title: Age greater than thirty-four years is an independent pregnancy risk factor in nulliparous women.
abstract: OBJECTIVE
  To compare quantitative pregnancy risk of nulliparous women 35 years and older with nulliparous women 25 to 29 years old.
  
  
  METHODS
  Maternal records for first births at three suburban hospitals from July 1, 1986, to June 30, 1990, were studied, risk-assessed retrospectively according to a group-specific risk-scoring system, and compared statistically according to age and quantitative pregnancy risk.
  
  
  RESULTS
  The older women were more likely to be high risk (score > or = 10) prepregnancy (odds ratio [OR] 2.9, 95% confidence interval [CI] 1.9 to 4.5), antepartum (OR 1.6, 95% CI 1.3 to 2.0), intrapartum (OR 2.2, 95% CI 1.8 to 2.6), and cumulatively (OR 2.6, 95% CI 2.2 to 3.2) when compared with younger women. They were also more likely to be very high risk (score > or = 20) antepartum (OR 1.8, 95% CI 1.1 to 2.9), intrapartum (OR 2.1, 95% CI 1.5 to 2.8), and cumulatively (OR 2.5, 95% CI 2.0 to 3.2). Risk increased progressively through pregnancy, revealing the intrapartum period as the time interval of maximum risk. Based on cumulative risk scoring, 64.9% of the older women were at least high risk, compared with 41.3% of the younger women (OR 2.6, 95% CI 2.2 to 3.2).
  
  
  CONCLUSIONS
  Nulliparous women 35 years and older from a predominantly middle-class, white population had a significantly higher quantifiable pregnancy risk than a similar group of women age 25 to 29, suggesting that age greater than 34 years is an independent pregnancy risk factor.
authors.affiliation: Department of Obstetrics and Gynecology, St. John Hospital and Medical Center, Detroit, MI, USA.
authors.forename: M
authors.initials: M
authors.lastname: Prysak
authors.forename: A
authors.initials: A
authors.lastname: Kisly
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007226:Infant Mortality; D007231:Infant, Newborn; D008423:Maternal Age; D007744:Obstetric Labor Complications; D016017:Odds Ratio; D010298:Parity; D011247:Pregnancy; D011248:Pregnancy Complications; D018566:Pregnancy, High-Risk; D012189:Retrospective Studies; D012307:Risk Factors