title: Prevalence of gestational diabetes mellitus and its risk factors in Chinese pregnant women: a prospective population-based study in Tianjin, China.
abstract: OBJECTIVE
  We compared the increases in the prevalence of gestational diabetes mellitus (GDM) based on the 1999 World Health Organization (WHO) criteria and its risk factors in Tianjin, China, over a 12-year period. We also examined the changes in the prevalence using the criteria of International Association of Diabetes and Pregnancy Study Group (IADPSG).
  
  
  METHODS
  In 2010-2012, 18589 women who registered within 12 weeks of gestation underwent a glucose challenge test (GCT) at 24-28 gestational weeks. Amongst them, 2953 women with 1-hour plasma glucose ≥ 7.8 mmol/L underwent a 75-gram 2-hour oral glucose tolerance test (OGTT) and 781 women had a positive GCT but absented from the standard OGTT. An adjusted prevalence of GDM was calculated for the whole cohort of women by including an estimate of the proportion of women with positive GCTs who did not have OGTTs but would have been expected to have GDM. Logistic regression was used to obtain odds ratios and 95% confidence intervals using the IADPSG criteria. The prevalence of GDM risk factors was compared to the 1999 survey.
  
  
  RESULTS
  The adjusted prevalence of GDM by the 1999 WHO criteria was 8.1%, a 3.5-fold increase as in 1999. Using the IADPSG criteria increased the adjusted prevalence further to 9.3%. Advanced age, higher pre-pregnancy body mass index, Han-nationality, higher systolic blood pressure (BP), a family history of diabetes, weight gain during pregnancy and habitual smoking were risk factors for GDM. Compared to the 1999 survey, the prevalence of overweight plus obesity had increased by 1.8 folds, age ≥ 30 years by 2.3 folds, systolic BP by 2.3 mmHg over the 12-year period.
  
  
  CONCLUSIONS
  Increasing prevalence of overweight/obesity and older age at pregnancy were accompanied by increasing prevalence of GDM, further increased by change in diagnostic criteria.
authors: Department of Epidemiology and Biostatistics, School of Public Health, Tianjin Medical University, Tianjin, China; Tianjin Women and Children's Health Centre, Tianjin, China.
authors: Junhong
authors: J
authors: Leng
authors: Tianjin Women and Children's Health Centre, Tianjin, China.
authors: Ping
authors: P
authors: Shao
authors: Tianjin Women and Children's Health Centre, Tianjin, China.
authors: Cuiping
authors: C
authors: Zhang
authors: Tianjin Women and Children's Health Centre, Tianjin, China.
authors: Huiguang
authors: H
authors: Tian
authors: Tianjin Women and Children's Health Centre, Tianjin, China.
authors: Fuxia
authors: F
authors: Zhang
authors: Tianjin Women and Children's Health Centre, Tianjin, China.
authors: Shuang
authors: S
authors: Zhang
authors: Tianjin Women and Children's Health Centre, Tianjin, China.
authors: Ling
authors: L
authors: Dong
authors: Tianjin Women and Children's Health Centre, Tianjin, China.
authors: Lili
authors: L
authors: Li
authors: Population Cancer Research Program and Department of Pediatrics, Dalhousie University, Halifax, Canada.
authors: Zhijie
authors: Z
authors: Yu
authors: Department of Medicine and Therapeutics, Hong Kong Institute of Diabetes and Obesity, International Diabetes Federation Centre of Education, The Chinese University of Hong Kong-Prince of Wales Hospital-International Diabetes Federation Centre of Education, Hong Kong SAR, China.
authors: Juliana C N
authors: JC
authors: Chan
authors: Chronic Disease Epidemiology Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana, United States of America.
authors: Gang
authors: G
authors: Hu
authors: Department of Epidemiology and Biostatistics, School of Public Health, Tianjin Medical University, Tianjin, China.
authors: Xilin
authors: X
authors: Yang
mesh_terms: D000328:Adult; D002681:China / Q000453:epidemiology; D016640:Diabetes, Gestational / Q000453:epidemiology* / Q000209:etiology*; D005260:Female; D005951:Glucose Tolerance Test; D006801:Humans; D011247:Pregnancy; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors; D055815:Young Adult