Another possible explanation of the

Another possible explanation of the findings is
that staff may have underestimated major haemorrhage
in 2008 and the practice change to using
Syntocinon may have prompted greater awareness
of estimated blood loss rates. In 2008, 22/3704
(0.59%) women were reported to have had a
blood loss in excess of 1000 ml following vaginal
delivery compared to 63/3614 (1.74%) in 2010.
Nevertheless, 47 women in 2008 and 45 women
in 2010 who had a vaginal delivery required a
blood transfusion, suggesting that staff were
more likely to have underestimated blood loss in
2008. It is recognized in the literature that visual
assessment of blood loss at delivery is unreliable
and either results in significant underestimation
or overestimation (Combs et al, 1991a; 1991b).
Visual assessment of blood loss is the normal
practice at the Trust where this study was undertaken.
As previously discussed the introduction of
Syntocinon may have improved the estimation of
blood loss in this study, as shown by the increased
reported incidence of blood loss over 1000 ml
(0.59% vs. 1.74%) between the two time periods.
In accordance with the evidence, the rate of 1.74%
reflects a more accurate assessment and is more
reflective of the incidence of PPH with blood loss
greater than 1000 ml following vaginal delivery as
in the literature—Bais et al (2004) and Magann et
al (2005a) reported rates of 3% and 5% respectively
following vaginal delivery.