Embryo catheter loading and embryo culture techniques: results of a worldwide web-based survey

Abstract

Responses from 265 centers in 71 countries were obtained. Most centers (97 %) preferred a catheter with its orifice on top, with only 3 % preferring a catheter with the orifice on its side; 41 % preferred a catheter marked for clear ultrasound view. The most commonly-reported methods of embryo loading were medium-air-embryo-air-medium (42 %), medium in catheter with embryo at end (20 %) and medium-air-embryo (15 %). In 68 % of centers the final volume of the catheter was up to 0.3 ml, with only 19 % using 0.3-0.5 ml and 1 % using 0.5-0.7 ml. Using reduced oxygen concentrations for embryo culture was divided between those who used it in combination with the two-gas system (34 %) and those who did not use it at all (39 %); 24 % reported using a three-gas system. Most clinics using reduced oxygen concentrations used it throughout the entire culture period. Half of centers (51 %) reported using reduced oxygen concentrations for the entire IVF population while 6 % reserved it only for blastocyst transfer. The use of sequential media was highly dominant with 40 % reporting its use.

The Microenvironment of Human Implantation: Determinant of Reproductive Success

“…In women, the single implantation site is normally found at the uterine fundus . If this is the case, then it may be that transfer of embryos into the uterine cavity, in a drop of fluid (20–60 μL) as routine in IVF clinics, may modify its positioning, as may inclusion of air bubbles in the transfer catheter . Molecular mechanisms underlying the regulation of uterine fluid volume are likely to include actions of aquaporins (AQP), a family of transmembrane water channels, of which AQP2, 5 and 8 are dynamically regulated in the human uterine epithelium .…”

Combined effects of individual culture and atmospheric oxygen on preimplantation mouse embryos in vitro

“…The widespread adoption of these technologies has therefore resulted in individual embryo culture becoming a standard procedure for many clinics. While some human IVF clinics culture embryos in groups, a recent web survey of 265 clinics from 71 countries indicated that 55% of clinics routinely culture human embryos individually during at least part of the culture period (Christianson et al, 2014). Some of these single embryos will be cultured in microwells, which can improve embryo development compared with single culture in a drop (Chung et al, 2015;Dai et al, 2012;Vajta et al, 2008), but many single embryos are cultured in conventional drops with a wide variety of volumes (Bolton et al, 2014).…”

Oxygen tension in embryo culture: does a shift to 2% O2 in extended culture represent the most physiologic system?

“…In fact, a recent survey of embryo culture practices collected from 265 clinics representing 54 countries reported that <25% of programs exclusively utilize 5% oxygen tension during embryo culture [24].…”