Blastocyst Culture
Blastocyst Culture
The core of treatment at our IVF centers is blastocyst culture which allows for the detailed assessment of embryo quality. The fertilization of the oocytes with the sperm takes place outside the female body in the laboratory (IVF/ICSI/IMSI). The fertilized eggs are transferred into a special culture medium and placed in an incubator in order to grow into embryos. Cutting-edge laboratory technology enables the close monitoring and evaluation of embryonic development. Once the embryos have reached a specific stage of development (blastocyst = embryo capable of initiating implantation), those with the highest implantation potential (maximum of 2 embryos) are selected and can subsequently be placed in the woman's uterus. (see "Embryo Transfer").
1. Why opt for embryo transfer at the blastocyst stage?
2. Benefits of blastocyst culture
│ © 2022 Shutterstock/Next Fertility IVF Prof. Zech • Member of Next Clinics
1. Why opt for embryo transfer at the blastocyst stage?
The term "reproductive medicine" already implies the goal of this specialist area, namely to understand and imitate nature down to the smallest detail. Based on the current state of scientific knowledge, blastocyst culture is a key factor in the successful treatment outcome. In IVF treatment involving blastocyst culture (see schematic display above), the fertilization of the oocytes with the sperm takes place outside the female body in the laboratory (IVF/ICSI/IMSI). The fertilized eggs are transferred into a special culture medium and placed in an incubator in order to grow into embryos. Cutting-edge laboratory techniques enable the close monitoring and detailed assessment of embryonic development.
Once the embryos have reached a specific stage of development (blastocyst = embryo capable of initiating implantation), they are transferred to the woman's uterus (see "Embryo Transfer"). In an ideal scenario, embryo transfer is carried out on the 5th day following fertilization which, in normal conception, corresponds to the time when an embryo has travelled via the fallopian tube to the womb in order to attach to the uterine wall. Performing embryo transfer on day 2 or day 3 following oocyte pick-up is at least 2 days too early compared to the in vivo situation. Why is that? Maturation, fertilization and the first 3 cell division cycles are primarily dependent upon the egg cell. The genetic influence of the male sperm does come into play no earlier than from the 3rd day after fertilization and leads to the activation of the embryonic genome (see graph below). This means that blastocyst culture and embryo transfer on day 5 are best suited – according to the state of the art in science and technology – for ensuring that an accurate assessment can be made of the embryo’s potential for implantation.
│ © 2022 Next Fertility IVF Prof. Zech • Member of Next Clinics
2. Benefits of blastocyst culture
The advantages of transferring blastocyst stage embryos on day 5 of culture over embryo transfer on either day 2 or day 3 are supported by numerous high quality publications:
- Better synchronization between uterus (womb) and early embryonic development.
- Condition and quality of the embryo can now be assessed. It is thus possible to select from a given cohort the embryos with the greatest developmental potential for transfer.
- Reduced uterine contractile activity from day 5 onwards. This lowers the likelihood of the transferred embryos being expelled from the womb.
- Greater chance of successful implantation (in the womb)
Blastocyst culture combined with optimized stimulation protocols and transfer techniques offer favorable conditions for achieving successful outcomes. The key prerequisites for achieving such results are excellently equipped laboratories, highly-qualified biologists and longstanding experience in this field.
In 1996, we became the world's first IVF centers to introduce a systematic implementation of blastocyst culture, thus setting standards at the international level. This treatment method, which is aimed at improving the chances of pregnancy, is now regarded as "state-of-the-art" in reproductive medicine. Therefore, our team can now look back on know-how gained from more than 20 years of experience in successful IVF treatment involving extended blastocyst culture.
