Rates and Predictors of Caesarean Section for First and Second Births: A Prospective Cohort of Australian Women.

Objective To determine rates of vaginal delivery, emergency caesarean section, and elective caesarean section for first and second births in Australia, and to identify maternal predictors of caesarean section. Methods Data were from the Australian Longitudinal Study on Women's Health. A total of 5275 women aged 18-38 years, who had given birth to their first child between 1996 and 2012 were included; 75.0% (n = 3956) had delivered a second child. Mode of delivery for first and second singleton birth(s) was obtained from longitudinal survey data. Socio-demographic, lifestyle, anthropometric and medical history variables were tested as predictors of mode of delivery for first and second births using multinomial logistic regression. Results Caesarean sections accounted for 29.1% (n = 1535) of first births, consisting of 18.2% emergency and 10.9% elective caesareans. Mode of delivery for first and second births was consistent for 85.5% of women (n = 3383) who delivered both children either vaginally or via caesarean section. Higher maternal age and body mass index, short-stature, anxiety and having private health insurance were predictive of caesarean section for first births. Vaginal birth after caesarean section was more common in women who were older, short-statured, or had been overweight or obese for both children, compared to women who had two vaginal deliveries. Conclusions for Practice Rates of caesarean section in Australia are high. Renewed efforts are needed to reduce the number of unnecessary caesarean births, with particular caution applied to first births. Interventions could focus on elective caesareans for women with private health insurance or a history of anxiety.