Sequential clomiphene/corifollitrophin alpha as a technique for mild controlled ovarian hyperstimulation in IVF: a...

Mild controlled ovarian hyperstimulation (COH), combined with oocyte retrieval (OR) under local anaesthesia (LA), may provide low-impact IVF. Since a single injection of corifollitrophin alfa (CFA) provides 7 days of COH, we hypothesised that clomiphene-citrate (CC) followed by CFA may provide adequate COH response from one single FSH injection. Therefore, the aim was to assess IVF outcomes after a novel clomiphene citrate/CFA (CC/CFA) protocol, compared to women undergoing standard rFSH COH protocols (good prognosis comparative cohort:GPCC) in a 1:2 matched design.

In this pilot study of 25 patients (ANZCTR id:ACTRN12612000740897, MINIVA:Minimal_Stimulation_in_IVF), we examined the effectiveness of oral clomiphene (100 mg-days 2-6) followed by CFA in a GnRH antagonist protocol producing a single injection COH stimulation regime. All OR were conducted under LA pre-ovarian block. Cycle outcomes were compared to a matched good prognosis comparative cohort (GPCC) undergoing standard rFSH COH.

Mild stimulation was achieved with less oocytes being collected compared to the GPCC (6.4 ± 0.7 vs. 10.7 ± 0.9, p < 0.001), resulting in a reduced number of good quality embryos available for transfer/cryopreservation (3.7 ± 0.6 vs. 5.7 ± 0.5, p = 0.01). While embryo quality was similar between the two groups, endometrial thickness was significantly lower in the group receiving CC/CFA. Pregnancy rates were significantly lower in the CC/CFA cohort compared to GPCC (31.8 vs. 57.1%, p = 0.04) and 44% of CC/CFA participants required supplemental rFSH in order to achieve the hCG trigger criteria.

Sequential clomiphene CFA protocol does not appear to be an optimal regime for low impact IVF treatment as it does not provide adequate COH from a single CFA injection and results in lower fresh embryo transfer pregnancy rates and fewer embryos for cryopreservation.