Many patient who has undergone in vitro fertilization (IVF) will have heard of the blastocyst culture techniques that can be used to improve the clinical pregnancy rate. When blastocyst culture processes are applied to in vitro cultures, further screening is possible. This ensures that the embryos are of high quality and have optimum developmental potential, thereby improving the clinical pregnancy rate.

After the eggs and sperm have been retrieved, insemination (IVF or ICSI) is performed in an embryology laboratory to create a fertilized egg, called a zygote. The zygote develops over three days until it has cleaved into 8-10 cells on Day 3. At this point, it is called a Day 3 cleavage embryo.

If the embryo continues to develop for an additional 2-3 days, the embryo will develop into a blastocyst. The process of development from a Day 3 cleavage embryo to a blastocyst is called blastocyst culture.

Blastocyst culture requires an optimal and constant culture environment. This includes a culture microenvironment with stable parameters such as temperature, osmotic pressure, and pH value, as well as a stable incubator and laboratory environment that is equipped with a high-efficiency laminar flow filtration system。

The process whereby blastocysts are transferred into the mother's uterus is called blastocyst transfer. Typically, under controlled physical conditions, the greater the success rate of blastocyst culture, the higher the success rate of IVF. 

Reference:

1.      中华医学会，2009，临床诊疗指南-辅助生殖技术与精子库分册，北京人民卫生出版社。

2.      American Society for Reproductive Medicine. Revised guidelines for human embryology and andrology laboratories. FertilSteril 2008; 90:S45-59