VP in pregnancy refers to vasa previa, a condition where fetal umbilical vessels, unprotected by the umbilical cord or placental tissue, cross the fetal membranes in the lower uterine segment, positioned below the baby's presenting part [2–4]. This location poses a significant risk of vessel rupture and fetal hemorrhage, especially during labor and delivery.
Understanding Vasa Previa
Essentially, vasa previa means the baby's blood vessels are exposed and vulnerable, lying in front of the baby's path during birth. These vessels are only covered by the membranes, not protected by the umbilical cord or placenta.
Risks Associated with Vasa Previa
- Fetal Hemorrhage: The primary danger is that these unprotected vessels can rupture during labor, leading to rapid fetal blood loss.
- Fetal Asphyxia: Even without complete rupture, compression of the vessels can restrict blood flow to the fetus, leading to oxygen deprivation (asphyxia).
- High Fetal Mortality: If not diagnosed and managed properly, vasa previa carries a high risk of fetal death.
Diagnosis of Vasa Previa
- Antenatal Ultrasound: Vasa previa can often be detected during routine prenatal ultrasounds, especially when color Doppler imaging is used to visualize blood vessels.
- Suspicion Based on Risk Factors: Certain conditions increase the likelihood of vasa previa, such as:
- Low-lying placenta
- Multiple pregnancies
- In-vitro fertilization (IVF) pregnancies
- Velamentous cord insertion (where the umbilical cord inserts into the membranes rather than directly into the placenta)
Management of Vasa Previa
- Scheduled Cesarean Section: The standard of care for diagnosed vasa previa is a planned cesarean delivery, typically around 35-36 weeks gestation, to avoid the risks of labor and membrane rupture.
- Monitoring and Hospitalization: Depending on the gestational age at diagnosis, the mother may be monitored closely or hospitalized to ensure prompt intervention if labor begins spontaneously.
- Neonatal Resuscitation Team: Having a neonatal resuscitation team present at delivery is crucial to address any potential complications related to fetal blood loss.
Example Scenario
Imagine a woman at 32 weeks gestation with a history of a low-lying placenta on her 20-week ultrasound. A follow-up ultrasound with Doppler reveals blood vessels crossing over the internal cervical os. This finding is highly suggestive of vasa previa, and the woman would be scheduled for regular monitoring and a planned Cesarean section at approximately 35 weeks.
