A novel solution for freezing individual spermatozoa using a right angular cryopiece embedded in a grooved petri dish

Herein, we introduced a novel individual sperm freezing device named SpermCD, which consists of a right angular cryopiece (RA-Cryopiece, or "C") and a grooved petri dish ("D"). SpermCD allows embryologists to transfer sperm and perform ICSI on the same focal plane. Thirty-five patients underwent single sperm cryopreservation using SpermCD, including four patients with non-obstructive azoospermia (NOA), 14 patients with virtual azoospermia and 17 patients with cryptozoospermia. One hundred and twenty-five cryopreserved spermatozoa from nine patients were thawed on the day of the oocyte retrieval and 121 spermatozoa were found, with a sperm recovery rate of 97.1 ± 4.6%. Sixty-five MII oocytes from their spouse were injected with thawed sperm. Normal fertilization and high-quality embryo rates were 68.0% ± 33.2% and 24.4% ± 22.2%. Nineteen transplantable embryos were formed after fertilization with frozen sperm, eight of which were transplanted in five couples, resulting in four successful deliveries. SpermCD is a simple and practical individual sperm freezing device.