Vasa previa is a condition where fetal blood vessels in the umbilical cord pass through the membranes covering the cervix instead of being contained within the umbilical cord. This puts the vessels at risk of rupture during cervical dilation of labor, which can cause life-threatening bleeding. Risk factors include low-lying placenta, multiple gestation, abnormal umbilical cord insertion, IVF pregnancy, and previous uterine surgery. Diagnosis is made using an amniotic fluid test to detect fetal hemoglobin. Treatment involves close monitoring, corticosteroids for lung maturity, and planned cesarean delivery between 35-36 weeks to avoid rupture of membranes.

1. VASA PREVIA
Dr.Regan,
MD

2. Definition
• Rupture of a fetal vessel
• Result of a velamentous insertion of the umbilical cord into the
membranes
–Veins travel across the amniotic membranes before coming
together in umbilical cord

3. Pathophysiology
• This is a situation where blood vessels (or their branches) in the
umbilical cord develop a route away from the cord and placenta
proper and are found just above the cervical opening
• That means they are, in effect, between the baby’s leading part
(usually the head) and the cervical opening
• Once the cervix starts dilating, the delicate vessels will be stretched
and will soon tear.
• This will unleash torrential vaginal bleeding.

4. Risk factors
• A low lying placenta (placenta praevia)
• Multiple pregnancy (twins or more)
• A placenta where the cord insertion is peripheral rather than central
(velamentous insertion of cord)
• IVF pregnancy: For some obscure reason, IVF pregnancy increases the
risk of vasa praevia almost 10-fold to an estimated 1 in 300.
• Previous history of uterine surgery including minor procedures such
as D&C

5. ALTERATIONS IN THE FETAL HEART RATE
• Initial fetal tachycardia—fetus attempts to compensate for acute
blood loss
• Bradycardia
• Intermittent accelerations
Note that;
• Fetal mortality reported to be greater than 50% Hence you must
make diagnosis rapidly and institute definitive therapy and delivery

6. Investigation
APT TEST
 Used to detect fetal blood.
• The blood is mixed with a small amount of tap water to cause
hemolysis.
• The sample is next centrifuged for several minutes.
• The pink hemoglobin-containing supernatant is then mixed with 1 mL
of 1% NaOH for each 5 mL of supernatant.
• The color of the fluid is assessed after 2 minutes. Fetal hemoglobin
will stay pink and adult hemoglobin will turn yellow-brown.

7. Management
• Consider hospitalization in the third trimester to provide proximity to
facilities for emergency cesarean delivery.
• Fetal surveillance to detect compression of vessels.
• Antenatal corticosteroids to promote lung maturity.
• Elective cesarean delivery at 35 to 36 weeks of gestation.
• Avoid amniotomy as the risk of fetal mortality is 60-70% with rupture
of the membranes

8. • THE END
• ANY QUESTION……..?????????