To the Editor The report by Dr Kushnir and colleagues1 concluded that the use of cryopreserved donor oocytes was inferior to the use of fresh donor oocytes for in vitro fertilization and embryo transfer. We have concerns about their methods.
In their study, live birth rates were compared between in vitro fertilization cycles using fresh and cryopreserved donor oocytes. In our center, fresh donor cycles produced an average of 19 oocytes from which to select the best embryo for transfer, whereas only 11 oocytes were available using cryopreserved oocytes.2
Grifo JA, McCulloh DH, Statman LY. Fresh vs Cryopreserved Donor Oocytes. JAMA. 2015;314(23):2569-2570. doi:10.1001/jama.2015.13447