Placenta Previa

Maternal Fetal Health

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Placenta Previa

 

Overview:

Placenta previa is an uncommon pregnancy complication that can cause excessive bleeding before or during delivery. Placenta previa occurs when the placenta attaches to the lower part of the uterine wall, partially or totally covering the cervix. When the cervix starts to open in preparation for labor, the placenta is detached, which can trigger severe vaginal bleeding.  

 

                        

 

1. Symptoms: 

The main symptom of placenta previa is sudden bleeding from the vagina. Some women have cramps, too. 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. 

 

2. Causes:

Placenta previa occurs when the placenta implants in the lower part of the uterus, covering or being near the cervical opening (the os). The exact cause is not entirely understood, but several factors are thought to contribute to its development:

  1. Previous Cesarean Section: One of the most significant risk factors, as scarring from a previous C-section may affect the normal implantation of the placenta, leading to abnormal placental positioning.

  2. Multiple Pregnancies (Multiparity): Women who have had multiple pregnancies are at higher risk due to changes in the uterine lining that can affect how and where the placenta implants.

  3. Advanced Maternal Age: Women over the age of 35 are at increased risk, possibly due to changes in uterine structure or blood flow.

  4. Uterine Abnormalities or Scarring: Previous uterine surgeries, infections, or structural abnormalities may disrupt the normal implantation process.

  5. Multiple Gestations: Carrying twins or other multiples increases the likelihood of placenta previa, as there may be more competition for space in the uterus.

  6. Smoking and Substance Use: Smoking has been linked to abnormal placental implantation, as it can affect blood flow to the uterus.

  7. Increased Placental Size: Conditions like gestational diabetes or hypertension may lead to a larger placenta, increasing the likelihood of it being improperly positioned.

  8. Previous Placenta Previa: Women who had placenta previa in a previous pregnancy are at an increased risk of having it again.

3. Treatment: 

The health care provider will carefully consider the risk of bleeding against early delivery of the 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, the doctor may recommend:  

  • Reducing activities 

  • Bed rest 

  • Pelvic rest, which means no sex, no tampons, and no douching  

 

Other treatments they may receive: 

  • Blood transfusions 

  • Medicines to prevent early labor 

  • Medicines to help pregnancy continue to at least 36 weeks 

  • Shot of special medicine called Rhogam if your blood type is Rh-negative 

  • Steroid shots to help the baby's lungs mature  

An emergency C-section may be done if the bleeding is heavy and cannot be controlled. 

 

4. Effect on Neonate: 

Health risks for infants may include: 

  • Preterm birth 

  • Congenital abnormalities 

  • Respiratory Distress Syndrome 

  • Low birth weight 

  • Anemia 

  • Still born 

 

5. Maternal Risks:

  • Hemorrhaging 

  • Hysterectomy 

  • Shock 

  • Death 

 

6. Prognosis: 

The biggest risk is severe bleeding that can be life threatening to the mother and baby. If the mother has severe bleeding, the baby may need to be delivered early, before major organs, such as the lungs, have developed. 

 

7. Complications: 

  • Failure to monitor an infant after placenta previa has been diagnosed, which can lead to fetal hypoxia 

  • Failure to conduct ultrasounds and formulate a correct plan of action for mother with placenta previa 

  • Attempting a normal delivery when complete placenta previa is present 

  • Delaying a schedule C-section 

8. What should an RT be ready to do in a delivery with placenta previa?

Airway management may be required if the neonate needs resuscitation. Ensure all resuscitation equipment is ready, including neonatal intubation kits, CPAP, oxygen, and suction devices.

Prepare for possible intubation if the infant is born in poor condition or has difficulty breathing immediately after delivery.

  1. Monitoring and Support:

    • Be prepared to monitor oxygenation and ventilation in the neonate, as hypoxia can occur due to placental insufficiency or cord complications.

    • Pulse oximeter and capnography should be readily available to assess the infant's oxygenation and CO2 levels.