Placenta previa

Reproduction: Late Pregnancy

Bleeding

Placenta Previa & Placental Abruption
Becky Hermann MSN, RN

Objectives

  1. Compare and contrast the signs and symptoms of placenta previa and placental abruption.

  2. Identify the risk factors for placenta previa.

  3. Explain the maternal and fetal complications associated with placenta previa.

  4. Outline the role of the nurse when caring for a woman experiencing placenta previa.

  5. Identify the risk factors for placental abruption.

  6. Explain the maternal and fetal complications associated with placental abruption.

  7. Outline the role of the nurse when caring for a woman experiencing placental abruption.

Placenta Previa

Definition

  • Placenta previa is a condition where the placenta implants abnormally in the lower uterine segment, either near or over the internal cervical os.

Classification of Placenta Previa

Based on location and degree of cervical coverage:

  • Complete (Total): The placenta completely covers the cervix.

  • Incomplete or Partial: The placenta partially covers the cervix.

  • Marginal: The placenta is attached in the lower uterine segment but does not cover the cervix (usually ≤ 2.5 cm from the cervix).

  • Low-Lying Placenta: The placenta is attached to the lower uterine segment but the exact relationship with the internal cervical os is undetermined.

  • Bleeding occurs during the third trimester as the cervix begins to dilate and efface.

Incidence & Etiology

  • Occurs in 1 in 200 term pregnancies.

  • More common in non-white mothers.

  • More prevalent with a male fetus.

  • No exact known cause; usually diagnosed by ultrasound in the 2nd trimester, specifically through transvaginal ultrasound.

Risk Factors for Placenta Previa

  • Advanced Maternal Age: > 35 years old

  • Previous Placenta Previa: Personal history of placenta previa in prior pregnancies.

  • History of Previous C-section: Increased risk due to uterine scarring.

  • Prior D&C: History of dilation and curettage procedures.

  • Multiparity: Having multiple pregnancies increases risk.

  • Multiple Pregnancy: Involves twins or more, raising the risk.

  • Maternal Smoking or Cocaine Use: Substances that can compromise placental position.

  • Pregnancy resulting from Assisted Reproductive Technologies.

Signs & Symptoms of Placenta Previa

  • Painless bright red bleeding in the 2nd and 3rd trimesters occurs in 90% of cases.

  • Maternal vital signs may remain normal.

  • Characterized by a soft, relaxed, non-tender uterus with normal tone.

  • The presenting part of the fetus usually remains high in the abdomen.

  • Fundal height can appear greater than expected.

  • Fetal malpresentation (breech and transverse or oblique lie) is common.

  • Diagnosis implemented through transabdominal or transvaginal ultrasound.

Maternal Complications of Placenta Previa

  • Significant Blood Loss: Can lead to hypotension, nausea, tachycardia, shortness of breath, and decreased placental perfusion.

  • Decreased Urine Output: Reflects changes in renal perfusion.

  • Morbidly Adherent Placenta: Increased risk of placenta accreta, increta, or percreta.

  • C-section Complications: Associated risks include trauma to adjacent organs, anesthesia reactions, DVTs, and infection.

  • Potential need for hysterectomy due to uncontrolled bleeding.

  • Increased Risk for Placental Abruption: Vulnerability due to abnormal implantation.

  • Maternal Stress and Anxiety: Women are instructed to call 911 if bleeding occurs.

Fetal Complications of Placenta Previa

  • Prematurity: Likely associated with early delivery due to complications.

  • Low Birth Weight: Secondary to potential placental insufficiency.

  • Respiratory Distress Syndrome: A risk due to prematurity.

  • Intrauterine Growth Restriction (IUGR): Possibility due to abnormal placental function.

  • Fetal Anomalies: Risk associated with complications from previa.

  • Decreased Placental Perfusion can lead to fetal hypoxemia and, in severe cases, fetal death.

Management & Treatment of Placenta Previa

  • Bedrest with Bathroom Privileges: Limit physical activity to reduce complications.

  • Pelvic Rest: Avoidance of vaginal intercourse.

  • Frequent Ultrasounds: Necessary to monitor placental location.

  • Corticosteroids: Indicated if < 34 weeks to promote fetal lung maturity.

  • Use of Tocolytics may help prevent preterm labor.

  • Iron Supplementation and dietary education to address anemia.

  • Patient Education: Emphasizing awareness and preparedness for complications.

  • Preparing patients for emergency transport to the hospital if needed.

  • Goal: To carry the pregnancy to term, if possible.

Nursing Interventions for Placenta Previa

  • When women present to labor and delivery (L&D):

    • Do NOT perform vaginal exams.

    • Call the provider for immediate assistance.

    • Prepare for emergency C-section if required and possible blood transfusion.

    • Continuous fetal monitoring.

    • Establish at least one 18 or 20 gauge IV for fluids and potential transfusions.

    • Conduct labs including hemoglobin, hematocrit, platelet count, and coagulation studies.

    • Perform a type and screen for blood, and type and crossmatch if transfusion is likely.

    • Insert a Foley catheter for strict intake and output monitoring.

    • Administer tocolytics if uterine contractions are present.

    • Prepare for maternal and neonatal resuscitation as necessary.

    • Provide emotional support and educate the patient and family about the condition.

Abruptio Placentae

Definition

  • More commonly termed Placental Abruption: This refers to the premature separation of the placenta from the uterus before the birth of the baby.

Classification of Placental Abruption

  • Grade 1:

    • Mild Separation (10%-20%)

    • Usually presents with external vaginal bleeding, minimal total blood loss (<500 mL), dark red blood color, and absent to moderate shock.

    • Uterus is generally non-tender.

