The updated Cochrane review 2014 on GnRH agonist trigger: repeating the same errors

Abstract

Cochrane reviews are powerful tools, internationally recognized as the highest standard in evidence-based health care. A Cochrane analysis makes use of precise, reproducible criteria in the selection of studies for review. In the context of a previous Cochrane review (2010) on the subject of gonadotrophin-releasing hormone agonist (GnRHa) trigger, we questioned whether a review should be conducted during the research phase when new concepts are being developed. Recently, an updated Cochrane review was published, reaching the same general conclusion as the first one, i.e., GnRHa triggers lower the chance of pregnancy in fresh autologous IVF and intracytoplasmic injection treatment cycles. We argue that the new review repeats previous errors by compiling data from studies that were not comparable as different luteal phase protocols were used. From the clinical point of view, the luteal support used is the variable which affects the pregnancy rate and not the use of the GnRHa trigger for final oocyte maturation. Therefore, a meaningful comparison between GnRHa and HCG trigger must be confined to outcome measures that are not affected by the luteal support used. We conclude that the updated review falls short of addressing meaningful clinical and fundamental questions in the context of GnRHa trigger.

Combined ovulation triggering with GnRH agonist and hCG in IVF patients

“…In addition, with the availability of vitrification, segmentation in GnRH agonist-triggered cycles and freezing all oocytes/embryos followed by a frozen transfer in an unstimulated cycle, may be the optimal optimal strategy for eliminating OHSS [4][5][6][7][8][9].…”

Freeze-all en reproducción asistida

“…Sin embargo, este enfoque no es 100% seguro, dado que se han reportado unos pocos casos anecdóticos de OHSS grave después de haber desencadenado la ovulación con aGnRH en ausencia de soporte lúteo (35)(36)(37) . Además, la inducción de la ovulación con aGnRH se ha asociado a defectos en la fase lútea presumiblemente debido a una retroalimentación (feedback) negativa excesiva por parte de los esteroides (38)(39)(40) . Dos revisiones consecutivas de Cochrane por el mismo autor afirman que: 'la inducción de la ovulación con aGnRH está asociada a una tasa de embarazo evolutivo más baja en comparación con la de hCG convencional' (34,41,42) .…”

Current Medical Strategies in the Prevention of Ovarian Hyperstimulation Syndrome

“…Unfortunately, data from studies in the review were not comparable due to diff erent luteal phase protocols used; therefore, the analysis missed the fact that luteal support is the factor which aff ects pregnancy rate and not the use of GnRH agonist trigger for fi nal oocyte maturation 30 . Th erefore, a meaningful comparison between GnRH agonist and hCG trigger must be confi ned to outcome measures that are not aff ected by the luteal support used 31 . Unfortunately, standard luteal phase support after GnRH agonist triggering has been reported to be associated with lower conception rates due to corpus luteum dysfunction.…”