Placenta Previa – Pathophysiology for nurses
What is Placenta Previa
Placenta previa is when the placenta either partially or completely covers the opening of the cervix of the pregnant patient. Severe bleeding can occur with placenta previa before, during or even after delivery.
Oxygen and nutrients are supplied to the fetus by the placenta. The placenta also removes waste products from the babies blood. All this activity is done via the umbilical cord. Usually the placenta will attach to the uterus of the pregnant patient at the side or top of the uterus, in placenta previa however, the placenta attaches to the lower part of the uterus.
Patients with placenta previa are usually placed on physical restriction during part of the pregnancy and may require a cesarean section at the time of delivery.
Signs and Symptoms
Painless vaginal bleeding is the hallmark sign of placenta previa. The bleeding may be scant or heavy and can stop at any time without treatment. It may return several days to weeks later. Although rare, it is also possible that some patients may experience contractions.
It is important to remind pregnant patients that if they experience vaginal bleeding to contact their healthcare provider right away.
Risk Factors and Causes
Once the embryo implants itself in the uterus, the placenta will start to develop. If the implantation occurs in the lower part of the uterus, it may grow and develop over the cervix causing a placenta previa.
Placenta previa is usually diagnosed by the 2nd trimester by ultrasound exam. Placenta previa has been associated with:
- Age 35 or older at time of pregnancy
- Scaring of uterus from previous surgeries (C-section, removal of uterine fibroids, D&C)
- Large placenta
- Previous births
- Prior or past placenta previas
- Use of cocaine
The healthcare team will be monitoring for the following complications:
- Bleeding: the bleeding can be severe enough to become life-threatening. Hemorrhage may happen during labor and/or delivery. Hemorrhage is also possible after delivery.
- Preterm birth: If the bleeding is severe enough the physician may do an emergency C-section.
The diagnosis of placenta previa is usually done by abdominal ultrasound and trans-vaginal ultrasound. The benefit of the trans-vaginal ultrasound is visualization of the placental location when the placenta is thought to be low lying. An MRI may also be done to determine where the placenta is located.
Routine vaginal exams may be avoided to reduce the risk of bleeding.
Once the patient is diagnosed with placenta previa, they will usually be placed on bed rest and more frequent checkups. Steroid shots may be given depending on the gestational age of the baby to help the lungs mature.
If the bleeding can not be controlled, an emergency C-section may be done regardless of the length of the pregnancy to avoid hemorrhage.
While marginal previas may be delivered vaginally. A c-section is required for a partial or complete previa.
It is important for the healthcare team to always anticipate possible massive hemorrhage and preterm delivery with placenta previas.
Here is our podcast for Placenta Previa
Nursing Care Plan
1. Deficient Fluid volume related to excessive vaginal bleeding secondary to abnormal implantation and disruption of the placenta.
During hospitalization the patient will maintain adequate fluid volume and exhibit normovlemic status as evidenced by stable vital signs.
|Assess, chart and report amount of vaginal bleeding; weight pads||This intervention will assist in estimation of blood loss and will help to differentiate old blood versus active bleeding.|
|Place mother in left side lying position when resting. When awake place in semi-fowler position or position where pelvis is slightly elevated.||This improves blood flow to the fetus, uterus, heart, and kidneys.|
|Measure vital signs q 4 hours, or more often if outside of normal parameters for the patient.||HR is usually elevated in loss of fluid from the body. Sign of dehydration must be monitored carefully as the patient can go into shock.|
|Replace fluid orally or via IV as ordered by physician||This will endure that the patient is staying hydrated and will also help the body maintain homeostasis.|
2. Risk for Impaired gas exchange related to decreased surface area of oxygen due to site of placental attachment.
Within 4-8 hours of nursing interventions, the client will be able to verbalize the causative factors of appropriate interventions.
|Monitor pulse oximetry and report O2 saturation <92%.||These signs of symptoms of respiratory distress necessitate prompt interventions.|
|Assess respiratory rate. Monitor if there is an increase in anxiety, shortness of breath, cyanosis. Report any on-toward signs and symptoms immediately.||An O2 saturation of less than 92% may detect hypoxia and signals the need for supplemental oxygen.|
|Encourage deep breathing exercises and administer oxygen if indicated||Increases oxygen delivery to the body by mobilizing secretions and improving ventilation.|
Other possible nursing diagnosis:
Anxiety/Fear related to threat of change on health or death (perceived or actual) to the unborn child or self.
Risk for bleeding related to pregnancy related conditions
Activity intolerance related to bed rest prescribed during pregnancy
Please follow your facilities guidelines and policies and procedures. The medical information on this site is provided as an information resource only, and is not to be used or relied on for any diagnostic or treatment purposes. This information is not intended to be nursing education and should not be used as a substitute for professional diagnosis and treatment.