A potentially lethal case of Vasa Previa reported by NEJM

Dr Shinya Matsuzaki, at Osaka University, Osaka, Japan and colleagues have reported a rare and potentially lethal case of Vasa Previa that has appeared in NEJM.

Vasa Previa is a condition in which fetal blood vessels are within 2 cm of the internal cervical os or traverse it without protection from the placenta or Wharton’s jelly. These unprotected fetal blood vessels are at high risk for rupture during labour and vaginal delivery; cesarean delivery before rupture of the membranes is indicated. vasa Previa is associated with very high fetal mortality rates and is often not detected until catastrophic events occur.

There have been reports estimating the incidence of vasa previa as being about 1 of every 5000 deliveries. The mortality rate has been reported to be as high as 33% to 100%9 following spontaneous or artificial rupture of the membranes.

According to history, a 37-year-old woman presented to the obstetrical clinic for routine fetal ultrasonography at 27 weeks of gestation. Her vaginal ultrasonography was carried out which revealed a low-lying posterior placenta and velamentous cord insertion (i.e., rather than being inserted centrally on the placenta, the umbilical cord was affixed to the fetal membranes and tracked the surface of the membranes to the placenta).

Courtesy NEJM

The Transvaginal colour Doppler ultrasonography of the patient revealed fetal blood vessels covering the internal cervical os, a finding consistent with vasa previa. The patient underwent a scheduled cesarean delivery at 34 weeks of gestation.

A low, transverse uterine incision revealed an intact amniotic membrane with fetal blood vessels crossing over the membrane that covered the head of the fetus. Examination of the placenta revealed membranous vessels that merged to form the umbilical cord, confirming the presence of velamentous cord insertion. The infant had transient tachypnea of the newborn but recovered well, and both mother and baby were ultimately discharged home.