Mocanu, Edgar Cottell, Evelyn Waite, K Hennelly, Bernadette Collins, Claire Harrison, Robert F. Frozen-thawed transfer cycles: are they comparable with fresh? <p>Cryopreservation of zygotes and subsequent thaw and transfer is an established ART treatment. We assessed if success rates frozen-thawed (day 2) zygotes are comparable with the outcome in fresh cycles of treatment. We performed a prospective follow-up and analysis of all frozen (FZT) and fresh cycles of treatment during a 12 months period. One hundred and nineteen patients in the frozen-thawed and 652 in the fresh group had a transfer. The overall thaw-survival rate was 71.7%. Clinical pregnancy rates per thaw and transfer were respectively 15.1% and 21% in the frozen and 29.1% (per transfer) in the fresh group. Implantation rates in fresh and frozen cycles were 16% and 12.3% respectively. The pregnancy loss rate was higher in the FZT group (29% vs. 18.3%). Cryopreservation of good quality zygotes, after fresh transfer offers optimal success rates in subsequent frozen treatment. It also encourages consideration of elective single zygote transfers.</p> Cryopreservation;Embryo Implantation;Embryo Transfer;Female;Fertilization in Vitro;Humans;Infertility;Pregnancy;Pregnancy Rate;Multiple;Reproductive Techniques;Assisted;Zygote;Obstetrics and Gynaecology 2019-11-22
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