title: Timing of delivery and pregnancy outcomes among laboring nulliparous women.
abstract: OBJECTIVE
  The objective of the study was to compare pregnancy outcomes by completed week of gestation after 39 weeks with outcomes at 39 weeks.
  
  
  METHODS
  Secondary analysis of a multicenter trial of fetal pulse oximetry in spontaneously laboring or induced nulliparous women at a gestation of 36 weeks or longer. Maternal outcomes included a composite (treated uterine atony, blood transfusion, and peripartum infections) and cesarean delivery. Neonatal outcomes included a composite of death, neonatal respiratory and other morbidities, and neonatal intensive care unit admission.
  
  
  RESULTS
  Among the 4086 women studied, the risks of the composite maternal outcome (P value for trend < .001), cesarean delivery (P < .001), and composite neonatal outcome (P = .047) increased with increasing gestational age from 39 to 41 or more completed weeks. Adjusted odds ratios (95% confidence interval) for 40 and 41 or more weeks, respectively, compared with 39 weeks were 1.29 (1.03-1.64) and 2.05 (1.60-2.64) for composite maternal outcome, 1.28 (1.05-1.57) and 1.75 (1.41-2.16) for cesarean delivery, and 1.25 (0.86-1.83) and 1.37 (0.90-2.09) for composite neonatal outcome.
  
  
  CONCLUSIONS
  Risks of maternal morbidity and cesarean delivery but not neonatal morbidity increased significantly beyond 39 weeks.
authors.affiliation: Department of Obstetrics at University of Alabama School of Medicine at Birmingham, Birmingham, AL, USA.
authors.forename: Alan Thevenet N
authors.initials: AT
authors.lastname: Tita
authors.forename: Yinglei
authors.initials: Y
authors.lastname: Lai
authors.forename: Steven L
authors.initials: SL
authors.lastname: Bloom
authors.forename: Catherine Y
authors.initials: CY
authors.lastname: Spong
authors.forename: Michael W
authors.initials: MW
authors.lastname: Varner
authors.forename: Susan M
authors.initials: SM
authors.lastname: Ramin
authors.forename: Steve N
authors.initials: SN
authors.lastname: Caritis
authors.forename: William A
authors.initials: WA
authors.lastname: Grobman
authors.forename: Yoram
authors.initials: Y
authors.lastname: Sorokin
authors.forename: Anthony
authors.initials: A
authors.lastname: Sciscione
authors.forename: Marshall W
authors.initials: MW
authors.lastname: Carpenter
authors.forename: Brian M
authors.initials: BM
authors.lastname: Mercer
authors.forename: John M
authors.initials: JM
authors.lastname: Thorp
authors.forename: Fergal D
authors.initials: FD
authors.lastname: Malone
authors.forename: Margaret
authors.initials: M
authors.lastname: Harper
authors.forename: Jay D
authors.initials: JD
authors.lastname: Iams
mesh_terms: D000293:Adolescent; D000328:Adult; D036861:Delivery, Obstetric; D005260:Female; D006801:Humans; D007226:Infant Mortality; D007231:Infant, Newborn; D008297:Male; D015337:Multicenter Studies as Topic; D010092:Oximetry; D010298:Parity; D011247:Pregnancy; D011256:Pregnancy Outcome; D012306:Risk; D013997:Time Factors; D055815:Young Adult