Calculating the implantation potential of day 3 embryos in women younger than 38 years of age: a new model

E. Van Royen
2001 Human Reproduction  
For optimal embryo selection in IVF/intracytoplasmic sperm injection (ICSI), knowledge of the implantation potential is essential. This is a retrospective analysis of morphological characteristics and cleavage kinetics of day 3 embryos resulting in an objective assessment of the relative implantation potential of each distinct type of embryo. Therefore transferred embryos were sampled according to their documented implantation behaviour: all embryos without any implantation on the one hand and
more » ... n the one hand and all those with 100% ongoing implantation on the other. There were 213 such embryos in the latter group of which only seven (3%) had >20% fragmentation and only one embryo (0.5%) showed multinucleation (an embryo containing >20% fragmentation). For this reason, only embryos with ≤20% fragmentation and without multinucleation were analysed. They were split up according to the amount of fragmentation and the number of blastomeres on day 2 and on day 3. For each type, the implanted fraction was calculated, i.e. the number certainly implanted divided by the sum of the number certainly implanted and the number certainly not implanted, thus describing its relative implantation potential. By extrapolation to the entire population it was possible to establish the implantation potential for each type of embryo. Optimal day 3 embryos were calculated to reach a mean of 47% ongoing implantation. By establishing the implantation potential for most embryos, this model also provides useful information about which embryos are worth freezing in a cost-effective cryopreservation policy. Key words: blastomere/embryo/fragmentation/implantation potential/pregnancy Patients were treated with the long protocol for ovarian stimulation. Desensitization was initiated in the midluteal phase with busereline et al., 1995). Pickering et al. showed that multinucleation is 326
doi:10.1093/humrep/16.2.326 pmid:11157828 fatcat:id5xepuxmjfsvptue4aeue6nh4