Blastocyst culture allows the embryo to be observed for a longer period of time before it is returned. If it develops optimally during this time, the probability of pregnancy increases.
In the case of In-Vitro Fertilisation (IVF) or Intracytoplasmic Sperm Injection (ICSI), the embryos are usually transferred into the uterine cavity during on the second or third day after egg retrieval. At this point, they consist of around two to eight cells. With a blastocyst culture, the culture period is extended to up to five days. The embryos then comprise up to 128 cells and are called blastocysts. Unfortunately, not every embryo reaches this stage.
The embryos that actually develop into blastocysts promise a better implantation success rate and therefore a higher probability of resulting in a pregnancy. Under certain circumstances, this method is suitable for couples who have not achieved pregnancy even after several embryo transfers.