Fertilization, embryo quality, and cryosurvival in in vitro fertilization and intracytoplasmic sperm injection cycles

Failed sperm retrieval from severely oligospermic or non-obstructive azoospermic patients on oocyte retrieval day: Emergent oocyte cryopreservation is a feasible strategy

Purpose

Unexpected sperm retrieval failure on the day of oocyte retrieval is not common but frequently happened in patients with severe oligospermia or non-obstructive azoospermia(NOA). Oocyte cryopreservation is a common strategy after failed collection of sperm when concurrent ovarian stimulation is underwent. However, the use of oocyte vitrification in such male-infertility cases remains unclear.

Objective

To investigate the outcomes of emergent oocyte cryopreservation after failed sperm retrieval from severe oligospermic or non-obstructive azoospermic (NOA) patients on oocyte retrieval day.

Methods

Design: Retrospective cohort study

Setting: Academic fertility center at Lee Women's Hospital, Taiwan, between March 2015 and August 2017.

Patients: For 203 couples with NOA(n = 200) or severe oligospermia(n = 3), testicular spermatozoa (n = 67 cycles) or frozen donor sperm (n = 209 cycles) were injected into fresh or frozen-thawed oocytes via 276 intracytoplasmic sperm injection (ICSI) cycles.

Main Outcome Measures: Clinical pregnancy and live-birth rates (LBRs).

Results

In the 67 cycles involving the use of fresh testicular spermatozoa, no significant differences were observed between fresh and warmed oocytes with respect to the fertilization rates (69.2% vs. 74.1%; p = 0.27), number of Day-3 embryos (8.6±4.4 vs. 6.4±3.4; p = 0.08), number of good-quality Day-3 embryos (4.5±3.9vs. 4.7±3.0; p = 0.45), implantation rates (29.1% vs. 17.8%; p = 0.21), clinical pregnancy rates (36.4% vs. 26.8.0%; p = 0.81), live birth rates (36.4% vs. 14.3%; p = 0.46), or perinatal outcomes. In the 209 cycles involving the use of frozen donor sperm, no significant differences were seen between the two groups, except that the mean birth weights were significantly lower with fresh oocyte pregnancies than with warmed oocytes (2952±196 gm vs 2643±700 gm; p = 0.006).

Conclusions

Emergent oocyte cryopreservation is a feasible strategy to manage unexpected sperm retrieval failure from severe oligospermic or NOA patients on the oocyte retrieval day. There is no detrimental effect on the live birth rate when testicular spermatozoa or frozen donor sperm are injected into the thawed oocytes compared with fresh oocytes.

Severe oligoasthenoteratozoospermias, secretory and obstructive azoospermias: motility as a criterion of sperm viability

PURPOSE

Comparison of pregnancy rates in cases of Secretory Azoospermias (SA), Obstructive Azoospermias (OA) and severe Oligoasthenoteratozoospermias (OATZ). Evaluation of sperm motility as a quality criterion.

METHODS

In SA cases (n = 35), 9 samples were cryopreserved. In OA cases (epididymal aspiration: n = 91; testicular biopsy: n = 206), all samples were cryopreserved. 596 OATZ ejaculates were included.

RESULTS

In SA cases, 2 pregnancies were achieved from 9 ICSI cycles. In OA, motile sperm rates were higher in testicular biopsies. After thawing sperm motility was not different between testicular and epididymal origin. 2 pregnancies were achieved with immotile testicular sperm after thawing, but none with immotile epididymal sperm. In OATZ cases, one pregnancy was obtained from the 9 cryopreserved ejaculates and 35.3% with fresh motile sperm.

CONCLUSIONS

In SA cases, the use of donor sperm is recommended due to the lower pregnancy rate achieved. Motility, before and after cryopreservation, as a criterion of sperm viability is discussed and its use should be reconsidered in some cases.

Elevated incidence of chromosomally chaotic embryos among frozen-thawed preimplantation embryos

OBJECTIVE

The aim of the study was to evaluate the effect of cryopreservation on the formation of chromosomal abnormalities in human preimplantation embryos.

STUDY DESIGN

The chromosomal constitutions of cleavage stage embryos (n = 61) were assessed using fluorescent in situ hybridisation (FISH) technique, applying probes for chromosomes 13, 16, 18, 21, X and Y. Study group embryos frozen at zygote or two-cell stage (n = 29) were cultured in vitro post-thawing until they reached four- to six-cell stage, after which their chromosomal constitutions were assessed. Control group embryos frozen at four- to six-cell stage (n = 32) were analysed immediately after thawing in order to exclude any post-thaw effect. The proportions of genetically normal and abnormal embryos were compared between study and control group.

