Extended assessment of mild ovarian stimulation.

Abstract Sterrenburg The aim of the work presented in this thesis was to look for strategies to improve the burden of ovarian stimulation for IVF and OVIN treatment without compromising the outcome. The specific focus will be on the following three questions: (1) Are ovarian response level and probability of pregnancy related? (2) What is the clinical efficacy of a single dose, long acting FSH preparation in OVIN and IVF treatment? (3) Can the mild stimulation antagonist protocol for IVF be improved by late start of rFSH? The relation between number of oocytes and outcome in terms of pregnancy are explored in part 1. The drawback of decreased ongoing implantation rate in high responders in mild stimulation thereby is further investigated. Also the question will be analysed what the optimal daily stimulating dose would be in expected normal responders, based on a systematic review of the existing literature. Part 2 describes the studies of a new compound, long-acting FSH, to find out if reducing the number of injections with this new medication would be as safe and efficient as rFSH in OVIN and IVF treatment. In part 3 a mild stimulation protocol is studied to discern whether the burden for patients can be reduced while avoiding a detrimental effect on morphological markers of embryo quality. The prospective randomised study described in this chapter also investigates the endocrine characteristics, the follicular development, and the clinical applicability of a mild stimulation protocol (start rFSH on cycle day 5) compared with the regular protocol (start rFSH on cycle day 2) in IVF with GnRH antagonist as co-treatment. Finally, in chapter 8 the final answers to the three questions will be discussed based on the conducted studies and the existing literature. The implications in the context of current practice and future research are discussed.