title: Impact of female age and nulligravidity on fecundity in an older reproductive age cohort.
abstract: OBJECTIVE
  To provide female age-related estimates of fecundity and incidence of infertility by history of prior pregnancy among women 30-44 years of age.
  
  
  METHODS
  Prospective, time-to-pregnancy cohort study.
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  Women, between 30 and 44 years of age, attempting to conceive for ≤3 months, and no known history of infertility, polycystic ovarian syndrome (PCOS), or endometriosis.
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  Fecundability and incidence of infertility.
  
  
  RESULTS
  Compared to women aged 30-31 years, fecundability was reduced by 14% in women 34-35 years of age (fecundability ratio [FR] 0.86, 95% confidence interval [CI] 0.68-1.08), 19% in women 36-37 years of age (FR 0.81, 95% CI 0.60-1.08, 30% in women 38-39 years of age (FR 0.70, 95% CI 0.48-1.01), 53% in women 40-41 years of age (FR 0.47, 95% CI 0.28-0.78), and 59% in women 42-44 years of age (FR 0.39, 95% CI 0.16-0.93). Fecundability did not differ between women aged 30-31 years and 32-33 years. In general, fecundability and cumulative probability of pregnancy was lower for women who had never had a prior pregnancy.
  
  
  CONCLUSIONS
  Women experience a significant reduction in fecundity and increase in the probability of infertility in their late thirties. At any age >30 years, women who have never conceived have a lower probability of achieving a pregnancy.
  
  
  BACKGROUND
  NCT01028365.
authors.affiliation: Department of Obstetrics and Gynecology, University of North Carolina, Chapel Hill, North Carolina. Electronic address: asteiner@med.unc.edu.
authors.forename: Anne Z
authors.initials: AZ
authors.lastname: Steiner
authors.affiliation: Yale School of Public Health, New Haven, Connecticut.
authors.forename: Anne Marie Z
authors.initials: AM
authors.lastname: Jukic
mesh_terms: D000328:Adult; D000367:Age Factors; D015331:Cohort Studies; D005260:Female; D005298:Fertility / Q000502:physiology*; D020073:Gravidity / Q000502:physiology*; D006801:Humans; D007247:Infertility, Female / Q000175:diagnosis / Q000453:epidemiology; D011247:Pregnancy; D018873:Pregnancy Rate / Q000639:trends; D011446:Prospective Studies; D012098:Reproduction / Q000502:physiology*; D011795:Surveys and Questionnaires; D061685:Time-to-Pregnancy / Q000502:physiology*
keywords: Reproductive aging; fecundability; infertility