Since studies of association between prenatal tobacco exposure and age at menarche have reported inconsistent results so far, we conducted a meta-analysis to examine this association. In total 36 relevant articles (1995-2014) were identified, 17 of which satisfied the inclusion criteria and were used in the analysis. Nearly one month decrease (-0.092 [95%CI:-0.160, -0.024] year) in age at menarche was found in women who were exposed to tobacco in utero. The meta-regression analysis showed that average year of birth in the cohorts might significantly influence association between maternal smoking and daughter's age at menarche. Based on results obtained from 5 studies where age at menarche was treated as a categorical variable, maternal smoking status during pregnancy increased a risk for daughters to have menarche earlier than at 11 years old by 15%.
Keywords: Age at menarche; Meta-analysis; Prenatal exposure; Tobacco smoking.
Copyright © 2015 Elsevier Inc. All rights reserved.