Hypermodal cells, hypomodal cells, and repetitive abortions.

The frequency of neither hypermodal cells (2N = 47) nor hypomodal cells (2N = 45) differed between lymphocytes of individuals experiencing repetitive spontaneous abortions (N = 429) and controls (N = 90). The same conclusion held when data were analyzed according to chromosome involved (sex chromosome, autosome) or other variables (e.g., prior reproductive outcome). A study of this relatively large sample failed to confirm findings of smaller and sometimes uncontrolled studies. Hypermodal cells do not necessarily serve as a clue to meiotic instability and in turn probably do not identify couples at risk for recurrent aneuploidy.