From the Research
Introduction to Vasa Previa
Vasa previa is a condition where unprotected fetal vessels run through the membranes over the cervix, posing a significant risk to the fetus due to the potential for fetal exsanguination when the membranes rupture 1.
Signs and Symptoms
The signs and symptoms of vasa previa can be subtle and may not always be apparent until the condition is severe. However, risk factors for vasa previa include second-trimester placenta previa and low-lying placentas, velamentous cord insertion, placentas with accessory lobes, in vitro fertilization, and multifetal gestations 1.
Diagnosis
Diagnosis of vasa previa is typically made using ultrasonography, including transvaginal ultrasound and color Doppler imaging 2, 3. Early prenatal diagnosis is crucial for improving outcomes, as it allows for cesarean delivery before labor or rupture of the membranes.
Treatment Options
Treatment options for vasa previa typically involve hospitalization or management as outpatients, with careful monitoring of the fetus and preparation for cesarean delivery in a tertiary center with experienced clinicians 2, 4.
Management Strategies
Management strategies for vasa previa depend on each institutional policy, but may include:
- Elective cesarean section prior to the onset of labor
- Administration of corticosteroids to promote fetal lung maturation
- Hospitalization at about 30 to 32 weeks
- Continuous electronic fetal heart rate monitoring and rapid biochemical test for fetal hemoglobin in cases of bleeding or premature rupture of membranes
- Transfer to a tertiary facility for delivery, where a pediatrician and blood for neonatal transfusion are immediately available
Dosing Information
Corticosteroids may be administered at 28 to 32 weeks to promote fetal lung maturation, although the specific dosing regimen is not specified in the available evidence.
Differential Diagnosis and Caveats
It is essential to consider the potential for vasa previa in high-risk pregnancies, including those with low or velamentous insertion of the cord, bilobate or succenturiate placenta, or vaginal bleeding 5.
Conclusion
Vasa previa is a life-threatening condition for the fetus, but early prenatal diagnosis and management can significantly improve outcomes. Healthcare providers should be aware of the risk factors and signs of vasa previa and take a proactive approach to diagnosis and management, including careful monitoring and preparation for cesarean delivery.