Analyses of 95 first-trimester spontaneous abortions by chorionic villus sampling and karyotype.

PURPOSE: Our purpose was to determine the incidence of chromosomal aneuploidy in first-trimester pregnancy losses using chorionic villus sampling (CVS).

STUDY DESIGN: All patients presenting for CVS with no fetal cardiac activity were offered CVS.

RESULTS: Cytogenetic results were completed in 95 of 96 cases (99%). Eighty-three percent of the karyotypes were aneuploid. The 16 euploid fetuses had no excess of females.

CONCLUSION: CVS is the most reliable method of determining the karyotype of spontaneously aborted fetuses. The incidence of aneuploidy is much greater than in previous reports that analyzed passed products of conception. CVS should be offered to women who present with first-trimester spontaneous abortions.