Chromosome analysis of 303 pregnancy losses in Mexico

Chromosomal abnormalities are present in 50 to 60% of miscarriages and in 6 to 19% of stillbirths. Although microarrays are preferred for studying chromosomal abnormalities, many hospitals cannot offer this methodology.

To present the results of the cytogenetic analysis of 303 products of conception (POC), which included 184 miscarriages, 49 stillbirths and 17 cases of undefined age.

Karyotyping, fluorescence in situ hybridization, short tandem repeats and microarrays were used, depending on the type of loss and available sample.

In 29 POCs we found maternal tissue and were eliminated from the analyses. Informative results were obtained in 250 (91.2 %)/274 cases; the karyotyping success rate was 80.7%; that of single nucleotide polymorphism microarrays, 94.5%; and that of fluorescence in situ hybridization and short tandem repeat, 100%. Cytogenetic abnormalities were observed in 57.6% of miscarriages and in 24.5% of stillbirths; 94% of total anomalies were numerical and 6% were submicroscopic.

Karyotyping with simultaneous short tandem repeat study to rule out contamination of maternal cells is effective for studying miscarriages; in stillbirths, microarrays are recommended.