Half-dose depot triptorelin in pituitary suppression for multiple ovarian stimulation in assisted reproduction technology: a randomized study

BACKGROUND: Pituitary suppression by depot GnRH agonist may be excessive for ovarian stimulation in assisted reproduction technology. This study compares the efficacy of standard and half-dose depot triptorelin in a long protocol. METHODS: A total of 180 patients were randomized into two groups using sealed envelopes. Pituitary desensitization was obtained in group 1 (90 patients) with half-dose (1.87 mg) triptorelin depot in the mid-luteal phase of their menstrual cycle, and in group 2 (90 patients) with full-dose (3.75 mg) triptorelin. RESULTS: There was no premature LH surge, with LH levels being lower in the full-dose group (1.04+/-0.05 versus 0.7+/-0.06 IU/l on the day of hCG). The number of FSH ampoules used was lower in group 1 (42+/-2 versus 59+/-3). The numbers of mature oocytes (10.1+/-0.54 versus 7.4+/-0.55), of fertilized oocytes (8.24+/-0.35 versus 6.34+/-0.37) and of embryos (7.8+/-0.36 versus 5.9+/-0.37) were significantly higher in group 1. No significant differences were found in pregnancy (38.8 versus 25.3%), implantation (22.6 versus 13.8%) or abortion (6.1 versus 5.0%) rates. Cumulative pregnancy (fresh plus frozen embryo transfers: 56.8 versus 35.4%) rate was significantly higher in group 1. CONCLUSION: A half-dose of depot triptorelin can be successfully used in ovarian stimulation for IVF and produce a higher number of good quality embryos with a good chance of implantation.     

Morphokinetics of embryos developed from oocytes matured in vitro

Purpose

In in vitro maturation (IVM) cycles primed with human chorionic gonadotropin (hCG), both immature and mature oocytes are retrieved from antral follicles sized 8–12 mm. Using time-lapse microscopy, we compared the morphokinetic behavior of embryos developed from oocytes matured in vivo and in vitro, testing the hypothesis that IVM affects preimplantation development. Furthermore, we extended the morphokinetic analysis of these embryos by a comparison with embryos obtained in stimulated assisted reproduction technology (ART) cycles.

Methods

In IVM cycles primed with follicle-stimulating hormone (FSH)/hCG, prior to sperm microinjection, oocytes surrounded by an expanded cumulus at retrieval and presumably mature (EC-MII) were incubated for 6 h, while immature oocytes enclosed in a compact cumulus (CC) were matured in vitro for 30 h. The morphokinetics of embryos selected for transfer or cryopreservation, derived from EC-MII and CC oocytes, were comparatively and retrospectively analyzed in terms of cleavage times (t2, t3, t4, t5, and t8) and intervals (cc2, cc3, s2, s3). For further comparison, the morphokinetics of embryos selected for transfer or cryopreservation (ICSI) or giving rise to ongoing pregnancies (model) in stimulated ART cycles was also assessed.

Results

The morphokinetic behavior of EC-MII and CC embryos was entirely comparable, as suggested by the absence of statistical differences in the averages of all cleavage times and intervals. Almost all cleavage and interval times were also similar between EC-MII, CC, ICSI, and model groups, with the exception of t4 and s2, which were delayed and longer, respectively, in embryos generated in IVM cycles (EC-MII and CC).

Conclusions

These findings do not support the hypothesis that maturation in vitro affects embryo morphokinetics, while they suggest only marginal differences in the morphokinetics of embryos developed from oocytes matured in vivo and in vitro in IVM cycles and embryos developed from mature oocytes recovered in stimulated cycles.

     

Differential sucrose concentration during dehydration (0.2 mol/l) and rehydration (0.3 mol/l) increases the implantation rate of frozen human oocytes

Novel protocols have increased survival and fertilization rates of cryopreserved oocytes. Nevertheless, in most cases clinical experiences have been disappointing or contradictory. Human oocytes of 141 patients were cryopreserved using a modified slow-cooling protocol involving 1.5 mol/l propane-1,2-diol (PrOH) and 0.2 mol/l sucrose during dehydration, while rehydration was conducted applying decreasing concentrations of PrOH and 0.3 mol/l sucrose. One thousand and eighty-three oocytes were frozen and 403 were thawed, with a survival rate of 75.9%. Among the 306 surviving oocytes, 252 were microinjected and 192 (76.2%) showed two pronuclei. One hundred and eighty zygotes (93.8%) cleaved. The proportion of good quality embryos (grade I and II) was 86.2%. All embryos were transferred and 17 clinical pregnancies were obtained. Pregnancy rates were 21.3% per transfer, 21.8% per patient, and 18.9% per thawing cycle. The implantation rate was 13.5% while the miscarriage rate was 11.8%. To date, four babies have been delivered, while the remaining pregnancies are ongoing. Increased oocyte survival rates can be achieved by moderately high sucrose concentrations in the freezing and thawing solutions. This also ensures elevated success rates in terms of fertilization, embryo development and clinical outcome.     

Cryopreservation of human oocytes

Cryopreservation is a well established technique by which preimplantation stage embryos can be stored for later use. However, it would be preferable to cryopreserve unfertilized oocytes to overcome the problems related to the ethical and legal status of the embryo. This procedure has been successful in mice, but attempts to extend this approach to other species have been less successful. In human in vitro fertilization (IVF) in particular, very few live births have been reported after the cryopreservation of oocytes. The reason for this lack of success is unclear. The widespread contention that compromised oocyte viability originates principally from damage to the meiotic spindle induced by cryopreservation conditions is unproven. The treatment of large groups of women has shown that pregnancies derived from stored oocytes can be achieved in a reproducible fashion, although success rates are still lower than those derived from frozen embryos. To date, human oocytes have been stored largely by applying methods originally designed for cleaving embryos. Therefore, it is reasonable to envisage that appropriate modification of current freezing techniques will increase survival rates and make oocyte storage an important option in IVF treatment.     

