Developmental origin of chorionic villus cultures from spontaneous abortion and chorionic villus sampling.

OBJECTIVE

Chorionic villus cultures from spontaneous abortions and chorionic villus sampling (CVS) are routinely used for clinical cytogenetic analysis. Although these cultures are assumed to represent the chorionic villus mesenchymal core, and therefore the inner cell mass (ICM) of the blastocyst, immunochemical studies using a true trophoblast-specific marker to definitively rule out trophoblast contamination have not been done. Therefore, we used cytokeratin-7 (CK7), a trophoblast-specific marker, to assess the developmental origin of these chorionic villus cultures.

METHODS

We assessed chorionic villus cultures from CVS and spontaneous abortions for CK7 immunostaining (n = 20).

RESULTS

Cultures from both CVS and spontaneous abortions showed little or no CK7 staining (≤ 1%).

CONCLUSION

Chorionic villus cultures from CVS and spontaneous abortions exhibit little or no trophoblast contamination. They are therefore representative of the villus mesenchymal core and ultimately originate from the ICM of the blastocyst.