Embryo selection versus natural selection: how do outcomes of comprehensive chromosome screening of blastocysts compare with the analysis of products of conception from early pregnancy loss (dilation and curettage) among an assisted reproductive technology population?

Abstract

This review provides an analysis of the most commonly identified NCAs after PGS and in first-trimester D&C samples in an infertile population utilizing ART. Although monosomies comprised >50% of all cytogenetic anomalies identified after PGS, there were very few identified in the post-D&C samples. This suggests that although monosomies occur frequently in the IVF population, they commonly do not implant. Despite this difference, this study demonstrated that the specific NCAs observed after PGS analysis and D&C were comparable.

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

“…Most common viable autosomal trisomies (chromosomes 13, 18, 21) comprised 33.4% of all autosomal trisomies detected in POCs. As previously reported [2,23], trisomy of chromosome 11 was not observed in the studied group, though it has been rarely described in some studies [20,21]. Rarity of chromosome 11 trisomy in POCs can be explained by both low frequency of chromosome 11 meiotic non-disjunction when compared to chromosomes from other groups [32] and possible early termination of pregnancies with such trisomies due to severe genetic imbalance caused by high gene density of chromosome 11 [33].…”

“…Other most common trisomies in POCs included trisomies of chromosomes 21, 22, 13, 15, and 18 (incidence is reflected by the order). Most of these are described as the most frequent both in preimplantation embryos at blastocyst stage and POCs [21,30,31]. Most common viable autosomal trisomies (chromosomes 13, 18, 21) comprised 33.4% of all autosomal trisomies detected in POCs.…”

Do specific ultrasonography features identified at the time of early pregnancy loss predict fetal chromosomal abnormality? – A systematic review and meta-analysis

“…It is known that deletion of certain region of the genome usually causes more severe outcomes that duplication 33 . Therefore, monosomy is often more detrimental than trisomy, which could cause the embryo demise at the first few days after fertilization 34 . Second, chromosome 1 aneuploidies were rarely identified in EPL.…”

Ovarian stimulation for preimplantation genetic testing

“…Traditionally, the goal of COS with exogenous gonadotropins has been to maximize oocyte yield in an effort to overcome the high rate of gamete and embryo attrition (Pellestor et al 2006, Rodriguez-Purata et al 2015. Nevertheless, the objective of COS in patients undergoing PGT has been inherently adapted.…”