The feasibility of switching from IVF to IVM combined with all‐blastocyst‐culture and transfer for patients with ovarian hyperstimulation syndrome tendency

To investigate the feasibility of switching from in vitro fertilization (IVF) to in vitro maturation (IVM) combined with all-blastocyst-culture and transfer as a supplementary infertility treatment in patients with ovarian hyperstimulation syndrome (OHSS) tendency METHODS: Retrospective cohort study including 184 patients who switched from IVF and underwent 192 IVM cycles between January 2016 and December 2020. The outcomes were compared between cleavage-stage embryo transfer (group A, n = 74) and blastocyst-stage transfer (group B, n = 52) groups.The OHSS rate is 0%. 66 cycles were canceled for transfer. Among the 126 transfer cycles, number of retrieved oocytes, proportion of metaphase II oocytes, cleavage rate, and proportion of high-quality embryos on day 3 post-fertilization are significantly lower in group A than that in group B. On the contrary, number of transferred embryos is significantly lower in group B than that in group A, whereas the rates of implantation, clinical pregnancy, and live births are significantly higher in group B than that in group A.Timely switching to IVM combined with all-blastocyst-culture and transfer for patients undergoing controlled ovarian hyperstimulation and exhibiting characteristics of OHSS tendency is feasible as a supplementary infertility treatment.