Jennifer F. Kawwass, M.D., Sara Crawford, Ph.D., Heather S. Hipp, M.D.
To characterize national outcomes of oocyte thaw (OT) cycles.
Retrospective descriptive study.
All autologous OT cycles reported to the Society of Assisted Reproductive Technology Clinic Outcome Reporting System from 2012 to 2018.
All women undergoing OT cycles in the United States.
Main Outcome Measure(s)
Absolute numbers of oocyte cryopreservation (OC) and OT cycles over time. Among OT cycles, patient and cycle characteristics, the ratio of the total number of oocytes thawed to the number of live births by maternal age at the time of cryopreservation (ATOC), and outcomes including pregnancy, miscarriage, live birth, and good perinatal outcome (GPO) by age ATOC.
From 2012 to 2018, 54,675 OC and 6,413 OT cycles were performed; the absolute numbers increased from 2,719 to 13,824 and from 348 to 1,810, respectively. The ratio of the total number of oocytes thawed to the number of live births increased significantly with increasing age ATOC, from 41.4 (age <35 years) to 122.4 (age >41 years). Among OT cycles resulting in embryo transfer, the live birth rate decreased with increasing age ATOC from 42.8% (age <35 years) to 10.8% (age >42 years). The live birth rate was higher when calculated per transfer (42.8% in women aged <35 years ATOC) rather than per thaw cycle (31.5% in women aged <35 years ATOC) because of the number of patients with no transfer. Among 1,124 cycles resulting in pregnancy, the chance of a GPO was highest among women aged <35 years ATOC (65.8%) and decreased as age at ATOC increased.
Among reported OT cycles, the rates of pregnancy and live birth decreased as age ATOC increased. The number of oocytes thawed to achieve one live birth increased significantly with increasing age ATOC. In addition, among the resulting pregnancies, the rate of GPO decreased as age ATOC increased.