What to choose between fresh, frozen and blastocyst embryos? The right one for you is the best!

Blastocyst culture is another choice that many IVF families face after egg retrieval. There are various myths about blastocysts circulating among many IVF people, who believe that blastocysts are the best embryos, and that they should be taken to blastocyst culture as long as there are embryos available.

　　Firstly, let’s understand about cleavage stage embryos, blastocysts and frozen embryos
　　Typically, when undergoing IVF to assist conception, we use ovulation stimulating drugs to promote the growth of a group of follicles, and when the eggs mature, they are removed through egg retrieval and combined with sperm in a petri dish to form an embryo. The embryo continues to develop outside of the body and is classified as a cleavage stage embryo or blastocyst depending on the number of days it has been developing.
　　Cleavage stage embryo: The period of cellular mitosis that begins after the fertilisation of a spermatozoa and begins with the division of the syncytium into 2 cells and continues until the third day is called the ‘cleavage stage embryo’.
　　Blastocyst: The cells of the cleavage stage embryo continue to divide and a blastocystic cavity begins to form between the cells, which is filled with fluid. After the formation of the blastocyst, the cells undergo their first differentiation, forming trophoblast ectodermal cells and endodermal cells. This is the 5th to 6th day of development of the fertilised egg.
　　Embryo Freezing: In most cases, several transferable embryos can be formed in a single egg retrieval cycle, but only 1 or 2 embryos need to be transferred at a time, so the extra embryos will be frozen in liquid nitrogen at -196 degrees. Therefore, depending on whether the embryos are frozen or not, they are divided into ‘fresh embryos’ and ‘frozen embryos’.
　　What are the common causes of endometritis?
　　(1) Infection by microorganisms
　　Under normal circumstances, the endometrium has its own defence function, while endometritis is usually caused by childbirth or destroying the defence function and self-purification of the female reproductive tract, increasing the chances of pathogens infecting the reproductive tract and causing inflammation.
　　(2) Related to immune disorders When chronic endometritis occurs, some cytokines (such as pro-inflammatory factors, chemokines, adhesion factors, etc.) are induced by microbial surface antigens of endometrial cells, thus causing abnormal endometrial immune responses, and it has been recently suggested that the number of plasma cells infiltrating the endometrial mesenchyme may be positively correlated with the severity of inflammation.
　　In addition, subfamilies of multiple immunoglobulin IG classes are highly expressed in the oedematous stroma of chronic endometritis, and local immune responses mediated by antibodies to these immunoglobulins may adversely affect the embryo implantation process but rarely progress to a systemic inflammatory response.