname: Keum
authors.affiliation: Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America.
authors.forename: Catherine Elizabeth
authors.initials: CE
authors.lastname: Oldenburg
mesh_terms: D001724:Birth Weight / Q000187:drug effects*; D002110:Caffeine / Q000008:administration & dosage*; D003069:Coffee / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D011247:Pregnancy
chemical_list: D003069:Coffee; D002110:Caffeine