Flow cytometric studies in spontaneous abortions. Applications in the medico-legal practice

In the medico-legal practice differential diagnosis between spontaneous and non-spontaneous abortion is important because causes of pregnancy wastage are often obscure and, moreover, spontaneous abortion is more common than accidental or voluntary. In all the cases in which the cause of abortion is not otherwise detectable and especially in cases of discovery of fetal adnexa, it is necessary to investigate genetic causes. Recently, DNA flow cytometric analysis has been applied in determining the genetic causes of spontaneous abortions. Among karyotypic abnormalities, flow cytometric analysis on paraffin embedded material can detect only polyploidies (triploidy and tetraploidy). Trisomies, monosomies and structural anomalies cannot be detected. In our study we tried to establish whether flow cytometry could be useful in determining the genetic cause of spontaneous abortions, in the lack of any other detectable cause. Histologic examination and flow cytometric analysis were performed on a series of 395 consecutive spontaneous abortions. Histologic examination allowed the detection of a molar pattern in about 9% of cases. DNA flow cytometric analysis showed diploidy in 346 (87.59%) cases, triploidy in 37 (9.36%) cases and tetraploidy in 12 (3.03%) cases. Combined microscopic and flow cytometric analysis revealed abnormalities in 17.5% of cases. A non-diploid pattern is more frequent in molar cases (P less than 0.001). Flow cytometry seems to be interesting in forensic pathology, as it allows the detection of some frequent genetic abnormalities in dead tissues and cells, when other techniques are no longer practicable.