title: [Epidemiological features and risk factors of spontaneous abortion among rural Tibetan women at childbearing age].
abstract: OBJECTIVE
  To study the current status and risk factors of spontaneous abortion of women with Tibetan ethnicity at reproductive age in rural areas.
  
  
  METHODS
  Pregnant women who lived in Tibet were interviewed on their former reproductive history and being followed on the outcomes of pregnant from 2006 to 2012. Generalized Poisson regression model was used to explore the influencing factors of spontaneous abortion. OR value of the research factors was estimated and its 95% confidence interval counted.
  
  
  RESULTS
  There were 1 557 pregnant women under this study, with a total number of 2 687 pregnancies and 2 382 productions. 171 women underwent spontaneous abortion, with a total number of 204 times, 93 women had histories of abortion, with a total number of 101 times. Among all the Tibetan pregnant women, the ratio between spontaneous abortion and pregnant women was 7.6% while the rate of spontaneous abortion was 7.9% . Ratio between the number of women who had experienced spontaneous abortion and the total number of women under survey was 11.0% . Pregnancy appeared the important reason on spontaneous abortion. The risk of having spontaneous abortion would increase among women who had more than 3 pregnancies. Results from Poisson regression analysis revealed that the odds ratio (OR) value before the adjustment was 3.921 (95% CI:2.553-6.021) but after the adjustment, it increased to 4.722 (95% CI:2.834-7.866). The increase of production time could reduce the risk of spontaneous abortion in women of childbearing age. Risks related to spontaneous abortion were associated with the number of pregnancies. Women seemed to have lower risk for spontaneous abortion after 2009, with OR value as 0.419 (95%CI:0.285-0.616) before, compared to aOR value as 0.580 (95%CI:0.380-0.885) after the adjustment Social-demographic characteristics was not found to be particularly associated with the occurrence of spontaneous abortion.
  
  
  CONCLUSIONS
  Rate of spontaneous abortion among Tibetan women at childbearing age was not particularly high when comparing to those women living in the plain area such as Shanxi. However, in order to further reduce the incidence of spontaneous abortion among Tibetan women, approaches should include the following items:strengthening maternal health care, extending the spacing of pregnancy and reducing the frequency of pregnancy.
authors.affiliation: Faculty of Public Health, School of Medicine, Xi'an Jiaotong University, Xi'an 710061, China.
authors.forename: Xiaojing
authors.initials: X
authors.lastname: Fan
authors.affiliation: Faculty of Public Health, School of Medicine, Xi'an Jiaotong University, Xi'an 710061, China.
authors.forename: Weihua
authors.initials: W
authors.lastname: Wang
authors.affiliation: Xi'an Center of Disease Control and Prevention.
authors.forename: Ruru
authors.initials: R
authors.lastname: Liu
authors.affiliation: Faculty of Public Health, School of Medicine, Xi'an Jiaotong University, Xi'an 710061, China.
authors.forename: Shaonong
authors.initials: S
authors.lastname: Dang
authors.affiliation: Faculty of Public Health, School of Medicine, Xi'an Jiaotong University, Xi'an 710061, China. Email: tjdshn@mail.xjtu.edu.cn.
authors.forename: Yijun
authors.initials: Y
authors.lastname: Kang
mesh_terms: D000022:Abortion, Spontaneous / Q000453:epidemiology*; D000293:Adolescent; D000328:Adult; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D011247:Pregnancy; D012307:Risk Factors; D012424:Rural Population; D018609:Tibet / Q000453:epidemiology; D055815:Young Adult