Minimal Stimulation In Vitro Fertilization: A Better Outcome

In in vitro fertilization (IVF) programme, the advantages of mild-stimulation have long been appreciated, while there was a called for more patient-friendly approach in ovarian stimulation around 20 years ago (1). However, the concept is yet to get wide-spread acceptance in the IVF community. The main impediment has been a lack of robust outcome data that can assure the success of mild-IVF at least as good as those of conventional IVF. The randomized controlled trials (RCTs) that compared sequential clomiphene citrate (CC) and low-dose gonadotropins (as mild/ minimal stimulation) with conventional long protocol were either small in sample size or heterogeneous in character (2). Nevertheless, recent meta-analyses and systematic reviews found no difference in pregnancy rates or live birth rates (LBRs) between sequential CC-gonadotropin protocol and conventional IVF (3, 4). More recently, a prospective cohort of 163 good prognosis patients undergoing IVF with sequential CC and low-dose gonadotropin regimen reported a cumulative-LBR (C-LBR) of 70% from a fresh and subsequent frozen embryo transfer (ET) up to 3 cycles (5). A large retrospective cohort study of 20, 244 cycles from Japan using a protocol comprising of extended CC (up to the trigger day)+gonadotropin and subsequent single vitrified-thawed ET found the treatment outcomes of in all age-groups were comparable with those in the Registry of the Society for Assisted Reproduction (SART) in the USA (6).