Onset of labour

Labour can occur spontaneously or may be induced by medical or surgical intervention. If there is no labour, a caesarean section is performed.

The figure shows a bar chart of the proportion of women who had spontaneous labour, induced labour or no labour by a range of topics for 2019 and a line graph of topic trends from 2009 to 2019. In 2019, 126,991 women, or 42%, had spontaneous labour.

In 2019, about 2 in 5 (42.5%) mothers who gave birth had a spontaneous labour, around 1 in 3 (35%) had induced labour and 1 in 5 had no labour (23%).

Labour onset varied by maternal age group. Teenage mothers (aged under 20) were the most likely to have spontaneous labour (55%), and mothers aged 40 or over were the most likely to have no labour onset (43%).

Onset of labour varied considerably by the number of babies born from a single pregnancy, with women who had a multiple pregnancy being more likely to have no labour (57%) than women with a singleton pregnancy (22%).

The rate of spontaneous labour has fallen (from 56% in 2009 to 42.5% in 2019) with corresponding increases in the rates of induced labour (from 25% to 35%) and no labour (from 18% to 23%).

For related information see National Core Maternity Indicator Induction of labour

Induction type and reason

For mothers whose labour was induced, a combination of medical and/or surgical types of induction were most commonly used. Data excludes Western Australia.

In 2019, the main reasons for inducing labour were diabetes (14%), pre-labour rupture of membranes (10%) and prolonged pregnancy (8%).

Augmentation of labour

Once labour starts, it may be necessary to intervene to speed up or augment the labour. Labour was augmented for 17% of mothers in 2019 (30% of mothers with spontaneous onset of labour). The augmentation rate was higher among first-time mothers, at 42% of those with spontaneous labour onset, compared with 21% of mothers who had given birth previously. Data excludes Western Australia.