Treatment of fetal anemia in Rh isoimmunized pregnancies with intrauterine fetal blood transfusion

Abstract

Introduction: Despite the availability of prophylactic rhesus immune globulin, hemolytic disease of the newborn and fetal death (hydrops fetalis) due to rhesus alloimmunization, is still a major contributor to perinatal morbidity and mortality in India. Pregnancy outcome after fetal therapy with ultrasound guided intrauterine transfusion (IUT) for fetal anemia was studied. Methods: A prospective cohort study of 99 Rh isoimmunized pregnancies, Indirect Coomb’s test Positive (ICT > 1:16) was conducted from July 2002 to June 2007. Intensive fetal monitoring by sériai ultrasound and middle cerebral artery peak systolic velocity using Color Doppler was performed to detect fetal anemia. When necessary, invasive testing with cordocentesis for Hb, PCV was per-formed if pregnancy was less than 32–34 weeks gestation. If PCV was < 30, or there was fetal hydrops, Ultrasound guided intrauterine transfusion was carried out by the intravascular (IVT) or the intraperitoneal (IPT) routes. Primary outcome variables were fetal survival in relation to gestational age and procedure related factors. Result: Of 99 pregnancies, 43 cases (25 — hydropic, 18-nonhydropic fetuses) required 135 intrauterine blood transfusions. The rest 56 pregnancies were managed conservatively and did not need IUT. IUTs were performed when indicated starting from 16 weeks (IPT) and 21 weeks (IVT) of gestation by the intraperitoneal / intravascular routes respectively. Pre-transfusion Hb ranged from 3g% to 8g%. The amount of blood transfused varied from 10 ml to > 110 ml depending on the period of gestation and degree of fetal anemia. The number of transfusions per pregnancy was 1–7, at intervals of 1–4 weeks, till delivery at 28 to 36 weeks of gestation. Survival of hydropic babies (88%) was almost similar to those without hydrops (83.3%) Prognosis was slightly better in Rh isoimmunized pregnancies not requiring IUT (94%) compared to fetuses receiving transfusions (85.6%). Conclusion: Intrauterine fetal blood transfusion was found to be the only life saving therapy, and very effective in the management of preterm Rh isoimmunized pregnancies. Results are comparable with the best centers in the world, hence early referral to specialized centers with expertise of specialized intensive fetal monitoring for early diagnosis of fetal anemia, and of intrauterine fetal blood transfusion are important for optimal perinatal outcome.