Early Detection of Vasa Previa in a Low-Risk Pregnancy Leading to Favourable Perinatal Outcome: A Case Report

Vasa previa is a condition with a high mortality rate where the foetal blood vessels traverse, or lie in proximity to, the internal cervical os and are typically not supported by the umbilical cord or placenta. Recognised risk factors of vasa previa include velamentous umbilical cord insertion, assisted reproductive technologies, multiple pregnancies, bilobed or succenturiate placentas, and low-lying placental insertion. Perinatal mortality rate remains high when vasa previa is not detected antenatally, although current evidence does not support universal screening for vasa previa in the general obstetric population. This report highlights the case of a primigravida lady in whom a succenturiate placenta and low-lying vessels were identified on ultrasound at 22 weeks' gestation. She underwent a planned caesarean section and achieved a favourable perinatal outcome. Although transvaginal ultrasound can detect vasa previa antenatally, the condition may be missed even under optimal imaging conditions; this case highlights the utility of transvaginal ultrasound in the perinatal diagnosis of vasa previa, which can significantly improve perinatal outcomes. Further research into universal vasa previa screening should be considered.