title: Advanced maternal age and adverse pregnancy outcome: evidence from a large contemporary cohort.
abstract: BACKGROUND
  Recent decades have witnessed an increase in mean maternal age at childbirth in most high-resourced countries. Advanced maternal age has been associated with several adverse maternal and perinatal outcomes. Although there are many studies on this topic, data from large contemporary population-based cohorts that controls for demographic variables known to influence perinatal outcomes is limited.
  
  
  METHODS
  We performed a population-based cohort study using data on all singleton births in 2004-2008 from the North Western Perinatal Survey based at The University of Manchester, UK. We compared pregnancy outcomes in women aged 30-34, 35-39 and ≥40 years with women aged 20-29 years using log-linear binomial regression. Models were adjusted for parity, ethnicity, social deprivation score and body mass index.
  
  
  RESULTS
  The final study cohort consisted of 215,344 births; 122,307 mothers (54.19%) were aged 20-29 years, 62,371(27.63%) were aged 30-34 years, 33,966(15.05%) were aged 35-39 years and 7,066(3.13%) were aged ≥40 years. Women aged 40+ at delivery were at increased risk of stillbirth (RR = 1.83, [95% CI 1.37-2.43]), pre-term (RR = 1.25, [95% CI: 1.14-1.36]) and very pre-term birth (RR = 1.29, [95% CI:1.08-1.55]), Macrosomia (RR = 1.31, [95% CI: 1.12-1.54]), extremely large for gestational age (RR = 1.40, [95% CI: 1.25-1.58]) and Caesarean delivery (RR = 1.83, [95% CI: 1.77-1.90]).
  
  
  CONCLUSIONS
  Advanced maternal age is associated with a range of adverse pregnancy outcomes. These risks are independent of parity and remain after adjusting for the ameliorating effects of higher socioeconomic status. The data from this large contemporary cohort will be of interest to healthcare providers and women and will facilitate evidence based counselling of older expectant mothers.
authors: Department of Obstetrics and Gynaecology, The Anu Research Centre, University College Cork, Cork University Maternity Hospital, Cork, Ireland.
authors: Louise C
authors: LC
authors: Kenny
authors: Tina
authors: T
authors: Lavender
authors: Roseanne
authors: R
authors: McNamee
authors: Sinéad M
authors: SM
authors: O'Neill
authors: Tracey
authors: T
authors: Mills
authors: Ali S
authors: AS
authors: Khashan
mesh_terms: D000328:Adult; D000367:Age Factors; D001724:Birth Weight; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008423:Maternal Age; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology / Q000503:physiopathology*; D011256:Pregnancy Outcome / Q000453:epidemiology*; D050497:Stillbirth / Q000453:epidemiology; D055815:Young Adult