Population:
The study population was all births occurring at or beyond 24 weeks’
gestational age in a major inner-city hospital network in Sydney,
Australia, and has been described in a previous
publication.9 Group A consisted of births from August
1989 to December 1999, when the annual caesarean delivery rate ranged
from 18% to 20%. Group B consisted of births from January 2009 to
December 2016, when the annual caesarean delivery rate ranged from 30%
to 32%.