Hydrops fetalis associated with fetal hemoglobin H-Pakse disease

Introduction: Hemoglobin H-Pakse (Hb H-PS) disease is a variant of non-deletional Hb H disease associated with various degrees of anemia. The disorder is rare but commonly seen in Southeast Asia. However, the prenatal course of Hb H-PS disease has never been published. The objective of this report is to describe prenatal diagnosis and management of Hb H-PS disease, which is theoretically much more critical in fetal life than adult life. 
Case presentation: The prenatal courses of two fetuses affected by Hb H-PS were comprehensively explored. Both of them showed sonographic signs of fetal anemia at 19–20 weeks of gestation (increased cardiac size and increase middle cerebral artery-peak systolic velocity, MCA-PSV). On follow-up scans, both revealed frank hydropic signs at 22–24 weeks. One fetus died at 24 weeks, shortly before the scheduled intrauterine blood transfusion (IUT). The other one underwent IUT at 22 weeks, leading to completely reversed hydropic signs, which resulted in successful outcomes that ended with the delivery of a healthy baby at term. The fetus needed only one IUT and the course of anemic status improved in late pregnancy. IUT in this case was possibly beneficial to adult life. 
Conclusion: Fetuses with Hb H-PS may be associated with hydrops fetalis, usually occurring at mid-pregnancy. The hydrops tends to improve in late gestation. If they can pass through this most critical period in utero without anemic insults in developing organs, good long-term prognosis can be expected. This successful prenatal diagnosis and intrauterine treatment may encourage care providers to pay more attention to fetal Hb H-PS disease, to prevent anemic hypoxia in developing organs and adult diseases of fetal origin.