title: Comparison of maternal abdominal subcutaneous fat thickness and body mass index as markers for pregnancy outcomes: A stratified cohort study.
abstract: BACKGROUND
  Obesity in pregnancy is associated with a number of adverse outcomes. The effects of central versus general obesity in pregnancy have not been well established.
  
  
  OBJECTIVE
  To compare subcutaneous fat thickness (SFT) with body mass index (BMI) as a marker for pregnancy outcomes.
  
  
  METHODS
  A stratified retrospective cohort study was performed on 1200 pregnancies, selected from a total of 4862 nulliparous, nonsmoking women between 2006 and 2010. SFT was measured on routine ultrasound at 18-22 weeks gestation. BMI and SFT measurements were compared for estimating risks for obesity-related pregnancy outcomes using logistic regression adjusted for maternal age.
  
  
  RESULTS
  The median SFT was 18.2 mm (range 6.3-50.9 mm), the median BMI was 23.8 kg/m(2) (range 15.2-52.5), and the correlation between SFT and BMI was 0.53. For every 5 mm increase in SFT and every 5 kg/m(2) increase in BMI, the odds ratios for developing gestational diabetes mellitus were 1.40 (CI 1.22-1.61, P < 0.001) and 1.16 (CI 0.95-1.40, P = 0.1), for caesarean section 1.28 (CI 1.16-1.40, P < 0.001) and 1.16 (CI 1.05-1.28, P = 0.003), large for gestational age 1.28 (CI 1.16-1.47, P = 0.001) and 1.10 (CI 0.95-1.28, P = 0.16) and cumulative adverse obesity-related pregnancy outcomes 1.16 (CI 1.10-1.28, P = 0.002) and 1.05 (CI 0.95-1.16, P = 0.45), respectively.
  
  
  CONCLUSIONS
  SFT at 18-22 weeks gestation is better than BMI as a marker for obesity-related pregnancy outcomes. As SFT is considered a surrogate measure for visceral fat, these results suggest that central obesity is a stronger risk factor than general adiposity in pregnancy.
authors.affiliation: Melbourne Medical School, The University of Melbourne, Melbourne, Victoria, Australia.
authors.forename: Ashwin
authors.initials: A
authors.lastname: Suresh
authors.forename: Anthony
authors.initials: A
authors.lastname: Liu
authors.forename: Alison
authors.initials: A
authors.lastname: Poulton
authors.forename: Ann
authors.initials: A
authors.lastname: Quinton
authors.forename: Zara
authors.initials: Z
authors.lastname: Amer
authors.forename: Max
authors.initials: M
authors.lastname: Mongelli
authors.forename: Andrew
authors.initials: A
authors.lastname: Martin
authors.forename: Ronald
authors.initials: R
authors.lastname: Benzie
authors.forename: Michael
authors.initials: M
authors.lastname: Peek
authors.forename: Ralph
authors.initials: R
authors.lastname: Nanan
mesh_terms: D000328:Adult; D015415:Biomarkers; D015992:Body Mass Index; D002585:Cesarean Section; D016001:Confidence Intervals; D016640:Diabetes, Gestational / Q000209:etiology; D005260:Female; D005320:Fetal Macrosomia / Q000209:etiology; D006801:Humans; D016015:Logistic Models; D009765:Obesity / Q000150:complications*; D016017:Odds Ratio; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D012189:Retrospective Studies; D012307:Risk Factors; D050507:Subcutaneous Fat, Abdominal / Q000000981:diagnostic imaging; D014463:Ultrasonography; D055815:Young Adult
chemical_list: D015415:Biomarkers