Systematic screening for vasa previa at the 20-week anomaly scan

Area of Science:

• Maternal-Fetal Medicine
• Diagnostic Imaging
• Obstetrics

Background:

• Vasa previa poses a high risk of fetal morbidity and mortality due to potential fetal hemorrhage.
• Prenatal diagnosis of vasa previa significantly improves fetal outcomes.
• Systematic screening protocols for vasa previa are not widely implemented, and evidence from routine practice is limited.

Purpose of the Study:

• To evaluate the performance of systematic screening for vasa previa.
• To assess the feasibility of screening by examining placental cord insertion at the 20-week anomaly scan.

Main Methods:

• Retrospective analysis of 6038 pregnancies screened for vasa previa.
• Prospective screening involved assessing placental cord insertion site at the 20-week anomaly scan.
• Vaginal sonography was used for vasa previa examination in cases with marginal/velamentous cord insertion or specific placental anomalies.

Main Results:

• All 21 identified cases of vasa previa were diagnosed prenatally.
• Marginal or velamentous cord insertion was noted in 18 cases; 3 involved other placental anomalies.
• All fetuses in vasa previa cases survived, with no reported fetal or neonatal deaths or need for blood transfusions.

Conclusions:

• Systematic screening for vasa previa is feasible and efficient.
• Assessing placental cord insertion site is a key component of effective vasa previa screening.
• This screening approach can be integrated into routine practice for pregnancies without placenta previa or specific placental variations.