Tests and diagnosis

By Mayo Clinic Staff

Placenta previa is diagnosed through ultrasound, either during a routine prenatal appointment or after an episode of vaginal bleeding.

A definitive diagnosis may require a combination of abdominal ultrasound and transvaginal ultrasound, which is done with a wand-like device placed inside your vagina. Your health care provider will take care with the position of the transducer in your vagina so as not to disrupt the placenta or cause bleeding. In rare instances, magnetic resonance imaging (MRI) may be used to clearly determine placental location.

If your health care provider suspects placenta previa, he or she will avoid routine vaginal exams to reduce the risk of heavy bleeding. You may need additional ultrasounds to check the exact location of your placenta before delivery. Your baby's heartbeat may be tracked as well.

May 09, 2014