Incidence of postpartum haemorrhage defined by quantitative blood loss measurement: a national cohort

Abstract

Background: Visual estimation of blood loss following delivery often under-reports actual bleed volume. To improve accuracy, quantitative blood loss measurement was introduced for all births in the 12 hospitals providing maternity care in Wales. This intervention was incorporated into a quality improvement programme (Obstetric Bleeding Strategy for Wales, OBS Cymru). We report the incidence of postpartum haemorrhage in Wales over a 1-year period using quantitative measurement.

Methods: This prospective, consecutive cohort included all 31,341 women giving birth in Wales in 2017. Standardised training was cascaded to maternity staff in all 12 hospitals in Wales. The training comprised mock-scenarios, a video and team drills. Uptake of quantitative blood loss measurement was audited at each centre. Data on postpartum haemorrhage of > 1000 mL were collected and analysed according to mode of delivery. Data on blood loss for all maternities was from the NHS Wales Informatics Service.

Results: Biannual audit data demonstrated an increase in quantitative measurement from 52.1 to 87.8% (P < 0.001). The incidence (95% confidence intervals, CI) of postpartum haemorrhage of > 1000 mL, > 1500 mL and > 2000 mL was 8.6% (8.3 to 8.9), 3.3% (3.1 to 3.5) and 1.3% (1.2 to 1.4), respectively compared to 5%, 2% and 0.8% in the year before OBS Cymru. The incidence (95% CI) of bleeds of > 1000 mL was similar across the 12 hospitals despite widely varied size, staffing levels and case mix, median (25th to 75th centile) 8.6% (7.8-9.6). The incidence of PPH varied with mode of delivery and was mean (95% CI) 4.9% (4.6-5.2) for unassisted vaginal deliveries, 18.4 (17.1-19.8) for instrumental vaginal deliveries, 8.5 (7.7-9.4) for elective caesarean section and 19.8 (18.6-21.0) for non-elective caesarean sections.

Conclusions: Quantitative measurement of blood loss is feasible in all hospitals providing maternity care and is associated with detection of higher rates of postpartum haemorrhage. These results have implications for the definition of abnormal blood loss after childbirth and for management and research of postpartum haemorrhage.

Keywords: Epidemiology; Haemorrhage; Incidence; Measured blood loss; Postpartum.

Fig. 1

Objective measurement of all blood loss by mode of delivery. The proportion of maternities where all blood loss was objectively measured is shown for October 2016, before OBS Cymru started and subsequently in June and December 2017. The proportion of maternities where blood loss was measured was compared between October 2016 and December 2017 by the Chi Square test. Category 1 caesarean sections are where there is immediate threat to life of mother or fetus, category 2 maternal or fetal compromise that is not immediately life-threatening, category 3 is no maternal or fetal compromise but needs early delivery and category 4 is timed to suit woman and staff

Fig. 2

Incidence of blood loss more than 1000 mL at each maternity unit during 2017. Funnel plot of the number of bleeds more than 1000 mL per 1000 maternities during 2017 at each obstetric unit in Wales