Objective To explore reliable evidences for thalassemic prenatal screening by investigating the corresponding relationship of hematologic indexes and thalassemic genotypes in pregnant women.  Methods Generally hematologic detection for thalassemia was carried out on the peripheral venous blood samples of all prenatal checked-up expectant mother. Those suspectable thalassemic sufferers were further identified by gene diagnosis

and then the husband was detected when his wife was thalassemic patient. For the couple with same thalassemia genetype

prenatal diagnosis was conducted. Genes of suspectable β-thalassemic couples were sequenced

and mutational hot spots of β-globin were studied by BLAST to explore unknown mutation.  Results Totally 115 pregnant wom

en were suspectable thalassemia

and 73 cases among them were final diagnosed. There was 1 couple of simultaneous α-thalassemia

and 3 couples of βthalassemia. Prenatal diagnosis found 3 fetuses with serious thalassemia. Hb

MCV

RBC

RDW and HbA

2

had statistical significance between α

β

α/β and β/β (P0.01). There were about 2 to 5 SNP in the suspectable β-thalassemia.  Conclusion Thalassemia is quite common in Chongqing. Red cell parameters and quantitative hemoglobin electrophoresis are important in all screening indexes. Gap-PCR

PCR-RDB and genetic sequences analysis should be used to diagnose exactly so as to prevent thalassemic birth defect.