What are the reasons for establishing EGP?

The initiators and founders, i.e. the team of the IVF Centers Prof. Zech believes that urgent action is needed as to the current grouping of the women in so-called responder-groups (Low / Poor, Normal, High). The reason: An accurate and uniform definition of these "responder"- groups and a holistic view of the different components that may influence a fertility treatment are still missing!

Typically, the responder-groups reflect the expected number of oocytes for a specific age group after hormonal stimulation and egg retrieval. Sperm quality, fertilization rate and embryo developmental potential have not been taken into account here.

For the team of the IVF Centers Prof. Zech it is therefore clear that it is not sufficient to determine the number of oocytes in order to provide the couples with meaningful predictions regarding the possible success of the treatment. What matters is to view together female and male factors and give a prognosis based on blastocyst outcome.

That is what EGP is aimed at!

Why is blastocyst culture a crucial factor?

The EGP standard defines blastocyst outcome as a common denominator. This is due to the interaction of parental factors during the first five days of embryonic development. The onset of the embryonic genome that only takes place between the 2nd and the 3rd day of embryonic development brings about the influence of paternal factors. It is quite common in fertility treatment that women being classified as "Low / Poor Responder" can, nonetheless, achieve a good blastocyst outcome. It is therefore not the number of oocytes retrieved that matters, but the blastocyst outcome that should be taken into consideration in order to predict individual success rates.

Case studies from the IVF Centers Prof. Zech

In order to reflect the expected developmental potential of the female and male gametes (EGP), the profiles of the couples undergoing fertility treatment were classified into three categories: “below EGP, “EGP” and “above EGP”. To this end, the following parameters are used, among others, for prognosis:

  • Age of the couples
  • Specific stimulation protocol
  • Precise sperm analysis (IMSI - Intracytoplasmic morphological selected sperm injection)
  • Fertilization rate
  • Specific protocol for blastocyst culture
  • High quality standard of the laboratories in the IVF Centers Prof. Zech
  • Vitrification technique
Case A: 33-year-old female with a 42-year-old male partner, mild oligozoospermia, and secondary idiopathic sterility after biochemical pregnancy.
Cycle outcome:7 oocytes obtained at pick-up; 6 mature oocytes; all 6 were fertilized (FR 100%); 5 good quality blastocysts on day 5; transfer of 2 blastocysts (Bl 5BA, Bl 4AB) and birth of one boy; and cryopreservation of 3 blastocysts.
Semen analysis: 2.6 ml; 11 Mio/ml; progressive motility: 57%; and IMSI report: 8% Class I, 51% Class II, and 41% Class III sperm.
Case B: 35-year-old female with a 38-year-old male partner, normozoospermia, and primary sterility by obstruction of the fallopian tubes.
Cycle outcome:11 oocytes obtained at pick-up; 10 mature oocytes; all fertilized (FR 100%); 1 blastocyst (fBl c); transfer of 1 blastocyst; no pregnancy in this cycle.
Semen analysis:3.5 ml; 18.4 Mio/ml; progressive motility: 55%; and IMSI report: 0% Class I, 25% Class II, and 75% Class III sperm.
Case C: 34-year-old female with a 37-year-old male partner, paraplegic, oligoasthenozoospermia, and primary sterility.
Cycle outcome:16 oocytes obtained at pick-up; 13 mature oocytes; 12 fertilized (FR 92.3%); 5 blastocysts (4 good quality and 1 very low quality); transfer of 1 blastocyst (Bl 2AB) and birth of one healthy girl; and cryopreservation of 3 blastocysts.
Semen analysis:1 ml; 2.5 Mio/ml; progressive motility: 5%; and IMSI report: 0% Class I, 11% Class II, and 89% Class III sperm.

Grafik_IVF Zentren Prof. Zech_Kinderwunsch

[Figure 1: Classification of cases A, B, and C into prognosis groups based on number of oocytes (poor responder: 1-8 oocytes, normal responder: 9-12 oocytes, or high responder: >12 oocytes), fertilization rate FR (%) classified as normal between 80-100%, or blastocyst outcome on day 5 (below EGP: 1-3 blastocysts, EGP: 4-5 blastocysts, or above EGP: >5 blastocysts).]