Problem statement and background data
Embryo vitrification – first described 25 years ago – was recently adapted to general use in ART. Practically, vitrification has enabled to cryopreserve and de-vitrify zygotes (day-1) and blastocyst-stage embryos with nearly no losses. These outstanding results have triggered enthusiasm and outlined several immediate clinical indications for vitrifyingembryos and differing ET:

1. For avoiding OHSS
2. When facing an intrauterine pathology (polyp, fibroid, endometrial fluid)
3. For certain patient populations (i.e. after several ART failures)
4. After GnRH-a trigger in antagonist protocols

Vitrification has thus made an old dream of ART come true – to dissociate COS and its harm to the endometrium from ET (Fig. 1). A perfect mastering of priming endometrial receptivity with exogenous hormones – as developed for donor-egg ART – has comforted doctors about the soundness of a new differed ETapproach.

The advent of GnRH antagonist protocols has also empowered the possibility of triggering the final stage of ovulation with GnRH-a. This induces an elevation of endogenous LH – and FSH – of sufficient magnitude for reliably collecting an oocytes harvest comparable to that achieved with hCG. GnRH trigger provides oocytes of good quality, as evidenced by good pregnancy rates in donor-egg ART, while avoiding the risk of OHSS. But, the short-lived elevation of LH obtained with GnRH trigger, causes some endometrial alterations that hamper fresh ETs' results thus, justifying systematic vitrification and differ ET in the eyes of some.

Why a website-based worldwide survey?

An ultra rapid diffusion through the Internet of new techniques such as GnRH trigger, embryo vitrificationand differed EThas upended certain ART practices based on relatively few –sometimes-preliminary– published data. Certain new medical techniques, sexy and appealing as they may be, indeed spread more rapidly than before Internet times. This therefore carries the risk of exposing far more patients than ever before to the risks of a teething process taking worldwide dimensions.

The broad instant-diffusion of information on new medical practices through the Internet is however a no-turn back one-way process. We should therefore accommodate this process with enhanced Internet-supported adjustment means for assessing and correcting, rather than merely lamenting on some sinister consequences of our modern world. Internet-supported assessment of new practices is indeed warranted for limiting some possible unwonted consequences inherent to a rapid worldwide instant diffusion of new possibly premature practices. With this in mind, IVF-Worldwideis undertaking an Internet-based survey of GnRH trigger, vitrificationand differed ETpractices. This survey aims at further defining the merit, possible limitations and needed adjustments that these new techniques may mandate to implement at a pace that is set to match that of their diffusion.

Conclusion

In times of Internet instant-diffusion of new medical practices, communication means such as offered by IVF worldwide should be deployed for assisting the new worldwide teething processes.