Abstract
Background: Postpartum haemorrhage (PPH) rates are increasing in
developed countries. A reliable prognostic tool for PPH has potential to
aid prevention efforts. Objective: To systematically identify and
appraise prognostic modelling studies for prediction of PPH. Search
strategy: MEDLINE, Embase, CINAHL and the Cochrane Library were searched
using a combination of terms and synonyms including ‘prediction tool’,
‘risk score’ and ‘postpartum haemorrhage’. Selection criteria: Any
observational or experimental study developing a prognostic model for
women’s risk of PPH. English language publications. Data collection and
analysis: Predesigned data extraction form to record: data source;
participant criteria; outcome; candidate predictors; actual predictors;
sample size; missing data; model development; model performance; model
evaluation; interpretation. Main Results: Of 1723 citations screened, 10
studies were eligible for inclusion. An additional paper was published
and identified following completion of the search. Studies addressed
populations of women who experienced; placenta praevia; vaginal births;
caesarean birth; and the general obstetric population. Primary study
authors deemed four models to be confirmatory. There was a high risk of
bias across all studies due to a combination of retrospective selection
of women, low sample size, no internal validation, suboptimal external
validation and no reporting of missing data. Conclusion: Of eleven
prognostic models for PPH risk, one developed for women undergoing
caesarean section is deemed suitable for external validation. Future
research requires robust internal and external validation of existing
tools and development of a model that can be used to predict PPH in the
general obstetric population. Protocol registration number: PROSPERO
95587