Placenta previa is a problem of pregnancy in which the placenta grows in the lowest part of the womb (uterus) and covers all or part of the opening to the cervix.
The placenta grows during pregnancy and feeds the developing baby. The cervix is the opening to the birth canal.
Vaginal bleeding - placenta previa; Pregnancy - placenta previa
During pregnancy, the placenta moves as the womb stretches and grows. It is very common for the placenta to be low in the womb in early pregnancy. But as the pregnancy continues, the placenta moves to the top of the womb. By the third trimester, the placenta should be near the top of the womb, so the cervix is open for delivery.
Sometimes, the placenta partly or completely covers the cervix. This is called a previa.
There are different forms of placenta previa:
Placenta previa occurs in 1 out of 200 pregnancies. It is more common in women who have:
Women who smoke, use cocaine, or have their children at an older age may also have an increased risk.
The main symptom of placenta previa is sudden bleeding from the vagina. Some women also have cramps. The bleeding often starts near the end of the second trimester or beginning of the third trimester.
Bleeding may be severe and life threatening. It may stop on its own but can start again days or weeks later.
Labor sometimes starts within several days of the heavy bleeding. Sometimes, bleeding may not occur until after labor starts.
Your provider will carefully consider the risk of bleeding against early delivery of your baby. After 36 weeks, delivery of the baby may be the best treatment.
Nearly all women with placenta previa need a C-section. If the placenta covers all or part of the cervix, a vaginal delivery can cause severe bleeding. This can be deadly to both the mother and baby.
If the placenta is near or covering part of the cervix, your provider may recommend:
Nothing should be placed in the vagina.
You may need to stay in the hospital so your health care team can closely monitor you and your baby.
Other treatments you may receive:
An emergency C-section may be done if the bleeding is heavy and cannot be controlled.
Steven Clark is a Neonatologist and an Obstetrics and Gynecologist in Salt Lake Cty, Utah. Dr. Clark has been practicing medicine for over 43 years and is rated as an Elite doctor by MediFind in the treatment of Placenta Previa. He is also highly rated in 4 other conditions, according to our data. His top areas of expertise are Placenta Previa, Hysterectomy, Preeclampsia, and Pulmonary Embolism. He is licensed to treat patients in Utah. Dr. Clark is currently accepting new patients.
Karin Fox is an Obstetrics and Gynecologist and a Neonatologist in Houston, Texas. Dr. Fox has been practicing medicine for over 17 years and is rated as an Elite doctor by MediFind in the treatment of Placenta Previa. She is also highly rated in 2 other conditions, according to our data. Her top areas of expertise are Placenta Previa, Hysterectomy, Premature Infant, and Autosomal Dominant Hypocalcemia. She is board certified in Obstetrics/gynecology and licensed to treat patients in Texas. Dr. Fox is currently accepting new patients.
Shigeki Matsubara is in Shimotsuke, Japan. Matsubara is rated as an Elite expert by MediFind in the treatment of Placenta Previa. He is also highly rated in 20 other conditions, according to our data. His top areas of expertise are Placenta Previa, Hysterectomy, Hyperemesis Gravidarum, and Neonatal Ovarian Cyst.
The biggest risk is severe bleeding that can be life threatening to the mother and baby. If you have severe bleeding, your baby may need to be delivered early, before major organs, such as the lungs, have developed.
Call your provider if you have vaginal bleeding during pregnancy. Placenta previa can be dangerous to both you and your baby.
Francois KE, Foley MR. Antepartum and postpartum hemorrhage. In: Landon MB, Galan HL, Jauniaux ERM, et al, eds. Gabbe's Obstetrics: Normal and Problem Pregnancies. 7th ed. Philadelphia, PA: Elsevier; 2021:chap 18.
Hull AD, Resnik R, Silver RM. Placenta previa and accreta, vasa previa, subchorionic hemorrhage, and abruptio placentae. In: Resnik R, Lockwood CJ, Moore TR, Greene MF, Copel JA, Silver RM, eds. Creasy and Resnik's Maternal-Fetal Medicine: Principles and Practice. 8th ed. Philadelphia, PA: Elsevier; 2019:chap 46.
Salhi BA, Nagrani S. Acute complications of pregnancy. In: Walls RM, Hockberger RS, Gausche-Hill M, eds. Rosen's Emergency Medicine: Concepts and Clinical Practice. 9th ed. Philadelphia, PA: Elsevier; 2018:chap 178.