Chromosomal abnormalities in products of conception of first-trimester miscarriages detected by conventional cytogenetic analysis: a review of 1000 cases

The purpose of this study is to perform a retrospective analysis of types and frequencies of chromosomal abnormalities detected by conventional cytogenetic studies in first-trimester miscarriages after spontaneous conception and IVF. Standard cytogenetic analysis of GTG-banded chromosomes obtained from products of conception (POCs): semi-direct and short-term cultured chorionic villi or long-term cultured fetal mesodermal cells. 50.1% of first-trimester miscarriages in the studied group had chromosomal abnormalities: 59.7% of trisomies, 22% of poliploidies, 7.5% of monosomies, 7% of unbalanced structural abnormalities, and 3.8% of multiple aneuploidies. An increase in the frequency of chromosomally abnormal miscarriages was observed in the group of women above 40 when compared to groups of women under 35 (P < 0.05). No difference in frequencies and types of chromosomal abnormalities in POCs of miscarriages after ICSI and spontaneous conception was observed. Approximately, 50% of first-trimester miscarriages have chromosomal abnormalities which can be detected by conventional cytogenetic analysis. The presence of chromosomal abnormality may explain the cause of miscarriage, improving the reproductive counseling and planning.