Patients with certain problems are felt to be at risk for hemorrhage after child-birth and Interventional Radiology can play a role in the prevention and treatment of this significant condition. Primary post-partum hemorrhage occurs in 4-6% of pregnancies.
What Causes Post-Partum Hemorrhage?
The most common causes include uterine atony (reduced tone of the uterus after child birth), retained placenta, abnormal attachment of the placenta to the uterus (placenta accreta, placenta previa), and lower genital tract trauma.
Uterine Atony
Uterine atony is the most common cause of post-partum hemorrhage and occurs when the uterus fails to contract after birth. An abnormal attachment of the placenta is the second most common cause of post-partum hemorrhage.
This can be seen with placenta previa, which occurs when the placenta is found within the lowest part of the uterus and covers all or part of the cervix, or with placenta accreta, which occurs when the placenta attaches itself too deeply into the wall of the uterus.
Placenta Accreta Risk Factors
Risk factors for placenta accreta include placenta previa, prior myomectomy for fibroids, prior c-section, Asherman’s syndrome, submucosal fibroids, and maternal age older than 35 years. It is important to have a high degree of suspicion for placental problems in these patients since it is possible to take steps towards reducing the likelihood of significant bleeding if the problem is identified early.
How is a High-Risk Delivery Different from a Normal Delivery?
When these conditions are identified, a team can be put in place (which can include a high-risk OB-GYN, obstetrical anesthesia, interventional radiology, urology, etc.) so everyone is prepared for their role in the delivery.
As part of this team at Albany Medical Center, our Interventional Radiology group often sees patients with these placental abnormalities well in advance of their delivery to discuss our role in their care.
Diagnosis of Placental Abnormalities
- Ultrasound: Many placental abnormalities can be detected using ultrasound, which is a standard examination performed during pregnancy. However, some clinical suspicion is usually required to make this diagnosis.
- Pelvic MRI: Pregnant patients that are suspected of having a placental abnormality on the basis of an ultrasound are often further evaluated with an MRI. This test is safe to perform in pregnant patients since there is no radiation. It provides the definition of the uterus that is required to determine the position of the placenta within the uterus and depth of placental invasion into the wall of the uterus. The radiologists of Community Care Physicians do offer this service to pregnant patients felt to be at risk for these abnormalities.
Interventional Treatment of Post-Partum Hemorrhage
- Balloon Catheter Placement: At Albany Medical Center, our Interventional Radiologists routinely participate in the care of patients felt to be at high risk for post-partum hemorrhage due to placental abnormalities. This involvement typically comes in the form of placing balloon catheters in the main arteries bringing blood to the pelvis immediately prior to delivery. These catheters are placed in each femoral artery and passed into the internal iliac arteries. Once the baby has been delivered the balloons are inflated, which limits blood flow into the pelvis and allows the obstetrician to complete either the vaginal delivery or cesarean section with reduced bleeding. The catheters are then removed.
- Embolization: Embolization procedures are typically performed on an emergent basis in association with post-partum hemorrhage. An embolization procedure involves placing a catheter (tube) into the femoral artery and advancing that catheter using x-rays for guidance into the arteries bringing blood to the uterus. These are the uterine arteries. Once the catheter is in place, a substance called gelfoam can be injected into the uterine arteries to stop any bleeding coming from these arteries. Excellent success rates have been reported in association with this procedure when performed in this setting. Since patients in this situation are obviously in their childbearing years, one question that arises frequently is whether or not embolization can preserve a patient’s future fertility. What is known is that most patients reported in the medical literature have resumed normal menstrual cycles and that successful and uneventful pregnancies have occurred.
