Embryo fragmentation is a phenomenon that takes place in most embryos and its origin is not entirely clear. Some studies would seem to suggest that the fragments come from cell remains that have no nucleus or that they are the result of the decomposition of one or more cells from the embryo itself. The oocyte plays the most important role in fragmentation. Poor oocyte quality can lead to embryos that are highly fragmented. Embryo quality is determined by several characteristics such as the number of cells, their size or if the cell interior has an abnormality of any kind such as granularity or vacuolisation. However, one of the factors that has most impact on embryo quality is the extent of fragmentation. Based on the amount, in percentage, of space that it occupies, fragmentation is categorised into 4 types or degrees. […]
Having a sufficient number of mature egg cells is one of the key steps to obtaining excellent results in a cycle of in vitro fertilisation (IVF). In order to achieve this, the ovaries need to be stimulated and, contrary to what happens during a natural cycle, the ovaries need to simultaneously mature an appropriate number of eggs.
The most commonly used stimulation protocols are based on the use of doses of follicle-stimulating hormone (FSH). These may or may not be administered along with other drugs and vary between 150 and 300 IU/day. The response will be somewhere between 7 and 15 follicles. […]
Embryo implantation is the process in which the human embryo adheres to the endometrium, where it continues developing. The first step of this process begins with the dialogue between the embryonic and maternal cells. […]