title: Pregnancy outcomes according to increasing maternal age.
abstract: OBJECTIVE
  To investigate the risks of increasing maternal age on the perinatal and obstetric outcomes.
  
  
  METHODS
  Information about 29,760 singleton pregnancies delivered between 2005 and 2008 was extracted from our database. Patients were categorized into four groups according to age: 20-29 years, 30-34 years, 35-39 years, and ≥40 years. Multivariable logistic regression analysis was used to evaluate the adjusted odd ratios (AORs) of adverse pregnancy outcomes according to maternal age after adjusting for parity, body mass index, medical history and use of in vitro fertilization.
  
  
  RESULTS
  The majority of adverse perinatal outcomes were associated with a maternal age ≥35 years as follows: low birth weight (AOR 1.2 and 1.6 for women aged 35-39 years and ≥40 years, respectively); Apgar score < 7 at 1 minute (AOR: 1.7 and 1.8); and chromosomal anomaly (AOR: 2.7 and 12.3). However, women aged ≥30 years also had greater risks for adverse maternal outcomes such as: gestational diabetes (AOR: 2.0, 3.6 and 5.1 for women aged 30-34 years, 35-39 years and ≥40 years, respectively); placenta previa (AOR: 1.6, 2.1 and 3.6); and cesarean delivery (AOR: 1.5, 2.3, and 4.1), as well as adverse fetal outcomes such as: preterm delivery (AOR: 1.2, 1.4 and 1.8) and neonatal intensive care unit transfer (AOR: 1.1, 1.2, and 1.6).
  
  
  CONCLUSIONS
  Increasing maternal age is an independent and substantial risk factor for adverse perinatal and obstetric outcomes. These adverse outcomes become more common as increasing maternal age without a clear cutoff age.
authors.affiliation: Department of Obstetrics and Gynecology, College of Medicine, University of Kwandong, Cheil General Hospital and Women's Healthcare Center, Seoul, South Korea.
authors.forename: Yu-Jin
authors.initials: YJ
authors.lastname: Koo
authors.forename: Hyun-Mee
authors.initials: HM
authors.lastname: Ryu
authors.forename: Jae-Hyug
authors.initials: JH
authors.lastname: Yang
authors.forename: Ji-Hyae
authors.initials: JH
authors.lastname: Lim
authors.forename: Ji-Eun
authors.initials: JE
authors.lastname: Lee
authors.forename: Moon-Young
authors.initials: MY
authors.lastname: Kim
authors.forename: Jin-Hoon
authors.initials: JH
authors.lastname: Chung
mesh_terms: D000328:Adult; D001034:Apgar Score; D001724:Birth Weight; D002585:Cesarean Section / Q000706:statistics & numerical data; D016640:Diabetes, Gestational / Q000453:epidemiology; D005260:Female; D005322:Premature Rupture of Fetal Membranes / Q000453:epidemiology; D006801:Humans; D046110:Hypertension, Pregnancy-Induced / Q000453:epidemiology; D015931:Intensive Care, Neonatal / Q000706:statistics & numerical data; D016015:Logistic Models; D008423:Maternal Age; D015999:Multivariate Analysis; D016017:Odds Ratio; D010921:Placenta Accreta / Q000453:epidemiology; D010923:Placenta Previa / Q000453:epidemiology; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology*; D011256:Pregnancy Outcome; D047928:Premature Birth / Q000453:epidemiology; D056910:Republic of Korea / Q000453:epidemiology; D012307:Risk Factors; D055815:Young Adult