Placenta previa is a pregnancy complication that occurs when the placenta extends over the cervix. It is a common cause of bleeding in the later stages of pregnancy, putting mother and baby at risk.
What Happens in Placenta Previa?
The placenta is an organ that develops in the uterus (the womb) during pregnancy to provide oxygen and nutrients to your baby. Normally, the placenta attaches along the body (top, front or back wall, or sides) of the uterus. During delivery, the baby delivers through the open cervix into the birth canal.
In women with placenta previa, the placenta is attached low in the uterus and extends over the cervix. As the cervix thins and opens during pregnancy and labor, it can cause the placenta to bleed.
Women with placenta previa usually require a cesarean delivery (c-section) to avoid the risk of severe bleeding during a vaginal delivery.
Are You at Risk?
Placenta previa is more common in women who:
- Have had a previous cesarean delivery
- Are pregnant with more than one fetus
- Have had several previous pregnancies
- Have had uterine surgery or procedures that scarred the lining of the uterus
- Had placenta previa in a previous pregnancy
- Smoke cigarettes or use cocaine
- Are over the age of 35
Primary Symptom: Painless Vaginal Bleeding
The primary symptom of placenta previa is bright-red bleeding without pain, typically after 20 weeks of pregnancy. The bleeding can range from light to life-threatening. It may stop and start again.
In some cases women may experience contractions or cramps in addition to the bleeding.
Diagnosis through Ultrasound
Placenta previa is diagnosed through an ultrasound examination. Women may not know they have the condition until it is discovered during a routine ultrasound scan.
Treatment depends on the severity of the bleeding, the stage of pregnancy, and the condition of mother and baby.
The range of treatment includes:
- No pelvic exams or intercourse
- Medications to prevent early labor
- Steroid injections to help the baby's lungs mature, in case of early delivery
- A planned cesarean delivery (c-section) as soon as the baby can be safely delivered, typically after 36-37 weeks
- Hospitalization for closer monitoring, if needed
- IV fluids and blood transfusions, in cases of heavy bleeding
- An emergency c-section if the bleeding is heavy and can’t be controlled with treatment and hospitalization
Possible complications of placenta previa include:
- Breech or abnormal position of the fetus
- Premature delivery
- Increased risk of placenta accreta spectrum (PAS) or “accreta”, a rare, potentially life-threatening complication that occurs when the placenta grows too deeply into the uterus and is unable to detach at childbirth. Morbidly adherent placenta can cause massive hemorrhage and the need for a hysterectomy during a cesarean delivery.
Specialized Care for Improved Outcomes
If placenta previa is diagnosed or suspected, your specialized care should include:
- A carefully timed, well-planned delivery that minimizes the risks of blood loss and premature birth
- Advanced imaging technologies and expertise
- A multidisciplinary medical and surgical team experienced in managing these pregnancies and deliveries
- Delivery at a state-of-the-art facility with access to critical support resources, including 24/7 blood bank and transfusion services
- A contingency plan for emergency delivery
- Immediate access to a neonatal intensive care unit (NICU) after birth, if needed
- Close collaboration with your current healthcare providers