RESUMEN
Molecular analysis of serum and plasma DNA during human pregnancy has led to the discovery that maternal blood contains fetal DNA. This valuable source of fetal DNA opens up new possibilities for noninvasive detection of fetal sex or prenatal diagnosis of various sex linked diseases. DNA was extracted from each serum and plasma sample of 25 cases of normal pregnancy, ranging from 10-16 weeks gestation to detect the Y chromosome specific sequences DYS14 in maternal blood, polymerase chain reaction [PCR] were carried out for each DNA extract. The result revealed that 13 out of 25 pregnant women had a Y chromosome specific sequence in their serum samples and 11 of them had Y chromosome specific sequence in their plasma, when doing pelvic U/S at 21 weeks gestation, all 13 cases were diagnosed having male fetus and this was confirmed after delivery