title: Reproductive and lifestyle factors associated with early menopause in Mexican women.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the relationship between certain reproductive and lifestyle factors and the occurrence of early natural menopause.
  
  
  METHODS
  A case/control study was conducted on a basal population of 2510 women participating in the "Mexican Institute of Social Security health workers cohort study". Cases were defined as those women for whom natural menopause presented by age 47. Information was obtained through a self-administered questionnaire.
  
  
  RESULTS
  The risk of early menopause is associated with short menstrual cycles [<26 days, OR = 3.79 (IC 95% 1.37-10.52)], a short period of oral contraceptives use [<1 year, OR = 2.63 (IC 95% 1.10-6.29)], a lower number of pregnancies [<2, OR = 1.63 (IC 95% 1.03-2.57)], low body mass index [< or =27 kg/m2, OR = 1.64 (IC 95% 1.10-2.43)], low schooling level [<6 years, OR = 3.02 (IC 95% 1.26-7.23)], smoking history [>15 cigarettes/day, OR = 2.7 (IC 95% 1.00-7.30)], and birth cohorts [> or =950, OR = 4.09 (IC 95% 2.62-6.39)].
  
  
  CONCLUSIONS
  The findings of this study suggest that both reproductive and lifestyle factors are significant elements in the occurrence of early menopause in Mexican women.
authors.affiliation: Instituto Nacional de Salud Pública, Cuernavaca, Morelos, México. portega79@yahoo.com.mx
authors.forename: Paola A
authors.initials: PA
authors.lastname: Ortega-Ceballos
authors.forename: Carlos
authors.initials: C
authors.lastname: Morán
authors.forename: Julia
authors.initials: J
authors.lastname: Blanco-Muñoz
authors.forename: Elsa
authors.initials: E
authors.lastname: Yunes-Díaz
authors.forename: Maura S
authors.initials: MS
authors.lastname: Castañeda-Iñiguez
authors.forename: Jorge
authors.initials: J
authors.lastname: Salmerón
mesh_terms: D000328:Adult; D000367:Age Factors; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008019:Life Style; D008593:Menopause; D008800:Mexico; D008875:Middle Aged; D017584:Reproductive History