An international registry of survivors with Hb Bart's hydrops fetalis syndrome

Abstract

Hemoglobin (Hb) Bart's hydrops fetalis syndrome (BHFS) resulting from α-thalassemia is considered a universally fatal disorder. However, over the last 3 decades, improvements in intrauterine interventions and perinatal intensive care have resulted in increasing numbers of BHFS survivors. We have initiated an international registry containing information on 69 patients, of which 31 are previously unpublished. In this perspective, we analyze the available clinical information to document the natural history of BHFS. In the future, once we have accrued sufficient cases, we aim to build on this study and provide information to allow counseling of at-risk couples. To date, 39 patients have survived beyond the age of 5 years, 18 of whom are now older than 10 years. Based on the available cases, we find evidence to suggest that intrauterine therapy provides benefits during the perinatal and neonatal period; however, it may not provide additional benefits to long-term growth and neurodevelopmental outcomes. Growth retardation is a major adverse long-term outcome among BHFS patients with ∼40% being severely affected in terms of weight and ∼50% in terms of height. There is also an increased risk of neurodevelopmental delay as we find 20% (11/55) of BHFS survivors suffer from a serious delay of ≥6 months. Most patients in the registry require lifelong transfusion and often have associated congenital abnormalities and comorbidities. This perspective is a first step in gathering information to allow provision of informed counseling on the predicted outcomes of affected babies.

Outcomes and morbidities of patients who survive haemoglobin Bart’s hydrops fetalis syndrome: 20-year retrospective review

“…Two-thirds of our patient cohort showed growth retardation, global developmental delay, and/or long-term residual neurological deficits. These findings are comparable to those from an international case series 29 and an overseas case report. 11 Lifelong hypertransfusions every 4 to 6 weeks and iron chelation are expected for BHFS survivors.…”

“…Approximately two-thirds of all cases used IUT 29 (41/69; 59%), which is similar to the proportion of local cases (5/9; 56%). Globally 29 and locally, most infants were delivered prematurely (respectively, 47/66; 71% and 7/9; 78%).…”

“…Approximately two-thirds of all cases used IUT 29 (41/69; 59%), which is similar to the proportion of local cases (5/9; 56%). Globally 29 and locally, most infants were delivered prematurely (respectively, 47/66; 71% and 7/9; 78%). Approximately one-fifth (14/69) of all BHFS survivors underwent stem-cell transplantation, 29 again similar to our local situation (2/9).…”

“…Globally, 69 survivors are reported in the international BHFS registry 29 with our local cohort (n = 9) contributing about one-seventh of cases. Approximately two-thirds of all cases used IUT 29 (41/69; 59%), which is similar to the proportion of local cases (5/9; 56%).…”

“…Globally 29 and locally, most infants were delivered prematurely (respectively, 47/66; 71% and 7/9; 78%). Approximately one-fifth (14/69) of all BHFS survivors underwent stem-cell transplantation, 29 again similar to our local situation (2/9). Congenital anomalies were present in all of the local patients, compared with two-thirds (37/55; 64%) worldwide, 29 although urogenital and limb defects remained the most common.…”