Oocyte cryopreservation: the birth of the first Hungarian babies from frozen oocytes.

Purpose: To present data obtained with clinical application of oocyte cryopreservation.

Methods: Slow freezing/rapid thawing in PBS based medium containing 1.5 M propanediol + 0.3 M sucrose.

Results: A total of 127 embryos were transferred into 54 patients (1.9 embryo/cycle, 64 transfer cycles). Clinical pregnancy rate of 20% per cycle (13/64) and 24.0% per patient were achieved. Up-to-date, six patients delivered seven healthy babies; there are four ongoing pregnancies. Three abortions (23%) and one biochemical pregnancy (0.7%) was obtained. Implantation rates of 11% per transferred embryos (14/127) and 6.5% (14/215) per thawed eggs were found. In each case, normal karyotype was detected. No difference was found in the ratio of spindle positive oocytes at the polscope analyses done before and after freezing (75.8% vs. 82.5%).

Conclusion: Egg freezing is not a routine procedure yet, but there will certainly be a place for it in the future of assisted reproductive medicine.