title: Gestational age-specific neonatal morbidity among pregnancies complicated by advanced maternal age: a population-based retrospective cohort study.
abstract: OBJECTIVE
  Compare significant neonatal morbidity frequency differences in advanced maternal age (AMA) versus non-AMA pregnancies, assessing which gestational week is associated with the lowest morbidity risk.
  
  
  METHODS
  Population-based retrospective cohort study. Adverse neonatal outcome frequency differences were stratified by each week of gestation. Multivariate logistic regression estimated the relative risk (RR) of composite neonatal morbidity for women aged 35-39, 40-44, 45-49 and 50-55 versus 18-34 years, adjusted sequentially for relevant risk factors.
  
  
  RESULTS
  Neonatal morbidity decreased with each advancing week of term gestation, lowest at 39 weeks for all the groups. Adverse neonatal outcome risk for births to AMA women increased at 40 weeks: 35-39 years adjRR 1.12 [1.01-1.24] and ≥40 years 1.24 [1.01-1.52]. Each older maternal age category had increased risk for overall neonatal morbidity: 35-39 years adjRR 1.11 [95% CI 1.08-1.15], 40-44 years 1.21 [95% CI 1.14-1.29] and 45-49 years 1.34 [95% CI 1.05-1.69].
  
  
  CONCLUSIONS
  Lowest neonatal morbidity risk is at 39-week gestation with a significantly increased risk observed thereafter, especially in women ≥40 years.
authors.affiliation: a Department of Obstetrics and Gynecology , and.
authors.forename: Amy M
authors.initials: AM
authors.lastname: Valent
authors.affiliation: a Department of Obstetrics and Gynecology , and.
authors.forename: Tondra
authors.initials: T
authors.lastname: Newman
authors.affiliation: b Department of Environmental Health , University of Cincinnati , Cincinnati , OH , USA , and.
authors.forename: Aimin
authors.initials: A
authors.lastname: Chen
authors.affiliation: a Department of Obstetrics and Gynecology , and.
authors.forename: Amy
authors.initials: A
authors.lastname: Thompson
authors.affiliation: a Department of Obstetrics and Gynecology , and.|c Center for Prevention of Preterm Birth, Perinatal Institute, Cincinnati Children's Hospital Medical Center , Cincinnati , OH , USA.
authors.forename: Emily
authors.initials: E
authors.lastname: DeFranco
mesh_terms: D000293:Adolescent; D000328:Adult; D001034:Apgar Score; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D015931:Intensive Care, Neonatal / Q000706:statistics & numerical data; D008423:Maternal Age; D008875:Middle Aged; D011247:Pregnancy; D011256:Pregnancy Outcome; D012189:Retrospective Studies; D055815:Young Adult
keywords: Advanced maternal age; adverse neonatal outcomes; gestational week of delivery