Anti-D in Rh positive pregnancies

Area of Science:

• Immunology
• Obstetrics
• Neonatology

Background:

• Anti-D isoimmunization typically affects Rh negative individuals.
• Rh positive or Rh weak positive pregnancies are rarely considered at risk for anti-D hemolytic disease of the fetus and newborn (HDFN).

Purpose of the Study:

• To review the clinical outcomes of anti-D isoimmunization in Rh positive or Rh weak positive women.
• To assess the incidence and severity of HDFN in this unique patient population.

Main Methods:

• Retrospective review of The Ohio State University Medical Center Fetal Therapy Program Database.
• Analysis of pregnancies affected by anti-D between 1994 and 2004.

Main Results:

• Five pregnancies (0.47%) in four Rh positive or Rh weak positive women were identified with anti-D isoimmunization.
• All affected newborns were Rh positive and did not present with anemia, require transfusion, or need treatment for jaundice.
• All newborns were delivered at term and discharged home in good condition.

Conclusions:

• Anti-D HDFN is a rare complication in Rh positive or Rh weak positive pregnancies.
• Clinical HDFN in this population appears to be mild, despite the theoretical risk of severe disease.
• Continued monitoring of Rh positive or Rh weak positive patients with anti-D isoimmunization is recommended to detect potentially significant HDFN.