Definition: Vasa previa is when the baby's blood vessels come down in front of the baby's head or other presenting part. Typically the vessels are protected from the normal movement of the baby and compression during the contractions of labor by the Wharton's jelly. This makes a vaginal birth dangerous because of the possible disruption of the fetal blood supply due to the lack of protection and their location. It can also be seen in conjunction with a velamentous cord insertion or a multilobed placenta. Vasa previa happens about 1 in 2500 pregnancies. You are more likely to have a vasa previa if:
- you have a previous history of D & C
- you have a low-lying placenta (even corrected)
- you have an unusual placenta
- you are carrying more than one baby
- you experienced an IVF pregnancy
Examples:
The patient has a vasa previa in this pregnancy.

