Limitations
Limitations of this study include that all participants were from a single centre, and as such, there is potential for bias. Moreover, the decision to give either GnRH antagonist or dual trigger were made on an individual basis and based on clinical judgment, including consideration of previous response to stimulation along with baseline AMH and AFC and E2 levels on the day of trigger. The lack of strict criteria introduces the potential for bias in this analysis. All of the above could be minimised by the use of a multi-centre randomised powered study.