Human cumulus-free oocyte maturational profile and in vitro developmental potential after stimulation with recombinant versus urinary FSH

Morphological selection of gametes

Methods of selecting gametes before the intracytoplasmic sperm injection (ICSI) technique are of paramount importance, especially where for religious, ethical or legal reasons the production of supernumerary embryos has to be avoided. In these circumstances, in fact, the research has to be focused on the identification of early markers of embryo quality at the oocyte and sperm stage before fertilisation. Oocyte quality can be influenced by several factors such as controlled ovarian hyperstimulation protocols, pharmaceutical preparations and perifollicular vascularisation. Several intracytoplasmic and extracytoplasmic abnormalities have been described, but whether these abnormalities might be predictive of oocyte competence is controversial and the selection methods proposed are still poorly effective. Recently, we have observed that oocyte morphological abnormalities might be indicators of oocyte competence. An abnormal first polar body (but not fragmented), a large perivitelline space, increased cytoplasmic granularity, and the presence of a centrally located granular area seem to have a negative effect on the oocyte potential to fertilise, cleave, and/or develop into a viable embryo. Sperm morphology can be more accurately observed at high magnification using an inverted microscope equipped with Normarski optics (1000x magnification under mineral oil) and a digital system in order to reach a final magnification of approximately 6300x. Single sperm nuclear abnormalities based on strict selection criteria seems to have a clear negative association with ICSI outcome. The possibility of observing the spermatozoa in real time at higher magnification might also be a good opportunity to study the relationship between particular sperm defects and ICSI outcome. In addition to morphology, it has been suggested that spermatozoa selection might be performed on the basis of its biochemical ability to bind to solid hyaluronic acid. However, it must be underlined that prospective randomised studies are necessary to confirm the preliminary results regarding the efficacy of the described criteria proposed, to morphologically select gametes prior to in vitro insemination.

Prolonged HCG action affects angiogenic substances and improves follicular maturation, oocyte quality and fertilization competence in patients with polycystic ovarian syndrome

BACKGROUND

The aim of this study was to determine whether, in polycystic ovarian syndrome (PCOS) patients, HCG action prolonged for 4 h improves the action of angiogenic substances [ovarian renin angiotensin system and vascular endothelial growth factor (VEGF)], and consequently follicular maturation, oocyte quality and oocyte fertilization competence.

METHODS

In this prospective study 20 patients with PCOS undergoing IVF were included. Oocyte retrieval was carried out either 34 or 38 h after HCG administration. Each follicle was analysed for prorenin, active renin, VEGF and estradiol. Oocytes were evaluated for quality (mature, immature, degenerated oocytes), as were the embryos (low or high).

RESULTS

In the HCG +38 h group there were 245 follicles, and in the HCG +34 h group 240 follicles. In the HCG +38 h group, log active renin was lower (2.78 +/- 0.20 versus 2.91 +/- 0.25; P < 0.001) and VEGF higher (2276.0 +/- 790.1 versus 1946.6 +/- 954.5 pg/ml; P < 0.001). The odds ratio for obtaining oocytes from follicles was 1.6 [95% confidence interval (CI) 1.1-2.6; P = 0.02], and for developing high quality embryos 7.6 (95% CI 2.8-20.9; P < 0.001) in favour of the HCG +38 h group.

CONCLUSIONS

Follicular maturation and oocyte quality are related to the intrafollicular influences of active renin and VEGF in a time-dependent manner after HCG administration, whereas fertilization competence is related to VEGF only.

Ten years of Swiss National IVF Register FIVNAT-CH. Are we making progress?

In 2001, analysis of Swiss data collected since 1993 included 1001 treatment cycles with IVF, 2217 treatment cycles with intracytoplasmic sperm injection and 2160 treatment cycles with frozen-thawed embryos or zygotes. IVF cycle number has remained constant over the past 10 years, now representing only 18% of the total. ICSI treatment cycles have plateaued since 2001. Altogether, patients receive 1.56 treatment cycles per year, nearly constant since 1995. Mean maternal age has increased from 33.9 to 35.7 years, while mean number of recovered oocytes has increased by 1.3. Considerable improvement was seen in clinical pregnancy rate after 'fresh' treatment cycles since 2000. Mean number of replaced embryos in 'fresh' treatment cycles has fallen to below 2.5 since 1996, long before the legal imposition of the three-embryo transfer limit in 2001, and is still decreasing without affecting the consistent twin pregnancy rate of 19%. The frequency of ovarian hyperstimulation syndrome has increased three-fold. External audits have reduced the mean number of errors per data file by half, and increased the number of correct files by 20%. Data collected over this 10-year period show that despite the introduction of a restrictive law and increasing mean maternal age, the overall clinical pregnancy rate has continued to improve.