Underreporting of major obstetric haemorrhage in the Netherlands

Abstract

Major obstetric haemorrhage (MOH) is the main cause of severe maternal morbidity, incidence being estimated at 4.5 per 1000 deliveries. Cases are not routinely registered in the Netherlands. The objective of this study is to quantify the degree of underreporting of MOH in a large nationwide survey of severe acute maternal morbidity in the Netherlands (LEMMoN) and to estimate the true incidence of MOH in the Netherlands. Retrospective cross-match of the LEMMoN-database with the databases of local blood transfusion laboratories in 65 of 98 hospitals in the Netherlands during a 20-month period, using the capture-recapture method was used. From 16 of 65 centres, the reported transfusion data could not be confirmed by a local obstetrician for logistical reasons. These centres were excluded leaving 49 hospitals available for final analysis. In both databases together, 1018 unique cases of MOH were identified. Underreporting to LEMMoN was 35%. Hence, the true incidence of MOH in the Netherlands is at least 6.1 instead of 4.5 per 1000 deliveries. The estimated underreporting of MOH of 35% is considerable. Underreporting is inherent to large observational multicentre studies and should be anticipated and quantified to facilitate fair comparison of epidemiologic data.

Transfusion practices in postpartum hemorrhage: a population‐based study

“…These results suggest that under‐transfusion may exist in this context. Moreover, our results suggest that women with PPH in our study may have received smaller volumes of RBCs compared with those in the LEMMoN study, a recent nationwide study of severe acute maternal morbidity performed in the Netherlands . In this study, PPH with transfusion of at least four RBC units occurred for 0.6% of deliveries, three times more frequently than in our study.…”

Incidence, management and outcome of women requiring massive transfusion after childbirth in the Netherlands: secondary analysis of a nationwide cohort study between 2004 and 2006

“…There may have been inclusion bias, since identification and management of cases may differ between obstetricians and hospitals. Underreporting is a concern, however, we have previously observed that there is a negative correlation between the rate of underreporting and the number of red blood cell concentrates transfused [34]. Therefore, we would expect a low rate of underreporting.…”

The Nordic Obstetric Surveillance Study: a study of complete uterine rupture, abnormally invasive placenta, peripartum hysterectomy, and severe blood loss at delivery

“…The study of severe blood loss at delivery is also challenged by a lack of uniform international definitions. A Scottish study reported a rate of 19/10 000 deliveries (definition: transfusion of ≥5 red blood cell units), and a Dutch study reported 61/10 000 deliveries (definition: ≥4 red blood cell units) . The difference in transfusion rates may reflect diverse risk factors, definitions, and clinical management in the populations, but they may also indicate variations in the definition of the complications.…”