‘There is only one thing that is truly important in an IVF laboratory: everything’ Cairo Consensus Guidelines on IVF Culture Conditions

Abstract

Cairo 2018 Consensus Group* KEY MESSAGE This report presents outcomes from an international expert meeting to establish consensus guidelines on IVF culture. Topics reviewed were: embryo culture; temperature; humidity; gas control, pH; workstations; incubators; micromanipulation; handling and assessment; stasis, composition, supplementation, type of culture and storage; equipment and monitoring. More than 50 consensus guideline points were established.

Non-Invasive Human Embryo Metabolic Assessment as a Developmental Criterion

“…The significantly high release of Ala and Gln is consistent with Houghton et al [5], and inconsistent with Sturmey et al, who declared that mouse embryos at blastocyst stages consumed Gln at a significantly higher rate than the early cleavage stages [8]. L-Gln is considered to be an essential component of culture media during embryo development over the 2-to 8-cell stages in a number of species [24,27]. It can be metabolized to other AAs (i.e., Glu, Ala, and Asp) [28] and ATP through the TCA cycle, synthesizes de-novo purine and pyrimidine, protects the embryo against oxidative stress, and acts as an organic osmolyte and a putative regulator in Glc metabolism [8].…”

“…Herein, the most striking data were provided by Ala-Gln dipeptide and non-essential AAs (especially Gln, Tau, Ala, Gly) which demonstrated the net depletion and appearance in the culture media throughout embryo development, respectively. Ala-Gln dipeptide is introduced to all ART culture media as a standard practice because of its higher stability than individual Gln degraded to ammonium spontaneously and metabolically [24]. Although Ala-Gln provides osmoregulation with lower efficacy than individual AAs, it can efficiently reduce the magnified ammonium accumulation in preimplantation embryo culture media [24,25].…”

“…Ala-Gln dipeptide is introduced to all ART culture media as a standard practice because of its higher stability than individual Gln degraded to ammonium spontaneously and metabolically [24]. Although Ala-Gln provides osmoregulation with lower efficacy than individual AAs, it can efficiently reduce the magnified ammonium accumulation in preimplantation embryo culture media [24,25]. The dipeptide may be uptaken within the cells by a specialized dipeptide transporter or an AA transporter after its hydrolyzation into its constituent AAs by secreted or membrane-bound peptidases [26].…”

Efficiency comparison between dry and humid cultures for clinical outcome of the in vitro fertilization-embryo transfer

“…In addition, there was strong evidence that culture conditions with high humidity atmosphere promoted embryo development and reproductive outcome [14]. In the Cairo consensus guidelines on IVF culture conditions, the DC and HC contributed to satisfactory outcome in clinical settings, but the HC was proved to be more suitable for IVF-ET [3]. This is related to the fact that the humidity in the chamber can be modulated through the water evaporation in the humid incubator, which can attenuate the water loss in the culture.…”

“…On this basis, the osmotic pressure of culture medium is stable [1,2], contributing to the culture of zygote and embryo. Therefore, it is recommended as the major method for embryo culture [3].…”