Surveillance of Vasa Praevia

Summary

Vasa Praevia describes the fetal vessels coursing through the fetal membranes (amnion and chorion) over the internal cervical os and below the fetal presenting part, unprotected by placental tissue or the umbilical cord. Vasa praevia carries no major maternal risk, but is associated with significant risk to the fetus. When the fetal membranes rupture, the unprotected fetal vessels are at risk of disruption with consequent fetal haemorrhage. Currently routine screening for vasa praevia is not advised by the RCOG and is not supported by the National Screening Committee. This is because there is insufficient information on the natural history of the condition and uncertainty about the best test to diagnose vasa praevia. Additionally there is no agreed management pathway for women with confirmed vasa praevia and for women with some risk factors in the absence of vasa praevia. This study will use the UK Obstetric Surveillance System (UKOSS) to investigate the incidence and risk factors of vasa praevia in the UK over one year and examine the clinical management of the condition as well as maternal and neonatal outcomes.