An embryo’s ability to develop could stop for a variety of causes. The embryo might have slowed growth or decreased metabolic activity, which would cause it to degenerate. During certain phases of development, embryos can also stop developing. For numerous causes, some of which are covered below, they may not develop to the blastocyst stage.
Chromosomal defects are present in about 70% of stopped embryos. Chromosomes, which resemble rope-like structures inside your cells, house DNA, or the genetic code that gives you your individuality. The mother and father each contribute 23 chromosomes to the union of sperm and egg, giving the resultant embryo a total of 46 chromosomes.
Chromosomal mistakes can occur when chromosomes don’t unite correctly on occasion. This might entail having:
- An excessive number of chromosomes (also known as Aneuploidy);
- The presence of multiple complete sets of chromosomes (polyploidy);
- A condition known as mosaicism, which combines both normal and aberrant chromosomal counts.
Additionally, as the embryo’s cells divide and replicate, chromosomal abnormalities may appear. During the early stages of development, sometimes referred to as the cleavage stage, when an embryo splits incorrectly, this can cause an aberrant distribution of chromosomes across cells and result in embryo arrest. Embryo arrest can also result from damaged or aberrant DNA replication in embryonic cells.
Preimplantation genetic testing (PGT) may be advised since some chromosomal defects do not prevent the embryo from developing.