Placenta Previa

Placenta Previa is a condition where the placenta lies low in the uterus and partially or completely covers the cervix. The placenta may separate from the uterine wall as the cervix begins to dilate (open) during labor.

How common is placenta previa?

Placenta previa affects about 1 in 200 pregnant women in the third trimester of pregnancy.

Placenta previa is more common in women who have had one or more of the following:

  • More than one child
  • A cesarean birth
  • Surgery on the uterus
  • Twins or triplets

What are the different types of placenta previa?

  • Complete previa: the cervical opening is completely covered
  • Partial previa: a portion of the cervix is covered by the placenta
  • Marginal previa: extends just to the edge of the cervix

What are the symptoms of placenta previa?

Signs and symptoms of placenta previa vary, but the most common symptom is painless bleeding during the third trimester. Other reasons to suspect placenta previa would be:

  • Premature contractions
  • Baby is breech, or in transverse position
  • Uterus measures larger than it should according to gestational age

What is the treatment for placenta previa?

Once diagnosed, placenta previa will usually require bed rest for the mother and frequent hospital visits. Depending on the gestational age, steroid shots may be given to help mature the baby’s lungs. If the bleeding cannot be controlled, an immediate cesarean delivery is usually done regardless of the length of the pregnancy. Some marginal previas can be delivered vaginally, although complete or partial previas would require a cesarean delivery.

Most physicians recommend women who are experiencing placenta previa to:

  • Avoid intercourse
  • Limit traveling
  • Avoid pelvic exams

What causes placenta previa?

The exact cause of placenta previa is unknown. However, the following can increase your risk:

  • If over the age of 35
  • Had more than four pregnancies
  • Have a history of uterine surgery (regardless of incision type)

How do I cope with placenta previa?

With all the excitement and anticipation of a healthy delivery, receiving the diagnosis of placenta previa can be a very shocking and frustrating experience. There are support groups for bed rest mothers and even some for mothers with placenta previa. They are available to help you through this difficult time. Your doctor, midwife, or doula should be able to assist you with finding support groups or other women who have also had placenta previa.

Last Updated: 05/2007

Compiled using information from the following sources:

Danforth’s Obstetrics and Gynecology Ninth Ed. Scott, James R., et al, Ch. 20.

March of Dimes, http://www.marchofdimes.com/home.asp