Labour onset varied by maternal age group. Teenage mothers (aged under 20) were the most likely to have spontaneous labour (52%), and mothers aged 40 or over were the most likely to have no labour onset (44%).
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 (59%) than women with a singleton pregnancy (23%).
The rate of spontaneous labour has fallen (from 56% in 2010 to 41% in 2020) with corresponding increases in the rates of induced labour (from 25% to 36%) and no labour (from 19% to 24%).
For related information see National Core Maternity Indicator Induction of labour
For more information on onset of labour see National Perinatal Data Collection annual update data table 2.26.
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 2020, the main reasons for inducing labour were diabetes (15%), pre-labour rupture of membranes (11%) and prolonged pregnancy (12%).
For more information on induction type and reason see National Perinatal Data Collection annual update data table 2.28 and 2.29.
Augmentation of labour
Once labour starts, it may be necessary to intervene to speed up or augment the labour. Labour was augmented for 16% of mothers in 2020 (29% of mothers with spontaneous onset of labour). The augmentation rate was higher among first-time mothers, at 41% of those with spontaneous labour onset, compared with 21% of mothers who had given birth previously. Data excludes Western Australia.
For more information on augmentation of labour see National Perinatal Data Collection annual update data table 2.27.
References
Coates D, Makris A, Catling C, Henry A, Scarf V, Watts N, Fox D, Thirukumar P, Wong V, Russell H and Homer C (2020) ‘A systematic scoping review of clinical indications for induction of labour’, PLOS One, 15(1):e0228196, doi:10.1371/journal.pone.0228196.
Grivell RM, Reilly AJ, Oakey H, Chan A and Dodd JM (2012) ‘Maternal and neonatal outcomes following induction of labor: a cohort study’, ACTA Obstetricia et Gynecologica Scandinavica, 91(2):198–203, doi:10.1111/j.1600-0412.2011.01298.x.