SUMMARY THE CENTROMERIC INDEX OF Y CHROMOSOME IN COUPLES WITH RECURRENT SPONTANEOUS ABORTION Centromeric index Y chromosome has been determined in 25 male partners of couples without history of abortion and 25 male partners of couples giving history of abortion with unknown etiology. While the ma en values of centromeric index of Y chromosome for the control group were 27.2111.85 those for the .spontaneous abortion group were found to be 22.2312.61. This difference between those two groups had a statistical importance (p