The potential impact of universal screening for vasa previa in the prevention of stillbirths

Objectives
To estimate the number of pregnancies complicated by vasa previa annually in nine developed countries, and the potential preventable stillbirths associated with undiagnosed cases. We also assessed the potential impact of universal screening for vasa previa on reducing stillbirth rates.

Methods
We utilized nationally-reported birth and stillbirth data from public databases in the United States, United Kingdom, Canada, Germany, Ireland, Greece, Sweden, Portugal, and Australia. Using the annual number of births and the number and rate of stillbirths in each country, and the published incidence of vasa previa and stillbirth rates associated with the condition, we estimated the expected annual number of cases of vasa previa, those that would result in a livebirth, and the potential preventable stillbirths with and without prenatal diagnosis.

Results
There were 6,099,118 total annual births with 32,550 stillbirths, corresponding to a summary stillbirth rate of 5.34 per 1,000 pregnancies. The total expected vasa previa cases was estimated to be 5,007 (95 % CI: 3,208–7,201). The estimated number of livebirths would be 4,937 (95 % CI: 3,163–7,100) and 3,610 (95 % CI: 2,313–5,192) in pregnancies with and without a prenatal diagnosis of VP. This implies that prenatal diagnosis would potentially prevent 1,327 (95 % CI: 850–1,908) stillbirths in these countries, corresponding to a potential reduction in stillbirth rate by 4.72 % (95 % CI: 3.80–5.74) if routine screening for vasa previa was performed.

Conclusions
Our study highlights the importance of universal screening for vasa previa and suggests that prenatal diagnosis of prevention could potentially reduce 4–5 % of stillbirths