title: Primary cesarean delivery among parous women in the United States, 1990-2003.
abstract: OBJECTIVE
  To explore trends in primary cesarean delivery rates among parous women with singleton pregnancies in the United States between 1990 and 2003.
  
  
  METHODS
  The analysis used data from national birth files based on U.S. birth certificates between 1990 and 2003. The primary cesarean delivery rate was defined as the number of primary cesarean deliveries per 100 deliveries among parous women with singleton pregnancies who have not had a previous cesarean delivery. A stratified analysis was employed to investigate whether trends varied by maternal age, gestational age, race/ethnicity, or region.
  
  
  RESULTS
  In the United States, the primary cesarean delivery rate among parous women decreased modestly from 7.1% in 1990 to 6.6% in 1996 but increased progressively to 9.3% in 2003. The increase in cesarean rates from 1996 to 2003 varied substantially by race/ethnicity: Hispanic and non-Hispanic white women exhibited lower and similar rates, whereas rates for non-Hispanic black women were consistently higher and rose by a far greater extent across the years. There were substantial differences in cesarean delivery trends across geographic divisions, with greatest increases observed in the mid-Atlantic, South Central, and South Atlantic areas of the United States. Primary cesarean rates also declined considerably with increasing gestational age.
  
  
  CONCLUSIONS
  Similar to the overall cesarean delivery rate, primary cesarean rates among parous women with singleton pregnancies have increased substantially in the United States since 1996.
  
  
  METHODS
  III.
authors.affiliation: From the Epidemiology and Contraception and Reproductive Health Branches, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland.
authors.forename: Jessie
authors.initials: J
authors.lastname: Ford
authors.forename: Jagteshwar
authors.initials: J
authors.lastname: Grewal
authors.forename: Rafael
authors.initials: R
authors.lastname: Mikolajczyk
authors.forename: Susan
authors.initials: S
authors.lastname: Meikle
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
mesh_terms: D000293:Adolescent; D000328:Adult; D001719:Birth Certificates; D002585:Cesarean Section / Q000706:statistics & numerical data / Q000639:trends*; D005260:Female; D006801:Humans; D010298:Parity; D011247:Pregnancy; D014481:United States / Q000453:epidemiology; D055815:Young Adult