The chromosome analysis of the miscarriage tissue. Miscarried embryo/fetal crown rump length (CRL) measurement: A practical use

Objective\r\nTo investigate whether miscarried embryo/fetal crown rump length (CRL) measurement\r\nmay yield a practical application for predicting a conclusive result at the cytogenetic analysis\r\nof miscarriage tissue. Our study might help in improving the cytogenetic method, the results\r\nof which may be affected by maternal cell contamination (MCC). In particular, we aimed at\r\nestablishing whether the miscarried embryo/fetal CRL measurement shows accuracy in predicting\r\nthe possibility of MCC and the scan cut-off value useful to this purpose and, as a\r\nresult, suggest a multi-step procedure for the genetic ascertainment.\r\nMethods\r\nWomen experiencing at least two miscarriages of less than 20 weeks size at the Pregnancy\r\nLoss Unit at Fondazione Policlinico A. Gemelli underwent a scan before surgery. The CRL\r\nvalue was recorded. After the dilatation and courettage (D&C) procedure, miscarriage tissue\r\nwas processed through the proposed multi-step procedure before performing oligo-nucleotide-\r\nbased and SNP (single nucleotide polymorphisms)-based comparative genomic hybridization\r\n(CGH+SNP) microarray analysis.\r\nResults\r\n63 women and 63 miscarriages met the criteria. By using the Receiving Operator Characteristic\r\n(ROC) curves, CRL showed an AUC of 0.816 (95%CI:0.703±0.928,p<0.001). A\r\nCRL24.5 mm cut-off value showed a higher positive likelihood ratio (5.27) but, conversely,\r\na higher negative likelihood ratio (0.64) in predicting the possibility of MCC. Microarray analysis\r\nwas successful in the totality of cases in which the embryo/fetal origin of miscarriage tissues\r\nwas proven.