Table 2.
IVM parameters, fertilization rate, embryo development, and pregnancy outcomes
| Vitrified IVM | Fresh IVM | P value | |
|---|---|---|---|
| IVM cycles (n) | 56 | 263 | |
| Median number of oocytes retrieved | 16 (13.3–23.5) | 16 (11–22) | 0.245 |
| Median number of GV | 15 (12–22) | 14 (9–20) | 0.073 |
| Mean number of MII at retrieval | 1.3 (± 2.2) | 1.8 (± 2.5) | 0.096 |
| Median number of oocytes matured in vitro | 10.5 (6.3–15.8) | 8 (5–13) | 0.048 |
| Oocyte maturation rate | 0.7 (± 0.2) | 0.6 (± 0.2) | 0.276 |
| Fertilization and embryo development | |||
| Fertilization rate | 58% (± 24%) | 72% (± 18%) | < 0.001 |
| Rate of embryos reaching cleavage stage (per 2PN) | 74% (± 30%) | 90% (± 16%) | < 0.001 |
| Rate of Good quality embryos (per 2PN) | 17% (± 26%) | 48% (± 29%) | < 0.001 |
| Embryo transfer and pregnancy outcome | |||
| Number of embryos transferred | 3 (2–4) | 4 (3–4) | < 0.001 |
| Implantation rate per transferred embryo | 7/162 (4%) | 134/955 (14%) | < 0.001 |
| Clinical pregnancy rate (%)* | 6/56 (10.7%) | 95/263 (36.1%) | < 0.001 |
| Clinical pregnancy rate per ET cycle (%) | 6/51 (11.8%) | 95/263 (36.1%) | < 0.001 |
| Live birth rate (%)* | 5/56 (8.9%) | 68/263 (25.9%) | 0.005 |
*Calculated per cycle start IVM–in vitro maturation. GV germinal vesicle oocyte, MII metaphase 2 oocyte, 2PN two pronuclei, ET embryo transfer. Data presented as medians (interquartile range) or means (± standard deviation)