Evaluation of live birth rates and perinatal outcomes following two sequential vitrification/warming events at the zygote and blastocyst stages.

Purpose: To study the outcome of sequential cryopreservation-thawing of zygotes followed by the cryopreservation-thawing of blastocysts in the course of an IVF treatment on live birth rate and neonatal parameters.

Methods: Single center, retrospective chart review for the time period of 2015-2020. Clinical and perinatal outcomes were compared between frozen embryo transfer cycles utilizing twice-cryopreserved (n = 182) vs.

A randomised, multi-center, open trial comparing a semi-automated closed vitrification system with a manual open system in women undergoing IVF.

Study Question: What are outcome and procedural differences when using the semi-automated closed Gavi® device versus the manual open Cryotop® method for vitrification of pronuclear (2PN) stage oocytes within an IVF program?

Summary Answer: A semi-automated closed vitrification method gives similar clinical results as compared to an exclusively manual, open system but higher procedure duration and less staff convenience.

What Is Known Already: A semi-automated closed vitrification device has been introduced to the market, however, little evaluation of its performance in a clinical setting has been conducted so far.

Study Design, Size, Duration: This prospective, randomised, open non-inferiority trial was conducted at three German IVF centers (10/2017-12/2018).

What is the net effect of introducing vitrification for cryopreservation of surplus 2PN oocytes in an IVF program?

Purpose: The aim of this study was to accurately describe outcome differences (cryo-survival, pregnancy rate and live birth rate, both per ET and cumulatively), between the vitrification method and slow-freezing method of surplus 2PN oocytes in an IVF program.

Methods: In 2004, the freezing method for 2PN oocytes was changed from slow-cooling to vitrification. The data of 711 patients (timespan: 1/1999-7/2011; 410 vitrification and 301 slow-cooling events) undergoing a first IVF/ICSI cycles with freezing of 2PN oocytes were retrospectively analyzed.

Three years of routine vitrification of human zygotes: is it still fair to advocate slow-rate freezing?

Cryopreservation of human oocytes and embryos is a necessary tool in assisted reproduction treatment that leads to an increased cumulative outcome while decreasing costs. Vitrification is a cryopreservation technique that leads to a glass-like solidification, with rapid cooling of cells or tissues. Nowadays vitrification is claimed to be the future of cryopreservation of human embryos due to improved survival rates and clinical outcomes.