title: A meta-analysis provides evidence that prenatal smoking exposure decreases age at menarche.
abstract: 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%.
authors.affiliation: School of Biological Sciences, University of Hong Kong, Pokfulam Road, Pokfulam, Hong Kong SAR, PR China. Electronic address: yermach@connect.hku.hk.
authors.forename: Anna
authors.initials: A
authors.lastname: Yermachenko
authors.affiliation: School of Biological Sciences, University of Hong Kong, Pokfulam Road, Pokfulam, Hong Kong SAR, PR China; Department of Life Sciences, College of Science and General Studies, Alfaisal University, Al Maather, P.O. Box 50927, Riyadh 11533, Kingdom of Saudi Arabia. Electronic address: vdvornyk@alfaisal.edu.
authors.forename: Volodymyr
authors.initials: V
authors.lastname: Dvornyk
mesh_terms: D000367:Age Factors; D002648:Child; D005260:Female; D006801:Humans; D008572:Menarche; D016017:Odds Ratio; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D018570:Risk Assessment; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*
keywords: Age at menarche; Meta-analysis; Prenatal exposure; Tobacco smoking