Theoretical and experimental basis of slow freezing

In human IVF, cryopreservation of oocytes has become an alternative to embryo storage. It has also shown enormous potential for oocyte donation, fertility preservation and animal biotechnology. Mouse oocytes have represented the elective model to develop oocyte cryopreservation in the human and over several decades their use has made possible the development of theoretical and empirical approaches. Progress in vitrification has overshadowed slow freezing to such an extent that it has been suggested that vitrification could soon become the exclusive cryopreservation choice in human IVF. However, recent studies have clearly indicated that human embryo slow freezing, a practice considered well established for decades, can be significantly improved by a simple empirical approach. Alternatively, recent and more advanced theoretical models can predict oocyte responses to the diverse factors characterizing an entire slow-freezing procedure, offering a global method for the improvement of current protocols. This gives credit to the notion that oocyte slow freezing still has considerable margins for improvement.     

Polar body morphology and spindle imaging as predictors of oocyte quality

It has been suggested that first polar body (PBI) morphology reflects oocyte competence. Oocytes with an intact normal-sized PBI have been described as generating better day 2 embryos, higher blastocyst yield, and increased pregnancy and implantation rates. In other studies, PBI morphology was found to be unrelated to fertilization rate, embryo quality, and blastocyst formation. In a prospective analysis, the predictive value of the PBI was investigated by comparing the development of oocytes retrieved from intracytoplasmic sperm injection patients and displaying different PBI morphology, classified according to the following characteristics: normal size and smooth surface (I), fragmented (II), rough surface (III), or large size (IV). Fertilization rates were 59, 57, 64 and 60% respectively. No significant differences were found between the various groups. The proportions of high quality (grade A) day 2 embryos were also comparable among groups I-III (14, 12 and 17% respectively), while the low number of grade A embryos in group IV (two embryos) did not allow comparison with the other classes. These data do not suggest that PBI selection can contribute to identification of embryos with high developmental ability. In order to establish alternative criteria for oocyte selection, a metaphase II (MII) spindle analysis was also conducted via Polscope. In oocytes of patients of different age, spindle retardance (which reflects the high order and density of microtubules) was compared with parameters of embryo development. In aged patients, a trend was observed between low retardance and poor embryo quality, although in general the association between retardance and oocyte developmental performance did not reach statistical significance.     

Cumulus cell-oocyte complexes retrieved from antral follicles in IVM cycles: relationship between COCs morphology, gonadotropin priming and clinical outcome

Purpose

To assess retrospectively the developmental potential of different types of cumulus cell-oocyte complexes (COCs) derived from IVM cycles.

Methods

IVM cycles were performed in natural cycles or after HCG, FSH, or FSH/HCG priming. COCs recovered were morphologically characterized in different types: compact (CC) or expanded (EC) cumulus mass but including an immature oocyte, and expanded cumulus mass enclosing a mature oocyte (EC-MII). Embryo developmental competence was investigated analysing exclusively cycles in which all transferred embryos derived from the same COC category.

Results

Fertilization rates did not differ significantly. Significant differences in pregnancy rates (14.5 %, 10.0 % and 27.6 % in the CC, EC, and EC-MII categories, respectively) were observed. Likewise, significant differences in implantation rates (8.9 %, 6.3 % and 19.1 % in the CC, EC, and EC-MII categories, respectively) were found. Overall, priming with FSH/HCG had a beneficial effect on pregnancy and implantation rates, while no priming or HCG alone generated oocytes with poor competence.

Conclusions

In IVM cycles, morphological evaluation at the time of collection can predict the developmental ability of different COCs. FSH/HGC priming has a positive effect on oocyte competence.     

Retrospective analysis of treatments with recombinant FSH and recombinant LH versus human menopausal gonadotropin in women with reduced ovarian reserve

Purposes

The aim of this study is to determine whether a clinical advantage is gained with use of LH in combination with FSH or as a component of human menopausal gonadotropin (hMG) to achieve optimal ovarian stimulation.

Methods

In this study, we compared retrospectively two regimens, r-FSH/r-LH and hMG, for the treatment of women with reduced ovarian reserve, identified as subjects with antral follicle count (AFC) < 11 and AMH ≤ 1.1 ng/ml.

Results

Overall, the clinical pregnancy per started cycle was higher in the r-FSH/r-LH group (12.5 vs. 8.1%, P < 0.02), while implantation (11.1 vs. 9.5%) and miscarriage rates (29.9 vs. 35.9%) were comparable. Data were further analysed performing separate comparisons in subpopulations with different ranges of AFC, i.e. < 4, 4–6 and 7–10. Major differences between the two regimens were observed in women with AFC < 4. In this subpopulation, not only was the clinical pregnancies per started cycle higher in the r-FSH/r-LH group (10.2 vs. 1.5%, P < 0.01), but also implantation was significantly higher (13.0 vs. 2.8%, P < 0.02).

Conclusions

A r-FSH/r-LH regimen appears to be beneficial for the treatment of women with extremely poor ovarian reserve. It should be considered however that, being retrospective, this study is affected by obvious limitations, such as post-treatment patient selection criteria and absence of randomisation.