Trends and morbidity associated with oxytocin use in labour in nulliparas at term

Aim: To determine the trends in oxytocin use at a population level within New South Wales and to assess the maternal and neonatal morbidities associated with the use of oxytocin. Methods: Trends in oxytocin use were assessed for women in NSW who were nulliparas at term with a singleton, cephalic fetus between 1998 and 2008. Maternal and neonatal morbidities were assessed in 2007- 2008 using linked hospital and birth data with regression analysis. Oxytocin was also assessed by indication for use being either induction or augmentation of labour. Results: The overall use of oxytocin increased from 10 291 (36.5%) of births in 1998 to 14 440 (45.4%) of births in 2008 (P < 0.0001) with the increase entirely because of the increased use for induction of labour. The use of oxytocin was associated with an increase in regional analgesia (65 to 22%), instrumental delivery (21 to 18%) and caesarean section (29 to 14%) as compared to women who did not receive oxytocin in labour. Oxytocin was also associated with an increase in severe maternal adjusted odds ratios ((aOR) 1.48, 95% CI 1.30- 1.68) and neonatal morbidity (aOR 1.29, 95% CI 1.17- 1.41). This increase in morbidity was maintained when both augmentation and induction were assessed separately. Conclusion: Oxytocin has an important role in the management of labour. However, its use should be carefully monitored with standardised treatment regimes to minimise maternal and neonatal morbidity.