title: Maternal pre-pregnancy overweight and obesity and the risk of cesarean delivery in nulliparous women.
abstract: OBJECTIVE
  To examine the effect of maternal pre-pregnancy overweight and obesity on the risk of term cesarean delivery in nulliparous women.
  
  
  METHODS
  The authors examined data from 641 nulliparous women with a term pregnancy that participated in the Pregnancy, Infection, and Nutrition Study from 1995 to 2002. Unadjusted and adjusted risk ratios and 95% confidence intervals (CI) were computed for normal weight (BMI 19.8-26.0 kg/m(2)), overweight (BMI 26.1-29.0 kg/m(2)), and obese (BMI>29.0 kg/m(2)) women. Normal weight women served as the referent population.
  
  
  RESULTS
  The unadjusted risk ratio for cesarean delivery for overweight women compared with normal weight women was 1.4 (95% CI, 0.97, 2.1) and for obese women compared with normal weight women was 1.4 (95% CI, 1.03, 2.0). After controlling for maternal height, education, weight gain during pregnancy, and labor induction, the adjusted risk ratio for cesarean delivery among overweight women was 1.2 (95% CI, 0.8, 1.8). The adjusted risk ratio for obese women was 1.5 (95% CI, 1.05, 2.0).
  
  
  CONCLUSIONS
  Our analysis confirms that there is a moderate association between maternal pre-pregnancy obesity and an unplanned term cesarean delivery. However, the risk is not as large as previously reported.
authors.affiliation: Department of Maternal and Child Health, School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA. amv@med.umich.edu
authors.forename: Anjel
authors.initials: A
authors.lastname: Vahratian
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Siega-Riz
authors.forename: David A
authors.initials: DA
authors.lastname: Savitz
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
mesh_terms: D000293:Adolescent; D000328:Adult; D015992:Body Mass Index; D002585:Cesarean Section / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D009765:Obesity / Q000150:complications*; D010298:Parity; D011247:Pregnancy; D011248:Pregnancy Complications; D011256:Pregnancy Outcome; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D014481:United States