Abstract
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
The duration of the third stage of labour (TSL) seems to be an important risk factor for greater postpartum blood loss, as literature shows that a longer TSL can be associated with more blood loss. Active management of third stage of labour (AMTSL), included in the WHO guidelines for prevention of postpartum haemorrhage (PPH), is effective in reducing both the amount of postpartum blood loss and the duration of the third stage. To better describe the association between duration of TSL and postpartum blood loss in women receiving AMTSL, we conducted this secondary analysis of WHO CHAMPION trial data.
To assess the association between the duration of third stage of labour and postpartum blood loss, a subcohort of the CHAMPION modified ITT population was selected by excluding women with missing blood loss or missing TSL duration or TSL duration more than 60 min and women with interventions. Thus, the subcohort consisted of 10,040 women.
In women with vaginal birth and not receiving interventions for treating atonic PPH or other sources of bleeding, and with TSL duration up to 60 min, there was a positive association between duration of the TSL and postpartum blood loss. The blood loss rose steeply with duration in women with TSL of 10 min or less, while in women with longer TSL duration the slope was less steep.
There was no evidence of a difference between oxytocin and HS carbetocin in the pattern of association of duration of the TSL and blood loss.
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