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Expert Working Groups (EWG)

GFMER Global Consultation on WHO Infertility Guidelines
EWG: Ovarian stimulation for ART

This working group is composed of clinicians from Europe and the United States, who have been working with controlled ovarian stimulation for ART. The aims are to provide WHO guidelines on how to optimise the ovarian stimulation, both in terms of efficacy (delivery rate per stared cycle), and also in terms of risks (ovarian hyperstimulation syndrome). The work covers mostly standard patients, but also low responders. The topis include how to predict the response and to stimulate with most appropriate regimens and gonadotropin doses, the luteal phase support and the feasibility of ”low-cost” drug regimens.

Anders Nyboe Andersen
Chair, EWG Ovarian stimulation for ART 

Chair: Anders Nyboe Andersen (Denmark)


  • Georg Griesinger (Germany)
  • Basil Tarlatzis (Greece)
  • Alan Penzias (USA)
  • Frank Broekmans (Netherlands)



Population Intervention Comparator Outcome (PICO):
Being developed to find the evidence in order to determine if a Recommendation on best practice can be made by the World Health Organization concerning the following topic.


(P = women of reproductive age – questions may include exclusion or inclusion criteria)

Should WHO develop a recommendation concerning:

  1. use of specific protocol or drugs and drug doses to increase pregnancy rates in patients who are ”low responders”?
  2. single or combined parameters that could be used to predict the ovarian response to COS (low or excessive ovarian response).
  3. the dose of FSH and the protocol that can be individualised to optimise the ovarian response and thus balance efficacy (pregnancy rates) and risks (OHSS).
  4. efficacy, efficiency and risks of the two most frequently used protocols: GnRH antagonist versus long agonist protocols?
  5. use of the GnRH antagonist protocol with GnRH agonist triggering in oocyte donors.
  6. how to schedule progesterone luteal support after COS.
  7. whether ”low cost (affordable)” COS have been tested to such an extent that efficacy is documented.