[Factors associated with blood loss during precipitate labor]

Precipitate labour is related to the appearance of postpartum haemorrhage due to posterior uterine atony. However, preventive measures that may be effective in reducing blood loss in this type of delivery are still unknown. Therefore, the objective of this study was to determine the risk factors associated with blood loss produced in precipitate labour.

This was an observational, analytical retrospective cohort study based on a total sample of 742 women with vaginal delivery whose duration was less than 180 minutes, during the period 2010-2014. Dead foetus antepartum gestations, twin gestations and labour induction were excluded from the analysis. The main outcome variable was intrapartum blood loss.

By making use of multivariate analysis, the risk factors independently associated with higher blood loss (g/dL) during precipitate labour were nulliparity (0.38; p<0.001), higher antepartum haemoglobin levels (0.23; p<0.001), higher gestational age (0.06; p<0.001), manual removal of the placenta (0.92; p=0.004) and the use of episiotomy (0.34; p<0.001). Performing active management emerges as a protective factor against increased blood loss (-0.23; p<0.001). The average loss of haemoglobin was 1.0 g/dL (standard deviation =0.92).

The restriction in the practice of episiotomy and the use of active management can therefore be established as key measures that professionals can modify in order to reduce blood loss during precipitate labour and to improve these mothers' postpartum period. Key words. Haemoglobin. Precipitate labour.