HISTOLOGICAL EXAMINATION OF 1ST TRIMESTER SPONTANEOUS-ABORTIONS - THE IMPACT OF MATERNO-EMBRYONIC INTERFACE FEATURES

Cytogenetic findings and placental histological features of 319 consecutive first trimester spontaneous abortions were retrospectively investigated. Correlation of cell culture results and microscopic examination based on conventional villous histological criteria showed an overall sensitivity of 45.1% for histology in detecting chromosomal anomalies. Discrepant cases, i.e. normal histology with unequivocal chromosomal anomaly and abnormal histological features suggesting a chromosomal anomaly according to the classical criteria but with a normal karyotype, were reviewed by two independent observers using extended histological criteria including features of the materno-embryonic interface. There was a significant (P < 0.001) increase of the sensitivity of histology to 66.4% for both observers after the second histological examination. Macerated specimens or incomplete specimens made of chorion laeve or maternal decidua only are difficult to evaluate, and represent the main cause of discrepancy between cytogenetics and morphology. The results of this study indicate that the sensitivity and specificity of microscopic examination in cases of early spontaneous abortion may be improved by adding features of the materno-embryonic interface to classical villous histological criteria.