Objective: To study the association between the duration of oxytocin augmentation intervals and the risk of postpartum haemorrhage (PPH) among primiparous women in spontaneous labour.
Materials and methods: Retrospective cohort including primiparous women in spontaneous labour who received oxytocin during labour (n=454). Oxytocin augmentation intervals were dichotomized in intervals<20minutes and≥20minutes. Obstetrical and neonatal issues were analyzed according to the duration oxytocin augmentation intervals. The association between oxytocin augmentation intervals and PPH was analyzed using univariate and multivariate analysis.
Results: Oxytocin augmentation intervals were shorter than 20minutes for 43.8% of the study population. The rate of PPH was higher (9.1% vs 3.5%; P=0.014), and the use of sulprostone was more frequent (6.5% vs 3.5%; P=0.013) if oxytocin augmentation intervals were shorter than 20minutes in comparison with intervals≥20minutes. The association between oxytocin augmentation intervals and PPH remains significant after adjustment on other PPH risk factors (adjusted OR=3.48, 95% CI [1.45-8.34]). The rate of adverse neonatal issue, defined by arterial pH at birth≤7.10 and/or 5minutes score d'Apgar≤7, was higher if oxytocin augmentation intervals were<20minutes (12.1% vs 4.3%; P=0.002).
Conclusion: Our study demonstrated an increased risk of PPH for primiparous women in spontaneous labour who received oxytocin with augmentation intervals shorter than 20minutes.
Keywords: Augmentation intervals; Hémorragie du post-partum; Intervalles d’augmentation; Oxytocin; Oxytocine; Postpartum haemorrhage.
Copyright © 2016. Published by Elsevier Masson SAS.