Random start controlled ovarian hyperstimulation for fertility preservation during incidental pregnancy: a case report of blastocyst vitrification from matured oocytes.

Here, we present a diffuse large B cell lymphoma patient admitted for fertility preservation before cancer therapy and whose pregnancy was recognized incidentally just after the start of random start controlled ovarian stimulation (RSCOH) during the stimulation cycle. Despite an optimal homogenous growth of follicle cohort, majority of the retrieved oocytes were immature after GnRHa trigger. Possible effects of extremely high serum progesterone and/or β-hCG levels on oocyte maturation are discussed with the surprising high rate of maturation and subsequent good embryo development. It seems that in case of need for pregnancy termination as a result of an urgent cancer therapy, RSCOH can be started and patients may benefit from overnight maturation of oocytes.