Delivery outcomes for nulliparous women at the extremes of maternal age – a cohort study
Article first published online: 12 JUN 2013
© 2013 RCOG
BJOG: An International Journal of Obstetrics & Gynaecology
Volume 121, Issue 3, pages 261–268, February 2014
How to Cite
Delivery outcomes for nulliparous women at the extremes of maternal age – a cohort study. BJOG 2014;121:261–268., , .
- Issue published online: 16 JAN 2014
- Article first published online: 12 JUN 2013
- Manuscript Accepted: 25 APR 2013
- Age extremes;
- caesarean section;
- cohort study;
- delivery outcomes;
- maternal age
To examine the associations between extremes of maternal age (≤17 years or ≥40 years) and delivery outcomes.
Retrospective cohort study.
Urban maternity hospital in Ireland.
A total of 36 916 nulliparous women with singleton pregnancies who delivered between 2000 and 2011.
The study population was subdivided into five maternal age groups based on age at first booking visit: ≤17 years, 18–19 years, 20–34 years, 35–39 years and women aged ≥40 years. Logistic regression analyses were performed to examine the associations between extremes of maternal age and delivery outcomes, adjusting for potential confounding factors.
Main outcome measures
Preterm birth, admission to the neonatal unit, congenital anomaly, caesarean section.
Compared with maternal age 20–34 years, age ≤17 years was a risk factor for preterm birth (adjusted odds ratio [adjOR] 1.83, 95% confidence interval [95% CI] 1.33–2.52). Babies born to mothers ≥40 years were more likely to require admission to the neonatal unit (adjOR 1.35, 95% CI 1.06–1.72) and to have a congenital anomaly (adjOR 1.71, 95% CI 1.07–2.76). The overall caesarean section rate in nulliparous women was 23.9% with marked differences at the extremes of maternal age; 10.7% at age ≤17 years (adjOR 0.46, 95% CI 0.34–0.62) and 54.4% at age ≥40 years (adjOR 3.24, 95% CI 2.67–3.94).
Extremes of maternal age need to be recognised as risk factors for adverse delivery outcomes. Low caesarean section rates in younger women suggest that a reduction in overall caesarean section rates may be possible.