Size of Y chromosome not associated with abortion risk.

The average length of the Y chromosome in men whose wives had multiple fetal loss was 1.046 +/- 0.106, which is not significantly different from the average length in controls (1.068 +/- 0.096). Therefore, it is concluded that there is no evidence for an association of the size of the Y chromosome with an increased risk of abortions as previously suggested. Furthermore, the authors suggest that the definition of a large Y be revised, as the majority of normal males have a Y/F index of more than 1.0, so a Y/F ratio of greater than 1.0 should not be considered a long Y chromosome.