Regarding vasa previa, which of the following best describes Type II vasa previa?

• A Velamentous cord insertion with fetal vessels crossing the internal os
• B Marginal cord insertion with vessels near but not crossing the os
• C Circumvallate placenta with vessels at the placental margin
• D Fetal vessels running in membranes between a succenturiate lobe and the main placenta, crossing the internal os ✓

Explanation

Vasa previa Type I arises from a velamentous cord insertion where unprotected fetal vessels traverse the internal os. Type II involves fetal vessels coursing between a bilobed or succenturiate lobe and the main placental mass, crossing the internal os — the vessels are unprotected by placental tissue or Wharton's jelly. Both types carry high risk of fetal exsanguination with membrane rupture. Type II is distinguished by its association with accessory placental lobes rather than cord insertion anomaly.

Reference: Williams Obstetrics, 26th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.