vasa previa
Pronunciation: VAH-sa PREE-vee-a
Condition where fetal blood vessels cross the internal cervical os, presenting ahead of the fetal presenting part.
Full Definition
A rare but serious obstetric condition occurring in approximately 1 in 2,500 pregnancies, where fetal vessels from a velamentous cord insertion or accessory placental lobe cross the internal cervical os. These unprotected vessels lie in the membranes ahead of the presenting fetal part. Rupture of membranes can cause vessel laceration and rapid fetal exsanguination. The condition requires prenatal diagnosis via transvaginal ultrasound with color Doppler and mandates delivery by cesarean section before labor onset or membrane rupture.
Usage
Usage note: Both 'previa' and 'praevia' spellings are acceptable; previa is more common in American usage.
In Context
- "Transvaginal ultrasound confirmed vasa previa, necessitating scheduled cesarean delivery at 35 weeks." — High-risk obstetric consultation
- "The patient was admitted for monitoring due to vasa previa with plans for steroid administration and delivery." — Antepartum admission note