The influence of foetal haemoglobin on the frequency of vaso-occlusive crisis in sickle cell anaemia patients.

Objective: Several biological and environmental factors are presumed to account for the morbidity pattern in patients with sickle cell anaemia. Foetal haemoglobin is one of the biological factors thought to decrease morbidity in these patients. We studied the relationship between the foetal haemoglobin levels and vaso-occlusive crisis (VOC) as a measure of the morbidity pattern in this category of patients.

Results: The mean foetal haemoglobin level was 6.4+0.40% (SEM). Vaso-occlusive crisis was more common at lower levels of foetal haemoglobin particularly when lower than 12% (P=0.01). There was a negative correlation between foetal haemoglobin and vaso-occlusive crisis (r=0.561). These variables were also associated in linear regression and both showed statistical significance (p=0.001).

Conclusion: We conclude that higher levels of foetal haemoglobin positively influence the occurrence of vaso-occlusive crisis in sickle cell anaemia patients.