title: Reproductive history and risk of cognitive impairment in elderly women: a cross-sectional study in eastern China.
abstract: BACKGROUND
  Epidemiological studies suggest that proxies of higher lifetime estrogen exposure are associated with better cognitive function in postmenopausal women, but this has not been found consistently.
  
  
  OBJECTIVE
  To determine whether reproductive history, an important modifier of estrogen exposure across the lifetime, is associated with risk of cognitive impairment in postmenopausal women.
  
  
  METHODS
  We analyzed the baseline data from Zhejiang Major Public Health Surveillance Program (ZPHS) including 4,796 postmenopausal women. Cognitive impairment was assessed through the application of Mini-Mental State Examination questionnaire. Logistic regression models, controlled for an extensive range of potential confounders, were generated to examine the associations between women's reproductive history and risk of cognitive impairment in their later life.
  
  
  RESULTS
  The length of reproductive period was inversely associated with risk of cognitive impairment (p = 0.001). Odds ratio (OR) of cognitive impairment were 1.316 (95% CI 1.095∼1.582) for women with 5 or more times of full-term pregnancies, compared with those with 1∼4 times of full-term pregnancies. Women without incomplete pregnancy had a significant higher risk of cognitive impairment (OR = 1.194, 95% CI 1.000∼1.429), compared with the reference (1∼2 times of incomplete pregnancies). Oral contraceptive use (OR = 0.489, 95% CI 0.263∼0.910) and intrauterine device (IUD) use (OR = 0.684, 95% CI 0.575∼0.815) were associated with significantly reduced risk of cognitive impairment.
  
  
  CONCLUSIONS
  Our results indicated that shorter reproductive period, higher number of full-term pregnancies and no incomplete pregnancy history were associated with an increased risk of cognitive impairment. In contrast, oral contraceptive and IUD use corresponded to reduced risk of cognitive impairment.
authors.affiliation: Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, Zhejiang, China.
authors.forename: Fu-Dong
authors.initials: FD
authors.lastname: Li
authors.affiliation: Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, Zhejiang, China.
authors.forename: Fan
authors.initials: F
authors.lastname: He
authors.affiliation: Cangnan Center for Disease Prevention and Control, Wenzhou, Zhejiang, China.
authors.forename: Ting-Rui
authors.initials: TR
authors.lastname: Chen
authors.affiliation: Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, Zhejiang, China.|Kunming Medical University, Kunming, Yunnan, China.
authors.forename: Yuan-Yuan
authors.initials: YY
authors.lastname: Xiao
authors.affiliation: Cangnan Center for Disease Prevention and Control, Wenzhou, Zhejiang, China.
authors.forename: Shang-Tong
authors.initials: ST
authors.lastname: Lin
authors.affiliation: Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, Zhejiang, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Shen
authors.affiliation: Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, Zhejiang, China.
authors.forename: Xin-Yi
authors.initials: XY
authors.lastname: Wang
authors.affiliation: Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, Zhejiang, China.
authors.forename: Yu-Jia
authors.initials: YJ
authors.lastname: Zhai
authors.affiliation: Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, Zhejiang, China.
authors.forename: Xiao-Peng
authors.initials: XP
authors.lastname: Shang
authors.affiliation: Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, Zhejiang, China.
authors.forename: Jun-Fen
authors.initials: JF
authors.lastname: Lin
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002681:China; D003071:Cognition; D003072:Cognition Disorders / Q000175:diagnosis*; D003276:Contraceptives, Oral; D003430:Cross-Sectional Studies; D004967:Estrogens / Q000097:blood*; D005260:Female; D006801:Humans; D007434:Intrauterine Devices; D016015:Logistic Models; D008875:Middle Aged; D009483:Neuropsychological Tests; D016017:Odds Ratio; D017698:Postmenopause / Q000523:psychology*; D011569:Psychiatric Status Rating Scales; D017584:Reproductive History
chemical_list: D003276:Contraceptives, Oral; D004967:Estrogens
keywords: Cognitive impairment; estrogen; intrauterine device; pregnancies; reproductive history