title: Labor outcome at extremely advanced maternal age.
abstract: BACKGROUND
  Women of advanced maternal age (AMA) are at increased risk for cesarean delivery compared to non-AMA women. However, it is unclear whether this association is altered by parity and the presence or absence of a trial of labor.
  
  
  OBJECTIVE
  We sought to examine modes of delivery and maternal outcomes among AMA women stratified by parity and the presence or absence of a trial of labor.
  
  
  METHODS
  This is a retrospective cohort study of all women delivering singletons births at ≥20 weeks' gestation in the state of California from 2007 through 2011. Data were extracted from maternal discharge data linked to infant birth certificate records. We compared non-AMA women (age 20-34 years, reference group) to AMA women who were classified as follows: age 35-39, 40-44, 45-49, and ≥50 years). The primary outcome was route of delivery (cesarean vs vaginal) stratified by parity and whether a trial of labor occurred (prelabor vs intrapartum cesarean delivery). The association between a trial of labor and perinatal morbidity was also studied.
  
  
  RESULTS
  There were 1,346,889 women who met inclusion criteria, which included 181 (0.01%) women who were age ≥50 years at the time of delivery. Overall, 34.7% underwent a cesarean delivery and this risk differed significantly by age group (30.5%, 20-34 years; 40.5%, 35-39 years; 47.3%, 40-44 years; 55.6%, 45-49 years; 62.4%, >50 years). Nulliparous women age ≥50 years were significantly less likely to undergo a trial of labor compared to the reference group (relative risk [RR], 0.44; 95% confidence interval [CI], 0.32-0.62). Furthermore, nulliparous women age ≥50 years were significantly more likely to experience an intrapartum cesarean delivery (RR, 2.61; 95% CI, 1.31-5.20), however the majority (74%) who underwent a trial of labor experienced a vaginal delivery. Compared to the reference group, women age ≥50 years were 5 times more likely to experience severe maternal morbidity (1.7% vs 0.3%; RR, 5.08; 95% CI, 1.65-15.61) and their infants 3 times more likely to require neonatal intensive care unit admission (14.9% vs 5.2%; RR, 3.1; 95% CI, 2.2-4.4), however these outcomes were not associated significantly with having undergone a trial of labor, a cesarean delivery following labor, or a prelabor cesarean delivery. Similar trends were observed among multiparous women.
  
  
  CONCLUSIONS
  Compared to non-AMA women, women age ≥50 years with a singleton pregnancy experience significantly higher rates of cesarean delivery. However the majority of those who undergo a trial of labor will have a vaginal delivery. Neither a trial of labor nor a prelabor cesarean delivery is significantly associated with maternal or neonatal morbidity. These data support either approach in women of extremely AMA.
authors.affiliation: Department of Obstetrics and Gynecology, Stanford University, Stanford, CA. Electronic address: sarah.osmundson@vanderbilt.edu.
authors.forename: Sarah S
authors.initials: SS
authors.lastname: Osmundson
authors.affiliation: Department of Pediatrics, Stanford University, Stanford, CA.
authors.forename: Jeffrey B
authors.initials: JB
authors.lastname: Gould
authors.affiliation: Department of Anesthesiology, Stanford University, Stanford, CA.
authors.forename: Alexander J
authors.initials: AJ
authors.lastname: Butwick
authors.affiliation: Department of Obstetrics and Gynecology, Stanford University, Stanford, CA.
authors.forename: Amanda
authors.initials: A
authors.lastname: Yeaton-Massey
authors.affiliation: Department of Obstetrics and Gynecology, Stanford University, Stanford, CA.
authors.forename: Yasser Y
authors.initials: YY
authors.lastname: El-Sayed
mesh_terms: D000328:Adult; D000367:Age Factors; D002585:Cesarean Section / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008423:Maternal Age; D008875:Middle Aged; D010298:Parity; D011247:Pregnancy; D012189:Retrospective Studies; D012307:Risk Factors; D014219:Trial of Labor
keywords: advanced maternal age; cesarean delivery; extreme advanced maternal age; trial of labor