Two Forms of Vasa Previa• Velamentous insertion of the umbilical cord• Normal cord insertion with vessels running between placental lobes in a bi-lobed or succenturiate (accessory) lobed placenta
Velamentous Cord InsertionVelamentousinsertion means thatthe fetal vessels,unprotected byWharton’s jelly,traverse themembranes beforethey come togetherinto the umbilicalcord.
Bilobed PlacentaA bilobed placentaconsists of two partsof the placenta.Vasa previa mayresult from vesselsrunning in themembranesbetween the twolobes.
Succenturiate Lobed PlacentaA succenturiate(accessory)lobe is a secondor thirdplacental lobethat is muchsmaller than thelargest lobe.
Risk FactorsThe International Vasa Previa Foundation (IVPF)believes that women with the followingconditions are at risk and should be investigatedwith transvaginal color Doppler ultrasound: • Low lying placenta or placenta previa • Velamentous cord insertion • Bilobed or succenturiate lobed placenta • Multiple pregnancies • In vitro fertilization (IVF) pregnancies • History of uterine surgery or D & C • Painless bleeding
Routine Ultrasound• The IVPF believes that any woman with the previous conditions should be thoroughly scanned with transvaginal color Doppler ultrasound for the presence of aberrant vessels near the internal os.• The IVPF also supports making color Doppler scanning of the placental end of the cord a standard part of the protocol during all routine obstetrical ultrasounds.
Management of Diagnosed Vasa Previa• Bedrest• Hospital admission in the third trimester• Steroid injections to promote fetal lung maturation• Elective Cesarean section at 35 weeks
How to Diagnose Vasa Previa Vasa previa can be diagnosed by using transvaginal color Doppler ultrasound.
What to Do When Vasa Previa Is Suspected after a Bleed• Emergency C-section• Aggressive resuscitation of the baby with blood transfusion following delivery• Ogita blood testing to determine origin of blood loss (maternal or fetal) for abnormally heavy bloody shows or bleeds that are not considered life threatening when the fetus is not in distress
International Vasa Previa Foundation• The International Vasa Previa Foundation agrees that vasa previa can, but should not, be a devastating complication of pregnancy.• The goals of the IVPF are to raise awareness about vasa previa and seek to adjust the medical rules and protocols worldwide such that fatal outcomes associated with vasa previa can be prevented.