Cytogenetic testing of pregnancy loss tissue: a meta-analysis

Many clinics offer routine genetic testing of pregnancy loss tissue. This review presents a comprehensive literature search and meta-analysis on chromosomal abnormality rates of pregnancy loss tissue from women with a single or recurrent pregnancy loss. A total of 55 studies published since 2000 were included, analysed on the prevalence of test failure rates, abnormality detection rates and percentages of trisomy, monosomy X, structural abnormalities and other clinically (ir)relevant abnormalities detected by conventional karyotyping, array-comparative genomic hybridization (aCGH), single nucleotide polymorphism (SNP) array, fluorescence in-situ hybridization (FISH) and multiplex ligation-dependent probe amplification (MLPA). The detected prevalence of chromosomal abnormalities was 48% (95% confidence interval [CI] 39-57) using aCGH, 38% (95% CI 28-49) with FISH, 25% (95% CI 12-42) using MLPA, 60% (95% CI 58-63) using SNP array and 47% (95% CI 43-51) with conventional karyotyping. The percentage of detected abnormalities did not differ between women that suffered sporadic (46%; 95% CI 39-53) or recurrent (46%; 95% CI 39-52) pregnancy loss. In view of the high prevalence of chromosomal abnormalities in pregnancy loss tissue, and the low chance of recurrence of the same chromosomal aberration, it was concluded that detection of specific chromosomal abnormalities in pregnancy loss tissue has no clinical benefit. Therefore, routine testing of pregnancy loss tissue for chromosomal abnormalities is not recommended.