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A clomiphene citrate (CC) challenge test was carried out in 114 patients to evaluate the capacity of this test to predict the patient's individual response to controlled ovarian hyperstimulation (COH) performed with a gonadotropin-releasing hormone agonist and human menopausal gonadotrophins (hMG) for in vitro fertilization. The sum of follicle-stimulating hormone measured before and after CC intake, is the parameter that correlated best with subsequent response to COH. The upper limit of the reference value for this parameter, established by considering the CC challenge test performed on 26 patients who became pregnant, was 26.03 mIU/mL. Twenty patients who presented a CC challenge test result above the reference value were compared with patients with a normal test result. For these 20 patients, COH required more hMG and was cancelled in 25% of the cases (instead of 1% in the control group). The number of follicles aspirated, oocytes retrieved, and embryos obtained were on average six times lower than in patients with a CC challenge test result within the reference value, and no pregnancy was obtained. We concluded that CC challenge test provides a reliable individual prognosis for the ovarian response to COH.

One hundred and twenty-one freshly-collected human oocytes and 839 unfertilized human oocytes after insemination were cryopreserved by vitrification. The cryoprotectants used were dimethylsulfoxide (DMSO) and sucrose. Vital staining and morphological criteria were used to assess injuries to cells. Variation of the time exposure to DMSO and sucrose, and cryoprotectants concentrations, followed by extraction-dilution in sucrose without freezing made it possible to study chemical toxicities. Variation of cryoprotectant concentrations followed by immersion in liquid nitrogen, thawing, extraction, and dilution made it possible to choose optimal conditions for vitrification. The sucrose concentration upon extraction after freezing and thawing which was lower than that during soaking enhanced the oocyte survival rate as did the choice of duration and temperature of soaking. No parthenogenetical activation of these unfertilized ovum was observed. This study indicates that with a certain combination of DMSO and sucrose concentrations up to 80% of morphologically intact human oocytes can be recovered after rapid freezing and thawing.

A comparison was made between a serum substitute. UltroSer G (Gibco, Ghent, Belgium) (2%) (medium B) and 10% human fetal cord serum (medium A), as regards their ability to support 1-cell and 2-cell mice embryo development in vitro. Sixty percent and 56% of the 1-cell embryos reached the expanded blastocyst stage when cultured in media A and B, respectively. Eighty-four percent and 88% of 2-cell embryos reached the expanded blastocyst stage when cultured in media A and B, respectively. A prospective randomized study was then performed to evaluate this synthetic serum substitute in human in vitro fertilization. Among 141 ovum pick-up (OPU), oocytes retrieved in 74 cases were processed in medium A and oocytes retrieved in 67 others in medium B. In media A and B, the fertilization rate was 67% and 44.3% respectively, and the pregnancy rate/OPU 23% and 9%, respectively. The pregnancy rate/transfer was 28.8% and 12.2% respectively, and the implantation rate/transferred embryo 9.5% and 4.2%. In the human sperm survival assay, the vitality and residual motility after 24 hours of incubation were significantly lower in medium B. In conclusion, UltroSer G successfully sustained the development in vitro of mouse embyros. However in human, it reduced sperm survival, oocyte fertilization, and embryo viability.