1. New alternatives for management of isoimmunization Nuevas alternativas en el manejo de la isoinmunización Leonardo Pereira MD Assistant Professor Maternal-Fetal Medicine Oregon Health & Science University

2. Causes of fetal anemia Red cell alloimmunization hemolytic disease of the newborn (EF) direct bone marrow suppression Viral infections parvovirus B19 toxoplasmosis coxsackie cytomegalovirus Hemoglobinopathies alpha-thalassemia Genetic Disorders Fanconi syndrome TAR syndrome Aase syndrome Twin to Twin Transfusion

3. Liley Curve ΔOD450 Timeline: hemolytic disease of the newborn 1940 195019601970 1980 1990 2000 Discovery of Rh factor Landsteiner & Weiner Postnatal Exchange Transfusions Prevention α-RhD Ig Queenan Modification ΔOD450 Maternal serum antibody titers MCA Doppler Noninvasive detection HDN described Fetal RhD Maternal Plasma Amniotic fluid bilirubin measurement

4. Fetal antigenic determination Amniocentesis, CVS, cordocentesis samples can be used to determine fetal antigen status by DNA typing 100% accuracy in 390 samples Bennett et al. 1993 Molecular analysis of maternal plasma: fetal DNA for RhD 100% accuracy in 45 fetuses second/third trimester Lo et al. N Engl J Med 1998;339:1734-8. PCR from cell free DNA in maternal serum 100% accuracy in 137 fetuses (including 21 female fetuses) Finning et al. Transfusion 2002;42:1079-85. Possible utility in embryo selection for sensitized mothers

5. Mari et al. N Eng J Med 2000

6. MCA-PSV

7. Fetal Hemoglobin (g/dl) by Gestational Age Weeks Gestation 1812.310.68.96.9 5.8 2012.911.19.37.2 6.1 2213.411.69.77.5 6.4 2413.912.010.17.8 6.6 2614.312.310.38.0 6.8 2814.612.610.68.2 6.9 3014.812.810.88.3 7.1 3215.213.110.98.5 7.2 3415.413.311.28.6 7.3 3615.613.511.38.7 7.4 38 15.8 13.611.48.9 7.5 4016.013.811.69.0 7.6 mildmoderate severe anemiaanemia anemia Mari, et al. N Eng J Med 2000. Multiples of the Median 1.161.000.840.65 0.55 Hgb Values

8. Initial prospective study of 16 fetuses: 14 anti-D, 2 anti-c Mari et al. Ultrasound Obstet Gynecol 1995;5:400-5. Since then several prospective and retrospective studies: over 200 additional cases Rbc alloimmunization and parvovirus B19 Scott et al. Prenat Diagn 1998;18:1143-8. Teixeira et al. Ultrasound Obstet Gynecol 2000;15:205-8. Delle Chiaie et al. Ultrasound Obstet Gynecol 2001;18:232-6. Mari et al. N Eng J Med 2000;342:9-14. Zimmermann et al. Br J Obstet Gynecol 2002;109:746-52. Mari et al. Ultrasound Obstet Gynecol 2002;99:589-93. Current evidence supporting MCA-PSV Doppler velocimetry

9. Sensitivity 87-90% Specificity88-100% PPV53-74% NPV98-100% Data combined from 7 studies: rbc alloimmunization and parvovirus B19

10. 4 Comparative Studies N = 28 Nishie EN, et al. Am J Obstet Gynecol 2003;188:214-9. N = 28 Pereira L et al. Am J Obstet Gynecol 2003;189:1002-6. N = 38 Bullock R, et al. Ultrasound Obstet Gynecol 2005;25:331-4. N = 165 Oepkes D, et al. N Engl J Med 2006;355:156-64. Prediction of fetal anemia by MCA-PSV Doppler compared to Amniocentesis

11. Conventional Management of Fetal Alloimmunization Compared to Management by Middle Cerebral Artery Peak Systolic Velocity. Purpose: To determine the predictive accuracy of MCA-PSV measurements for moderate or severe fetal anemia in erythrocyte alloimmunized pregnancies To compare management of alloimmunized pregnancies by serial MCA-PSV measurements to our conventional management Pereira L et al. Am J Obstet Gynecol 2003;189:1002-6. Prediction of fetal anemia by MCA-PSV Doppler compared to Amniocentesis

12. Distribution of Erythrocyte Antibody Specificities Antibody Specificity n = 28 D 9 Kell1 Kell and Kidd1 D and C3 D and M2 D, C, E, Kidd1 D, C, e, Kidd1 E3 c2 C and Kidd1 u1 anticoltan1 Kidd1 Duffy1

