Age-specific probability of live birth with oocyte cryopreservation: An individual patient data meta-analysis

Objective: To estimate age-specific probabilities of live birth with oocyte cryopreservation in nondonor (ND) egg cycles. Design: Individual patient data meta-analysis. Setting: Assisted reproduction centers. Patient(s): Infertile patients undergoing ND mature oocyte cryopreservation. Intervention(s): PubMed was searched for clinical studies on oocyte cryopreservation from January 1996 through July 2011. Randomized and nonrandomized studies that used ND frozen-thawed mature oocytes with pregnancy outcomes were included. Authors of eligible studies were contacted to obtain individual patient data. Main Outcome Measure(s): Live birth probabilities based on age, cryopreservation method, and the number of oocytes thawed, injected, or embryos transferred. Result(s): Original data from 10 studies including 2,265 cycles from 1,805 patients were obtained. Live birth success rates declined with age regardless of the freezing technique. Despite this age-induced compromise, live births continued to occur as late as ages 42 and 44 years with slowly frozen and vitrified oocytes, respectively. Estimated probabilities of live birth for vitrified oocytes were higher than those for slowly frozen. Conclusion(s): The live birth probabilities we calculated would enable more accurate counseling and informed decisions for infertile women considering oocyte cryopreservation. Given the success probabilities, we suggest that policy makers should consider oocyte freezing as an integral part of prevention and treatment of infertility.