Updated: 2/19/2020

Rh Hemolytic Disease of the Newborn

0%
Topic
Review Topic
0
0
N/A
N/A
Questions
0 2
0
0
Topic
Snapshot
  • A 32-year-old G1P0 woman presents to the emergency room with contractions. She was found to be Rh-negative and her husband’s Rh status is unknown. Fetal ultrasound shows no signs of edema or ascites. After the Kleihauer-Betke test, she is given the appropriate dose of Rh IgG.
Introduction
  • Overview
    • Rh hemolytic disease of the newborn is caused by Rh incompatibility
    • maternal anti-Rh IgG antibodies cross the placenta and destroy fetal Rh-positive red blood cells
  • Epidemiology
    • incidence
      • 15% of the population is Rh-negative
    • risk factors
      • history of prior blood transfusion
      • previous pregnancy
      • mother is Rh-negative, and father is Rh-positive or unknown
      • prior administration of Rh IgG (RhoGam)
      • history of invasive obstetric procedures
  • Pathogenesis
    • mechanism    
      • Rh factor is a red blood cell antigen
      • when an Rh-negative mother is pregnant with an Rh-positive fetus, the mother is exposed to Rh-positive red blood cells and leads to maternal antibody production (IgG) against the foreign Rh antigen
      • as IgG can cross the placenta, subsequent pregnancy with Rh-positive fetus will result in fetal alloimmune-induced hemolytic anemia
      • development of antibody depends on volume of transplacental crossover of red blood cells, concurrent presence of ABO incompatibility, and extent of maternal immune response
      • breakdown of red blood cells causes elevation of bilirubin
Presentation
  • Symptoms
    • hemolytic anemia
  • Physical exam
    • inspection
      • jaundice
      • pallor
Imaging
  • Fetal ultrasound
    • indication
      • suspected Rh incompatibility
    • findings
      • fetal ascites and edema
Studies
  • Serum labs
    • hyperbilirubinemia
    • low hematocrit
    • elevated reticulocyte count
    • positive direct Coombs test in fetus; positive indirect Coombs test in the mother
  • Rosette test
    • initial test to test for fetal-maternal hemorrhage
  • Kleihauer-Betke test
    • measures fetal red blood cells in utero in maternal circulation to determine dose of RhoGAM
Differential
  • ABO incompatibility
    • key distinguishing factor
      • typically less severe
Treatment
  • Medical
    • maternal anti-D immune globulin (Rh IgG or RhoGAM) administration
      • indication
        • if mother is Rh-negative and has not been sensitized previously, given at 28th week of pregnancy, if possible, and 72 hours after birth
        • external cephalic version
        • amniocentsis
        • ectopic pregnancy
    • exchange transfusion
      • indications
        • erythroblastosis fetalis
        • hydrops fetalis
        • kernictus
Complications
  • Kernicterus secondary to hyperbilirubinemia
    • loss of Moro reflex
    • posturing
    • poor feeding
    • seizures
  • Erythroblastosis fetalis
    • most severely, can manifest as hydrops fetalis with high output cardiac failure, edema, and death
    • indication for immediate delivery and exchange transfusion
Topic Rating

Please rate topic.

Average 5.0 of 3 Ratings

 

Questions (2)
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
Topic COMMENTS (14)
Private Note