Tissue sampling technique affects accuracy of karyotype from missed abortions.

PURPOSE: To determine if careful specimen selection and washing of tissue from first trimester missed abortion products of conception specimens increases the sensitivity of routine cytogenetics in detecting aneuploidy.

METHODS

Retrospective review of cytogenetics results from tissue from dilation and curettage for missed abortion in a university fertility practice between 1998 and 2001. A technique of careful selection and washing of the specimen was implemented in July 1999. Results from before (n = 15) and after (n = 41) this change were compared. Cytogenetics reports from other physicians using the same laboratory were used for comparison (n = 59).

RESULTS

The percentage of 46XX results was significantly decreased in the test group when compared to historical and community controls: 29% vs. 73% and 56% respectively. The percentage of aneuploid results was significantly higher in the test group at 61% vs. 7% and 36% in the historical and community controls respectively.

CONCLUSION

Thorough separation and cleaning of villi prior to sending missed abortion specimens significantly increases sensitivity of conventional cytogenetics for detecting aneuploidy by decreasing maternal contamination.