Trends in mode of delivery during 1984–2003: can they be explained by pregnancy and delivery complications?
Article first published online: 15 MAY 2007
RCOG 2007 BJOG An International Journal of Obstetrics and Gynaecology
BJOG: An International Journal of Obstetrics & Gynaecology
Volume 114, Issue 7, pages 855–864, July 2007
How to Cite
O’Leary, C., De Klerk, N., Keogh, J., Pennell, C., De Groot, J., York, L., Mulroy, S. and Stanley, F. (2007), Trends in mode of delivery during 1984–2003: can they be explained by pregnancy and delivery complications?. BJOG: An International Journal of Obstetrics & Gynaecology, 114: 855–864. doi: 10.1111/j.1471-0528.2007.01307.x
- Issue published online: 15 MAY 2007
- Article first published online: 15 MAY 2007
- Accepted 21 January 2007. Published OnlineEarly 15 May 2007.
- Elective caesarean section;
- emergency caesarean section;
- spontaneous vaginal delivery;
Objectives To describe trends in mode of delivery, to identify significant factors which affected mode of delivery, and to describe how these factors and their impact have changed over time.
Design Total population birth cohort.
Setting Western Australia 1984–2003.
Participants The analysis was restricted to all singleton infants delivered at 37–42 weeks of gestation with a cephalic presentation (n= 432 327).
Methods Logistic regression analyses were undertaken to estimate significant independent risk factors separately for elective and emergency caesarean sections compared with vaginal delivery (spontaneous and instrumental), adjusting for potential confounding variables.
Main outcome measures Trends in mode of delivery, demographic factors, and pregnancy and delivery complications. Estimated likelihood of elective caesarean section compared with vaginal delivery and emergency caesarean section compared with vaginal delivery.
Results Between 1984–88 and 1999–2003, the likelihood of women having an elective caesarean section increased by a factor of 2.35 times (95% CI 2.28–2.42) and the likelihood of an emergency caesarean section increased 1.89 times (95% CI 1.83–1.96). These caesarean section rate increases remained even after adjustment for their strong associations with many sociodemographic factors, obstetric risk factors, and obstetric complications. Rates of caesarean section were higher in older mothers, especially those older than 40 years of age (elective caesarean section, OR 5.42 [95% CI 4.88–6.01]; emergency caesarean section, OR 2.67 [95% CI 2.39–2.97]), and in nulliparous women (elective caesarean section, OR 1.54 [95% CI 1.47–1.61]; emergency caesarean section, OR 3.61 [95% CI 3.47–3.76]).
Conclusions Our data show significant changes in mode of delivery in Western Australia from 1984–2003, with an increasing trend in both elective and emergency caesarean section rates that do not appear to be explained by increased risk or indication.