IVM rescue in high responders patients at risk of OHSS

Abstract
Objective: In this pilot study, we tested the hypothesis that, after a few days of FSH administration conventional COH cycles (either daily long GnRH agonist protocols or GnRH antagonist regimens) can be converted into IVM cycles before hCG administration, when follicle count and estradiol levels are high and follicle sizes are small, preventing OHSS risk and cycle cancellation.
Results: Eight patients were initially enroled for a IVF-ICSI treatment, of whom 5 were treated with GnRH antagonists and 3 with GnRH agonists. At the time of shifting to IVM, all patients showed high total follicle count (19.1 ± 6.7), high estradiol levels (1760.6 ± 786.8), and a leader follicle no larger than 12 mm. No trigger with hCG was used before oocyte recovery. The mean oocyte recovery rate was 9.25 ± 5.41, with an oocyte maturation rate after in vitro culture of 60.8%. In all patients, 1 to 2 fresh embryos were transferred, achieving three clinical pregnancies with one live born. None of the patients developed early or late OHSS.
Conclusion: Shifting of a COH cycle to IVM during an early phase of FSH stimulation could expand the range of possibilities to rescue cases at risk of OHSS, when GnRH triggering associated to embryo crypreservation is the only other alternative. This could make possible the transfer of fresh embryos. Further investigation is required to evaluate this hypothesis.

Autori: C.M.M. Brigante, M. Mignini Renzini, M. Dal Canto, G. Coticchio, I. Caliari, R. Fadini