  • Grade 2:

    • Moderate Separation (20%-50%)

    • Presents with external bleeding, total blood loss between 500-1500 mL, dark red blood, and moderate shock.

    • There may be some tenderness and occasional DIC.

  • Grade 3:

    • Severe Separation (>50%)

    • Presents with absent to moderate external bleeding, over 1500 mL total blood loss, dark red blood, and usually severe shock.

    • Typical findings include agonizing, unremitting uterine pain and frequent DIC with a rigid uterus.

Diagnosis of Placental Abruption

  • Primarily based on clinical presentation.

  • Ultrasound may detect some abruptions but at least 50% may not be visible.

  • Diagnosis is confirmed after birth through visual inspection and microscopic examination.

Risk Factors for Placental Abruption

  • Moms with gestational or chronic hypertension.

  • Smoking, cocaine or meth use, leading to vasoconstriction.

  • Maternal experience of premature rupture of membranes (PROM).

  • Trauma to the abdomen resulting from motor vehicle accidents, domestic violence, or falls.

  • Pregnancies with twins, triplets, etc.

  • History of placental abruption in previous pregnancies.

Signs & Symptoms of Placental Abruption

  • Symptoms will vary with the degree of separation:

    • Sudden onset of symptoms, which may include internal or external vaginal bleeding characterized by dark red blood.

    • Abdominal Pain: Ranges from mild to severe and may be steady.

    • Firm Uterus: Typically presenting with contractions or tetany and an enlarged feel.

    • Indicators of fetal distress may be present.

Maternal Complications of Placental Abruption

  • Hemorrhage and Shock: Severe bleeding necessitating prompt intervention.

  • Disseminated Intravascular Coagulation (DIC): Serious complication that may develop.

  • Need for Blood Transfusion: Due to significant blood loss.

  • End-Organ Damage: Potential impact on organs due to hypovolemic shock.

  • Risk of Rh Sensitization: Especially in Rh-negative mothers.

  • Potential need for C-section and possible peripartum hysterectomy.

  • Couvelaire Uterus: A condition wherein the uterus becomes infiltrated with blood due to placental separation.

  • Possible Death: Though rare, significant complications can lead to maternal mortality.

Lab Findings Associated with Placental Abruption

  • Positive Apt Test indicating blood in amniotic fluid.

  • Decreased Hemoglobin & Hematocrit levels.

  • With DIC, laboratory findings include: low platelet count, elevated D-dimer, decreased fibrinogen concentration, and prolonged prothrombin time (PT).

  • Positive Kleihauer-Betke (KB) test if fetal-to-maternal bleeding occurs (transplacental hemorrhage).

Fetal Complications of Placental Abruption

  • Potential Fetal Growth Restriction (IUGR).

  • Occurrence of Oligohydramnios.

  • Possibility of Preterm Delivery.

  • Hypoxemia: Decreased oxygen delivery may lead to complications.

  • Risk for Neurodevelopmental Disorders, such as Cerebral Palsy.

  • Severe cases can lead to Fetal Demise (Stillbirth) and Neonatal Death.

Medical Management of Placental Abruption

  • Management is contingent on severity, fetal maturity, and status.

  • Recommended Maternal Bedrest to reduce further complications.

  • Continuous Monitoring: Frequent non-stress tests (NSTs), biophysical profiles, labs, ultrasounds, fundal height, and abdominal measurements are essential.

  • Administer Corticosteroids to mature fetal lungs if the pregnancy is between 20-34 weeks and both mother and fetus are stable.

  • Prepare for Immediate Delivery if necessary.

  • For mild bleeding, induction for vaginal birth may be an option.

  • For severe bleeding, emergent C-section is required if >34 weeks or moderate-severe bleeding is present.

Nursing Interventions for Placental Abruption - Delivery

  • Continuous External Fetal Monitoring to ensure fetal well-being.

  • Establish at least one large-bore intravenous (IV) line for fluid access and to facilitate transfusion if needed.

  • Monitor maternal vital signs closely, specifically watching for increased heart rate and decreased blood pressure.

  • Conduct serial labs including hemoglobin & hematocrit and coagulation studies.

  • Use a Foley catheter for continuous assessment of urine output.

  • Administer fluid replacement as necessary.

  • Prepare for blood product transfusions if indicated.

  • Be ready for maternal and neonatal resuscitation if complications arise.

  • Provide education and emotional support to the patient and their family.

Comparative Summary of Placenta Previa and Abruptio Placentae

Placenta Previa

  • Signs: Painless bright red bleeding (vaginal), relaxed soft non-tender uterus, visible bleeding.

  • Uterus: Soft and non-tender, episodes of bleeding may occur post-intercourse.

  • Fetal Position: Often presents with abnormal fetal position while maintaining normal fetal heart rate (FHR).

Abruptio Placentae

  • Signs: Dark red bleeding, increased fundal height, tender uterus, strong abdominal pain or contractions, concealed bleeding, hard abdomen, may experience DIC, and potential fetal distress.

References

  • Cleveland Clinic. (n.d.). Placenta previa: Symptoms, causes & treatments. Retrieved from https://my.clevelandclinic.org/health/diseases/24211-placenta-previa

  • Nurse Mo. (2023, August 4). Placental abruption vs placenta previa NCLEX® review. Retrieved from https://straightanursingstudent.com/placental-abrution-vs-placenta-previa-nclex-review/

  • Perry, S. E., Lowdermilk, D. L., Cashion, K., Alden, K. R., Olshansky, E., & Hockenberry, M. J. (2023). Maternal Child Nursing Care (7th ed.). Elsevier.

  • YouTube. (2018). Abruptio Placenta vs.Placenta Previa. Retrieved from https://www.youtube.com/watch?v=FDRSPppWe2k.