title: Risk factors for early miscarriage among Chinese: a hospital-based case-control study.
abstract: OBJECTIVE
  To investigate the risk factors for early miscarriage among Chinese women.
  
  
  METHODS
  Hospital-based matched case-control study.
  
  
  METHODS
  Academic medical center and maternal health hospital.
  
  
  METHODS
  620 women with early miscarriage (less than 13 weeks of gestation) and 1,240 normal pregnant women.
  
  
  METHODS
  Face-to-face questionnaire.
  
  
  METHODS
  Multivariable conditional odds ratio (OR) and 95% confidence interval (CI) to measure risk factors.
  
  
  RESULTS
  After adjustment for confounding factors, the following were independently associated with increased risk: history of miscarriage, repeated induced abortion, working night shifts, and frequent staying up late. Vitamin supplementation and regular physical activity reduced the risk of miscarriage. We did not find paternal age, alcohol consumption, or smoking status to be linked with early miscarriage.
  
  
  CONCLUSIONS
  Our findings suggest that a healthy diet, regular physical activity, and planned pregnancy may be advantageous for women in pre-pregnancy or early pregnancy. Induced abortion, working night shifts, and frequent staying up late were associated with an increased risk of miscarriage. Further work in larger populations is warranted.
authors.affiliation: Zhengzhou University, Zhengzhou, Henan, People's Republic of China; Zhengzhou Maternal and Child Health Hospital, Zhengzhou, Henan, People's Republic of China.
authors.forename: Guangli
authors.initials: G
authors.lastname: Xu
authors.affiliation: Zhengzhou Maternal and Child Health Hospital, Zhengzhou, Henan, People's Republic of China.
authors.forename: Yiming
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Zhengzhou University, Zhengzhou, Henan, People's Republic of China.
authors.forename: Liming
authors.initials: L
authors.lastname: Yang
authors.affiliation: Zhengzhou University, Zhengzhou, Henan, People's Republic of China.
authors.forename: Lu
authors.initials: L
authors.lastname: Yuan
authors.affiliation: Zhengzhou University, Zhengzhou, Henan, People's Republic of China.
authors.forename: Huafeng
authors.initials: H
authors.lastname: Guo
authors.affiliation: Zhengzhou University, Zhengzhou, Henan, People's Republic of China.
authors.forename: Fuqing
authors.initials: F
authors.lastname: Zhang
authors.affiliation: 3rd Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, People's Republic of China.
authors.forename: Yichun
authors.initials: Y
authors.lastname: Guan
authors.affiliation: Zhengzhou Maternal and Child Health Hospital, Zhengzhou, Henan, People's Republic of China. Electronic address: doctortest@126.com.
authors.forename: Wu
authors.initials: W
authors.lastname: Yao
mesh_terms: D000028:Abortion, Induced / Q000009:adverse effects; D000022:Abortion, Spontaneous / Q000208:ethnology* / Q000517:prevention & control; D000046:Academic Medical Centers; D000293:Adolescent; D000328:Adult; D044466:Asian People; D016022:Case-Control Studies; D002681:China / Q000453:epidemiology; D004032:Diet / Q000208:ethnology; D005260:Female; D005865:Gestational Age; D006771:Hospitals, Maternity; D006801:Humans; D007587:Job Description; D008019:Life Style / Q000208:ethnology*; D016015:Logistic Models; D009043:Motor Activity; D015999:Multivariate Analysis; D016017:Odds Ratio; D010561:Personnel Staffing and Scheduling; D011247:Pregnancy; D012307:Risk Factors; D012890:Sleep; D011795:Surveys and Questionnaires; D013997:Time Factors; D055815:Young Adult
keywords: Case-control study; induced abortion; miscarriage; staying up late