Comparative genomic hybridization for cytogenetic evaluation of stillbirth.

OBJECTIVE: To ascertain the feasibility and reliability of comparative genomic hybridization for cytogenetic evaluation of macerated stillbirths. MATERIALS: We examined ten stillborn fetuses above 15 weeks' gestation whose karyotypes were unknown because of tissue culture failure. Sixteen fetuses that were successfully karyotyped using prenatal or postnatal tissues were also examined as controls, including five pregnancy terminations with autosomal aneuploidy, one with sex chromosome aneuploidy, one with a chromosomal deletion; five macerated fetuses with normal karyotypes, three with autosomal aneuploidy, and one with sex chromosome aneuploidy and discrepancy between chorionic villi and fetus.
RESULTS: All comparative genomic hybridization analyses in fresh and macerated tissues were successful except for one. All normal karyotypes and aneuploidies were confirmed. Comparative genomic hybridization failed in one fetus with a deletion of the short arm of chromosome 18. In the stillborn fetuses without known karyotypes, one aberrant profile was found; however, the results were not confirmed with interphase fluorescence in situ hybridization. In one fetus triploidy was diagnosed with DNA flow cytometry.
CONCLUSION: Comparative genomic hybridization is a valuable backup technique for aneuploidy screening in tissues from macerated stillborn fetuses when tissue culture fails. Gains or losses can subsequently be confirmed by fluorescence in situ hybridization, using DNA probes that focus on specific loci of a chromosome.