Duration of third stage labour and postpartum blood loss: a secondary analysis of the WHO CHAMPION trial data

BACKGROUND: Obstetric haemorrhage continues to be a leading cause of maternal mortality, contributing to more than a quarter of the 2,443,000 maternal deaths reported between 2003 and 2009. During this period, about 70% of the haemorrhagic deaths occurred postpartum. In addition to other identifiable risk factors for greater postpartum blood loss, the duration of the third stage of labour (TSL) seems to be important, as literature shows that a longer TSL can be associated with more blood loss. To better describe the association between the duration of TSL and postpartum blood loss in women receiving active management of third stage of labour (AMTSL), this secondary analysis of the WHO CHAMPION trial data has been conducted. METHODS: This was a secondary analysis of the WHO CHAMPION trial conducted in twenty-three sites in ten countries. We studied the association between the TSL duration and blood loss in the sub cohort of women from the CHAMPION trial (all of whom received AMTSL), with TSL upto 60 min and no interventions for postpartum haemorrhage. We used a general linear model to fit blood loss as a function of TSL duration on the log scale, arm and center, using a normal distribution and the log link function. We showed this association separately for oxytocin and for Heat stable (HS) carbetocin. RESULTS: For the 10,040 women analysed, blood loss rose steeply with third stage duration in the first 10 min, but more slowly after 10 min. This trend was observed for both Oxytocin and HS carbetocin and the difference in the trends for both drugs was not statistically significant (p-value = 0.2070). CONCLUSIONS: There was a positive association between postpartum blood loss and TSL duration with either uterotonic. Blood loss rose steeply with TSL duration until 10 min, and more slowly after 10 min. Study registration The main trial was registered with Australian New Zealand Clinical Trials Registry ACTRN12614000870651 and Clinical Trial Registry of India CTRI/2016/05/006969