Algorithm-based individualization methodology of the starting gonadotropin dose in IVF/ICSI and the freeze-all strategy prevent OHSS equally in normal responders: a systematic review and network meta-analysis of the evidence

PURPOSE: Ovarian hyperstimulation syndrome (OHSS) represents a rare but dangerous condition associated with controlled ovarian stimulation (COS) in IVF/ICSI. Over the last decades, many strategies have been introduced into clinical practice with the objective of preventing this potentially life-threatening condition. Among these, the freeze-all policy has gained great popularity, thanks to improvements in vitrification. Nevertheless, not all clinics have adequate skills in vitrification procedures and patients may be dissatisfied with a longer time to pregnancy. METHODS: This study is a systematic review and network meta-analysis of randomized controlled trials comparing different strategies of ovarian stimulation in IVF/ICSI cycles (freeze-all policy, algorithm-based individualization of the starting dose, experience-based individualization of the starting dose, standard dose) in terms of reduction of OHSS, in normal responders. RESULTS: The results indicate that only the algorithm-based individualization of the starting gonadotropin dose reduces OHSS similarly to the freeze-all strategy. CONCLUSION: Albeit in the era of the freeze-all policy, the personalization of the starting gonadotropin dose obtained by the use of algorithms should be pursued as a valid and safe option for IVF. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10815-022-02503-2.