Despite a time limit imposed in many countries on the freeze-storage of sperm, a new study has found that the long-term cryopreservation of semen does not affect future clinical outcomes.
The analysis included 119,558 specimens retrieved using a database of young adults who were qualified sperm donors at the Hunan Province Human Sperm Bank of China between 2001 and 2016. The samples were arranged in three groups: those kept in cryostorage for between six months and five years; those stored for between six and 10 years; and those stored for between 11 and 15 years.
The study found the sperm’s frozen-thaw survival rate decreased from 85.72 per cent to 73.98 per cent after 15 years of cryopreservation (P<.01>
However, the clinical pregnancy rate of women undergoing artificial insemination by donor was 23.09 per cent, 22.36 per cent and 22.32 per cent in the three groups, while the live birth rate was 82.17 per cent, 80.21 per cent and 80.00 per cent in the groups. Success rates were comparable when the samples were used in IVF, with live birth rates of 81.63 per cent, 79.11 per cent and 73.91 per cent respectively.
Nevertheless, the authors recommended sperm banks should provide sperm in order of cryopreservation.