The importance of systematic haemoglobin screening in subjects at high risk of haemoglobinopathy

It is not wise to wait until fetal death is discovered to investigate haemoglobin abnormalities in high-risk parents. Systematic screening of such couples before conception would make it possible to provide relevant genetic advice. In a recent case, the discovery of a hydrops fetalis after 21 weeks of amenorrhoea led us to conduct a fetal karyotype study. Fetal blood was collected. A Kleihauer test and haemoglobin electrophoresis were performed to ensure that there was no maternal blood contamination. Haemoglobin electrophoresis unexpectedly revealed total absence of HbF ( alpha sub(2) gamma sub(2)) and HbA ( alpha sub(2) beta sub(2)), a high proportion (77 percent) of Hb Bart's ( gamma sub(4)), and some Hb Portland ( zeta sub(2) gamma sub(2)) (15 percent) and HbH ( beta sub(4)) (8 percent).