Main findings
Our main finding was that most of the steep rise in the caesarean
delivery rate, which increased from about 19% to 30% between 1989 and
2016, could be attributed to changes in maternal characteristics of the
obstetric population. Fifty-six percent of the rise was explained by
changes in maternal age, body mass index, maternal history of previous
caesarean delivery, and parity. In other words, the caesarean delivery
rate was expected to increase from 19.1% to 25.3% over the time period
studied had there been no changes in obstetric practice whatsoever. The
management of malpresentation, multiple gestation, and preterm birth
explained 10% of the rise in the caesarean delivery rate, and the
exclusion of some ‘newer’ indications for planned (pre-labour) caesarean
delivery resulted in 78% of the rise in caesarean deliveries being
explained. The impact of planned caesarean delivery by maternal choice
alone was minimal.