Rh-Negative Mother with Anti-D at Delivery: A Case Study

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Author: Pat Letendre, M.Ed.
Reviewer: Laurie Bjerklie, MA, MLS(ASCP)CM

If you have completed the course, Hemolytic Disease of the Fetus and Newborn, you will enjoy working through a case that provides real-world application of what you have learned.

This case study presents an opportunity to review perinatal testing programs and the crucial role of RhIg in preventing hemolytic disease of the fetus and newborn (HDFN) due to anti-D. The case also examines practical aspects of routine serologic testing involving neonates and women who have received RhIg during pregnancy.

You will be guided through laboratory findings that need to be interpreted and resolved; be presented with current best practices in perinatal testing programs; review the characteristics of RhIg and its use in pregnancy; review and investigate key issues associated with detection of anti-D in women who have received antenatal RhIg; and learn about crossmatch and LIS policies related to RhIg-derived passive anti-D.

Continuing Education Credits

Objectives

  • Discuss the history and properties of RhIG, its criteria for administration, and dosage calculation.
  • Interpret serologic tests done on the mother and fetus/newborn as part of perinatal testing programs, including antibody identification.
  • Identify best practices for serologic and other tests used in perinatal testing programs.
  • Describe the principles, uses, and limitations of the rosette test, Kleihauer-Betke test, and flow cytometry in Rh prevention programs.
  • Discuss key issues associated with the detection of anti-D in mothers who have received antenatal RhIG.
  • Identify crossmatch and LIS policies and practices related to RhIG-derived passive anti-D.

Course Outline

  • Case Scenario
      • Introduction
      • Case Presentation
    • Initial Serologic Test Results
      • ABO/Rh Typing and Antibody Screen
      • Which of the following are possible causes of the positive antibody screen?
      • Why might screen cell #2 be reacting stronger than screen cell #1?
      • Antigram
      • Which of the possible causes is the most likely cause of the positive antibody screen?
  • Perinatal Testing Programs
      • Perinatal Testing Programs
      • Immunogenicity
      • Routine Serologic Tests: Mother
      • Routine Serologic Tests: Newborn Protocols
      • Routine Serologic Tests: Newborn Protocols, continued
  • Interpreting Initial Serologic Tests
      • Interpreting Initial Serologic Tests
      • Antibody Exclusion Protocol (General)
      • Initial Antibody Exclusions
      • Antibody Exclusion Protocols (RhIG)
      • Passive or Active Immunization?
      • RhIG-Derived Anti-D Reaction Strength
      • Factors Affecting RhIG Reaction Strength
      • How Long Can RhIG Be Detected?
      • Which of the following factors is most likely to cause a false-negative antibody screen following RhIG injection?
      • True or False: A pregnant patient has been injected with RhIG antenatally and has a positive antibody screen at delivery. If the antibody has been con...
      • True or False: A pregnant patient who received RhIG at 28 weeks gestation has a positive antibody screen at delivery. If the antibody has been confirm...
  • Follow-up Serologic Tests
      • How Much Testing?
      • Mini-Panel Antibody Exclusion
      • True or False: Using the guidelines in the antibody exclusion protocol, all unexcluded antibodies (anti-C, E, K, Fyb, Jka, N, s) have been excluded by...
  • Post-Delivery Testing
      • Serologic Tests on Newborn
      • True or False: The newborn's ABO group is invalid because no reverse (serum) group was set up with A1 and B cells.
      • True or False: The newborn's Rh(D) type is invalid because the DAT is positive.
      • True or False: The positive DAT on the newborn means that the infant probably has clinically significant hemolysis.
      • Newborn's Clinical Status
      • Is the mother a candidate for RhIG?
      • Screening for Fetomaternal Hemorrhage (FMH)
      • Quantifying FMH
      • Kleihauer-Betke (KB) Test
      • Flow Cytometry
      • Calculating RhIG Dosage
      • Assessing FMH and RhIG Dosage
      • Which of the following tests are suitable for quantifying the size of fetomaternal hemorrhage (FMH)?
      • True or False: Facilities that use a special calculation for RhIG dosage add one vial, regardless if they round up or round down.
  • Summary and Conclusions
      • Case Summary
  • When Transfusion Is Necessary
      • Crossmatch Issues
      • Crossmatch Implications of RhIG-Associated Passive Anti-D
      • Introduction to Crossmatch Practices Related to RhIG
      • LIS Issues Related to RhIG
      • Examples of Crossmatch Practices Related to RhIG
      • True or False: Blood safety standards, such as AABB Standards, directly specify that an electronic crossmatch cannot be done when an Rh-negative mothe...
  • Further Reading
      • Further Reading
  • References
      • References

Additional Information

Level of Instruction: Intermediate
Intended Audience: Medical laboratory scientists, technicians, and pathologists. This course is also appropriate for medical laboratory science students and pathology residents.
Author Information: Pat Letendre, MEd is a laboratory technologist, educator, and consultant. Currently, she consults full-time in the areas of transfusion medicine, education, and professional development. Ms. Letendre is the Webmaster for Canada's transfusion safety officers and the TraQ website coordinator. She holds a Master of Education degree in adult education from the University of Alberta and a Bachelor of Science degree from the University of Manitoba.  
Reviewer Information: Laurie Bjerklie, MA, MLS(ASCP)CM is currently an Education Developer for MediaLab and LabCE. She earned a B.S. in Medical Laboratory Science from the University of North Dakota and an M.A. in Curriculum and Instruction from Saint Xavier University. She has over 15 years of experience in higher education and has held program director and faculty positions in both MLT and MLS programs. She most recently served as the Program Manager of Medical Laboratory Science at Saint Louis University.

This course is part of:
Compliance & CE
Antibody screen cells