Homozygous Deletion Alpha-Thalassemia and Hereditary Persistence of Fetal Hemoglobin, Two Genetic Factors Predictive the Reduction of Morbidity and Mortality During Pregnancy in Sickle Cell Patients. A Report from the Democratic Republic of Congo

OBJECTIVE: to determine the beneficial role of Fetal Hemoglobin (FHb) and alpha-thal on fetal and maternal morbidity during pregnancy in sickle cell patients. STUDY SITE: the study was conducted at the sickle cell center of Kinshasa between 2008 and 2018 SETTING AND STUDY POPULATION: this is a documentary and analytical study that included 980 deliveries of homozygous sickle cell patients. METHODS: the diagnosis of SCD and the quantification of FHb were performed with the capillary electrophoresis technique. The molecular test confirmed the diagnosis of SCD. The diagnosis of alpha-thal was made with the multiplex ligation-dependent probe amplification (MLPA) technique. Sickle cell pregnancies were followed according to the protocol of care in force in the University of Kinshasa Hospital service. The variables of interest were: hematological variables, sickle cell crises during pregnancy, maternal and fetal complications. STATISTICS: statistical analyses were performed with SPSS 20.0 software. Means and standard deviations were compared with the Student’s t and ANOVA tests. The value of p <0.05 was considered the significance level. RESULTS: the Hb-SS / alpha-thal and HbSS / HPFH genotypes were observed in 101 and 121 women, respectively. Otherwise, 758 women had HbSS genotype. The morbidity related to sickle cell complications in the mother and fetus were less frequent in the Hb-SS / alpha-thal and HbSS / HPFH groups than in HB-SS group. The differences were statistically significant. CONCLUSION: this study showed a significant protective effect of alpha-thal and HPFH during pregnancy in sickle-cell pregnant women.