Value of enzymatic examination of blood stains in determination of the period of gestation

ABSTRACT

The objective of this work is to establish the diagnostic efficiency of the determination of the ratio between heat-stable [H-S] and total [T] alkaline phosphatase activities in dry blood stains on an absorbent surface [Cotton Cloth] in cases of pregnancy. Blood samples were obtained from healthy adult males and nonpregnant females [Control group, 10 cases, 5 males and 5 females], pregnant females at different stages of pregnancy [30 samples, 10 in each trimester] and patients with elevated values of alkaline phosphatase [obstructive jaundice, 9 samples]. The blood stains were left at room temperature for different periods up to 6 months. The values of [H-S] and [T] alkaline phosphatase were measured in the serum of the control group and the blood stains of all groups and then we determined the ratio between them [H-S/T]. We found that the values of [H-S] and [T] alkaline phosphatase in the serum were higher than those in the blood stains of the control group but the ratio was the same. There was a statistically significant progressive rise in the ratios between [H-S] and [T] alkaline phosphatase in blood stains of pregnant females at different trimesters and a significant decreased ratio in the blood-stains of the group of obstructive jaundice. The same results were obtained with aged blood stains up to 6 months