title: Screening high-risk clusters for developing birth defects in mothers in Shanxi Province, China: application of latent class cluster analysis.
abstract: BACKGROUND
  Few studies on cluster-based synthetic effects of multiple risk factors for birth defects have been reported. The present study aimed to identify maternal exposure clusters, explore the association between clusters of risk factors and birth defects, and further screen women with high risk for birth defects among expectant mothers.
  
  
  METHODS
  Data were drawn from a large-scale, retrospective epidemiological survey of birth defects from 2006 to 2008 in six counties of Shanxi Province, China, using a three-level stratified random cluster sampling technique. Overall risk factors were extracted using eight synthetic variables summed and examined as a total risk factor score: maternal delivery age, genetic factors, medical history, nutrition and folic acid deficiency, maternal illness in pregnancy, drug use in pregnancy, environmental risk factors in pregnancy, and unhealthy maternal lifestyle in pregnancy. Latent class cluster analysis was used to identify maternal exposure clusters based on these synthetic variables. Adjusted odds ratios (AOR) were used to explore associations between clusters and birth defects, after adjusting for confounding variables using logistic regression.
  
  
  RESULTS
  Three latent maternal exposure clusters were identified: a high-risk (6.15%), a moderate-risk (22.39%), and a low-risk (71.46%) cluster. The prevalence of birth defects was 14.08%, 0.85%, and 0.52% for the high-, middle- and low-risk clusters respectively. After adjusting for maternal demographic variables, women in the high-risk cluster were nearly 31 times (AOR: 30.61, 95% CI: [24.87, 37.67]) more likely to have an infant with birth defects than low-risk women.
  
  
  CONCLUSIONS
  A high-risk group of mothers in an area with a high risk for birth defects were screened in our study. Targeted interventions should be conducted with women of reproductive age to improve neonatal birth outcomes in areas with a high risk of birth defects.
authors.affiliation: Division of Health Statistics, School of Public Health, Shanxi Medical University, No. 56 South Xinjian Road, Taiyuan, Shanxi, 030001, PR China. 56926245@qq.com.
authors.forename: Hongyan
authors.initials: H
authors.lastname: Cao
authors.affiliation: Division of Health Statistics, School of Public Health, Shanxi Medical University, No. 56 South Xinjian Road, Taiyuan, Shanxi, 030001, PR China. 786522663@qq.com.
authors.forename: Xiaoyuan
authors.initials: X
authors.lastname: Wei
authors.affiliation: Population and Family planning Commission of Shanxi province, No. 11 North Beiyuan Road, Taiyuan, Shanxi, 030006, PR China. 13934527993@163.com.
authors.forename: Xingping
authors.initials: X
authors.lastname: Guo
authors.affiliation: Population and Family planning Commission of Shanxi province, No. 11 North Beiyuan Road, Taiyuan, Shanxi, 030006, PR China. 16398656@qq.com.
authors.forename: Chunying
authors.initials: C
authors.lastname: Song
authors.affiliation: Division of Health Statistics, School of Public Health, Shanxi Medical University, No. 56 South Xinjian Road, Taiyuan, Shanxi, 030001, PR China. lifearena@163.com.
authors.forename: Yanhong
authors.initials: Y
authors.lastname: Luo
authors.affiliation: Division of Health Statistics, School of Public Health, Shanxi Medical University, No. 56 South Xinjian Road, Taiyuan, Shanxi, 030001, PR China. cui@stt.msu.edu.|Department of Statistics and Probability, Michigan State University, East Lansing, MI, 48824, USA. cui@stt.msu.edu.
authors.forename: Yuehua
authors.initials: Y
authors.lastname: Cui
authors.affiliation: Department of Developmental Pediatrics, Affiliated Children's Hospital of Shanxi Medical University, No. 15 North Xinmin Road, Taiyuan, Shanxi, 030013, PR China. 13835151930@126.com.
authors.forename: Xianming
authors.initials: X
authors.lastname: Hu
authors.affiliation: Division of Health Statistics, School of Public Health, Shanxi Medical University, No. 56 South Xinjian Road, Taiyuan, Shanxi, 030001, PR China. sxmuzyb@126.com.
authors.forename: Yanbo
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000328:Adult; D002681:China; D016000:Cluster Analysis; D000013:Congenital Abnormalities / Q000453:epidemiology* / Q000209:etiology*; D005260:Female; D005494:Folic Acid Deficiency; D006801:Humans; D007223:Infant; D008019:Life Style; D016015:Logistic Models; D008403:Mass Screening; D008423:Maternal Age; D018811:Maternal Exposure; D016017:Odds Ratio; D011247:Pregnancy; D011248:Pregnancy Complications; D012189:Retrospective Studies; D012307:Risk Factors