Use of ICD-10 codes to monitor uterine rupture: Validation of a national birth registry

Objectives Uterine rupture is a rare but severe complication in pregnancies after a previous cesarean section. In Denmark, the monitoring of uterine rupture is based on reporting of relevant diagnostic codes to the Danish Medical Birth Registry (MBR). The aim of our study was to examine the validity of registration of uterine rupture in the MBR within the population of pregnant women with prior cesarean section by conducting a review of the medical records. Study design We reviewed 1709 medical records within the population of singleton pregnant woman delivering at term between 1997 and 2007. We retrieved the medical records of all women in the MBR with a code for uterine rupture during labor regardless of whether or not a prior cesarean section had been reported to the registry. In addition medical records of all women with a code for previous cesarean section and delivery of a child with adverse perinatal outcome were retrieved. Results Among women recorded in the MBR with a previous cesarean section and uterine rupture, only 60.4% actually had a uterine rupture (partial or complete). At least 16.2% of complete uterine ruptures were not reported to the registry. Considering only complete uterine ruptures, the sensitivity and specificity of the codes for uterine rupture were 83.8% and 99.1%, respectively. Conclusion During the study period the monitoring of uterine rupture in the MBR was inadequate.