13. Maternal serum titers every 3-4 weeks Indications for amniocentesis and US critical threshold earlier if prior affected pregnancy Amniocentesis every 2-4 weeks, US every 2 weeks Indications for PUBS abnormal amniocentesis US evidence of fetal hydrops Kell sensitization Transfusion for moderate or severe anemia PUBS repeated as necessary, weekly US Conventional Management

14. Fetuses Total Procedures 24/28 (86%)49 Amniocenteses 9/28 (32%)14 PUBS Results

15. 28 CasesDiagnosis 20 non-anemic2 PUBS, 18 neonatal Hct 3 mild3 PUBS 1 moderate 1 PUBS 4 severe3 PUBS, 1 neonatal Hct Diagnosis of Anemia

16. 4 1 518 Conventional MCA-PSV PUBS NO PUBS PUBS NO PUBS MODERATE OR SEVERE ANEMIA MILD ANEMIA OR NORMAL HEMOGLOBIN 9 19 7 21 4 Anti-D 2 Anti-Kell 1 Anti-C 1 Anti-c 1 Anti-D,C, E,Kidd 5 0 221 4 Anti-D 1 Anti-D,C, e,Kidd 1 Anti-D 1 Anti-u 1 Anti-D,C, e,Kidd

17. AmniocentesisMCA-PSV Sensitivity80 (4/5) 100 (5/5) Specificity78 (18/23) 91 (21/23) PPV44 (4/9) 71 (5/7) NPV95 (18/19) 100 (21/21) FP rate 56 (5/9) 28 (2/7) FN rate 5 (1/19) 0 (0/21) RR (95%CI) 3.7 (1.5-9.0) 11.5 (3.1-43.2) Predictive Accuracy

18. Initial Study (28) Current Totals (42) Sensitivity 100 90 Specificity 91 91 PPV 71 75 NPV 100 97 FP rate 28 25 FN rate 0 14 RR (95%CI) 11.5 22.5 Predictive Accuracy

19. Current evidence Sensitivity 53-8664-100 Specificity71-7881-91 PPV44-10047-75 NPV95-9697-100 MCA-PSV Doppler Amniocentesis N =259 Cummulative ranges from 4 trials

20. 14,000 cases of alloimmunization per year in the U.S. Avoid 24,500 amniocenteses and 900 PUBS Avoid 1 pregnancy loss/preterm delivery for every 100 patients; 142 nationwide per year Avoid worsening sensitization from procedure related bleeding complications – TPH risk 2-10% following amniocentesis, 50% following PUBS Potential Benefits of Management by MCA-PSV

21. Limitations of MCA-PSV Angle of insonation - underestimate the MCA-PSV Distal MCA - underestimate the MCA-PSV Blood viscosity - decreased sensitivity after multiple transfusions (> 3) Fetal cerebral hemodynamics - anatomic lesions (severe ventriculomegaly, calcified cystic lesions, solid tumors, or vascular malformations) - accuracy of MCA-PSV not well characterized

22. Dependent on normal left ventricular cardiac output - fetal hydrops, CHD, cardiomyopathy Decreased specificity of MCA-PSV after 35 weeks gestation Multiple factors affect the MCA-PSV: fetal behavioral state, maternal medications, labor Intermittent vascular constriction - overestimate the MCA- PSV (may explain several reported cases where an elevated MCA-PSV measurement has not been reproducible) Limitations of MCA-PSV

23. Areas for Future Research Accuracy of MCA-PSV in fetuses with anemia from other etiologies MCA-PSV in clinical practice Fetuses with compromised left-sided cardiac output Fetuses with platelet or neutrophil disorders

24. Conclusion MCA-PSV accurately predicted moderate to severe fetal anemia Compared to conventional management, MCA- PSV may have a better predictive accuracy for moderate or severe anemia in alloimmunization Management by MCA-PSV may eliminate the need for amniocentesis and reduce the number of PUBS performed in alloimmunized pregnancies

25. Management protocol Identify at risk pregnancies: prior affected pregnancy, critical maternal serum titer, Kell sensitized, other suspected etiology Weekly measurements of the MCA-PSV (18-20 weeks - 35 weeks) If MCA < 1.5 MoM and steady in zone then measure every 10-14 days If MCA < 1.5 MoM and increasing in zones then follow every 2-7 days If MCA > 1.5 MoM then cordocentesis with possible transfusion or repeat in 12-18 hours If sonographic evidence of hydrops then cordocentesis with possible transfusion Revert back to “conventional management” if: > 3 intrauterine transfusions, or one of the cases mentioned previously where reliability of MCA-PSV not yet established

26. Thank you