Planned oocyte cryopreservation-10-15-year follow-up: return rates and cycle outcomes

To evaluate the outcomes of planned oocyte cryopreservation patients most likely to have a final disposition.

Retrospective cohort study of all patients who underwent at least 1 cycle of planned oocyte cryopreservation between Jan 2005 and December 2009.

Large urban University-affiliated fertility center PATIENT(S): All patients who underwent ≥1 cycle of planned oocyte cryopreservation in the study period.

None MAIN OUTCOME MEASURE(S): Primary outcome was the disposition of oocytes at 10-15 years. Secondary outcomes included thaw/warming types, laboratory outcomes, and live birth rates. Outcomes and variables treated per patient.

A total of 231 patients with 280 cycles were included. The mean age at the first retrieval was 38.2 years (range 23-45). A total of 3,250 oocytes were retrieved, with an average of 10 metaphase II frozen/retrieval. To date, the oocytes of 88 patients (38.1%) have been thawed/warmed, 109 (47.2%) remain in storage, 27 (11.7%) have been discarded, and 7 (3.0%) have been transported elsewhere. The return rate (patients who thawed/warmed oocytes) was similar by Society for Assisted Reproductive Technology age group. The mean age of patients discarding oocytes was 47.4 years (range, 40-57). Of the 88 patients who thawed/warmed oocytes, the mean age at the time of thaw/warming was 43.9 years (range, 38-50) with a mean of 5.9 years frozen (range, 1-12). Nine patients (10.2%) thawed/warmed for secondary infertility. A total of 62.5% of patients created embryos with a partner, and 37.5% used donor sperm. On average, 14.3 oocytes were thawed/warmed per patient, with 74.2% survival (range, 0%-100%) and a mean fertilization rate of 68.8% of surviving oocytes. Of 88 patients, 39 (44.3%) planned a fresh embryo transfer (ET); 36 of 39 patients had at least 1 embryo for fresh ET, and 11 had a total of 14 infants. Forty-nine of 88 patients (55.7%) planned for preimplantation genetic testing for aneuploidy, with a mean of 4.2 embryos biopsied (range, 0-14) and a euploidy rate of 28.9%. Of the 49 patients, 17 (34.7%) had all aneuploidy or no embryos biopsied. Twenty-four patients underwent a total of 36 single euploid ET with 18 live births from 16 patients. Notably, 8 PGT-A patients had a euploid embryo but no ET, affecting the future cumulative pregnancy rate. Overall, 80 patients with thaw/warming embryos had a final outcome. Of these, 20 had nothing for ET (arrested/aneuploid), and of the 60 who had ≥1 ET, 27 had a total of 32 infants, with a live birth rate of 33.8% (27/80).

We report the final outcomes of patients most likely to have returned, which is useful for patient counseling: a utilization rate of 38.1% and a no-use rate of 58.9%, similar across age groups. Further studies with larger cohorts as well as epidemiologic comparisons to patients currently cryopreserving are needed.