Prevalence and spectrum of chromosome abnormalities among spontaneous and induced early reproductive losses: 2020 miscarriages and 1572 medical abortions

Abstract

This article presents the data of a comparative analysis of 9 large studies of non-developing pregnancies (NB) karyotype, published after 2000, as well as results of our own study of NB and medical abortion (MA), performed in the first trimester of pregnancy. Objective of the study: to assess the prevalence and structure of chromosomal abnormalities (CA) among spontaneous and induced reproductive losses in the first trimester of pregnancy. Materials and methods. From 1997 to 2019 karyotyping of concept products was carried out for NB (n = 2020) in terms of 5–13 weeks, obtained from women from 7 regions of the South-Eastern and Central regions of Ukraine, and MA (n = 1572) performed in the first trimester of pregnancy. Results. The efficiency of NB material karyotyping was 94%. Chromosomal pathology (CP) was 56.5% in NB material and 5.4% in MA material; autosomal trisomies – 51% of all CP among NB and 48.2% of all CP among MA; triploidy – 17.8% and 15.3% in the NB and MA groups, respectively; tetraploidy – 8.67% and 12.9%; monosomy X – 12.9% and 10.6%; restructuring – 5.5% and 10.6%; multiple trisomies – 3.2% and 3.5%, that is consistent with the data of other studies. In this study authors noted a significant predominance of 15, 16, 22 chromosomes trisomy over 13, 18, 21 chromosomes trisomy, as well as a large proportion of diandroid triploidies in comparison with other studies. Differences in the CA structure in anembryonic and NB with an embryo presence were established – multiple predominance of tetraploidies and structural rearrangements in anembryony and 15 chromosome trisomy, as well as X monosomy in an embryo presence. An association of mother's young age with a higher incidence of triploidies among NB was noted. Conclusions. The absolute majority of CA among NB and MA occurs sporadically, with exception of some structural rearrangements (robertsonian and reciprocal translocations). Our outcome analysis showed that standard karyotyping is still the first-line choice for examining the products of the concept of early pregnancy losses.

Keywords

• early pregnancy losses
• spontaneous abortion
• medical abortion
• anembryony
• karyotype
• chromosome abnormalities