RESULTS

The proportions of normal, aneuploid and mosaic embryos were similar in both groups. However, significantly (P < 0.05) higher proportion of chaotic embryos in study (24.1%) compared to control group (6.3%) was observed.

CONCLUSION

The elevated level of chromosomally chaotic embryos among embryos that had undergone cellular division after thawing as compared to embryos analysed immediately after thawing indicates a potential negative impact of cryopreservation on the formation of chromosomal abnormalities in preimplantation embryos.

Embryo freezing after intracytoplasmic sperm injection

This study reports on the safety and efficiency of the cryopreservation of human embryos obtained after intracytoplasmic sperm injection. For this, we evaluated the morphological survival, the capacity of the surviving embryo to develop further in vitro and in vivo. After freezing-thawing embryos obtained after ICSI, 40% of the embryos do not survive the cryopreservation procedure. After selective transfer of further cleaving frozen-thawed embryos, pregnancy loss was 31% (subclinical pregnancy rate of 13% and miscarriage rate of 18%). As a result the livebirth rate per transferred embryos and per thawed embryo was 7 and 3% respectively. Obstetric outcome as well as further follow-up of the children born indicate that cryopreservation of ICSI embryos is a safe procedure, long term follow-up of the children born however is still warranted.

New concepts in superovulation strategies for assisted conception treatments

Controlled ovarian stimulation for in-vitro fertilization treatment using preparations that contain follicle-stimulating hormone has been routinely performed since the 1980s. The early preparations were urinary human menopausal gonadotrophins, containing follicle-stimulating hormone and luteinizing hormone. In the early 1990s, highly purified follicle-stimulating hormone preparations were introduced because of a desire to provide drugs for subcutaneous administration with a lower risk of allergic reactions. Intensive research resulted in the discovery of recombinant follicle-stimulating hormone, which is more potent that the highly purified follicle-stimulating hormone, resulting in significantly higher clinical pregnancy rates. The two recombinant follicle-stimulating hormone preparations available appear to be equally effective and provide comparable results. Gonadotrophin-releasing hormone antagonists, which have recently been introduced, appear to be effective in preventing a premature rise in luteinizing hormone during ovarian stimulation for in-vitro fertilization, as well as improved response to lower doses of gonadotrophins. It is envisaged that the availability of recombinant gonadotrophins and gonadotrophin-releasing hormone antagonists will ultimately lead to shorter, cheaper and safer treatments, using reduced dosages.

Intracytoplasmic sperm injection increases embryo fragmentation without affecting clinical outcome

PURPOSE

To examine the effect of intracytoplasmic sperm injection (ICSI) on embryo fragmentation and implantation rates in those embryos chosen for transfer compared to conventional in vitro fertilization (IVF).

METHODS

We compared 253 infertility patients (71 ICSI and 182 IVF) with respect to age, semen analysis, number of embryos transferred, embryo fragmentation, implantation rate, and pregnancy rate. Embryo fragmentation was determined by one observer at the same laboratory over the entire study period.

RESULTS

A statistically significant difference was observed in mean embryo grade between IVF (2.2 +/- 0.84) and ICSI (2.5 +/- 0.77), P = 0.01. Additionally, the IVF patients had significantly more nonfragmented (grade I) embryos compared to the ICSI group, P < 0.01.

CONCLUSIONS

These data suggest that ICSI, irrespective of semen parameters, may increase embryo fragmentation and produce fewer nonfragmented grade I embryos while maintaining implantation and pregnancy rates similar to conventional IVF.

Comparison of two recombinant follicle-stimulating hormone preparations in in-vitro fertilization: a randomized clinical study

A randomized comparison of two recombinant human follicle-stimulating hormone (recFSH) preparations (Gonal-F and Puregon) in ovarian stimulation for in-vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) was carried out at the Infertility Clinic of the Family Federation of Finland. A total of 348 women (aged 22-43 years) suffering from infertility due to miscellaneous causes was recruited. Of these, 344 underwent stimulation using equal starting doses (150 IU/day: Gonal-F n = 164, Puregon n = 158 or 300 IU/day: Gonal-F n = 8, Puregon n = 14) after down-regulation with intranasal buserelin from the mid-luteal phase. Similar clinical pregnancy rates were achieved with both preparations; 33.5% per cycle and 37.4% per embryo transfer (24.5% one-embryo and 75.5% two-embryo transfers, n = 147) with Gonal-F (150 IU/day) and 32.9% per cycle and 36.4% per embryo transfer (30.1% one-embryo and 69.9% two-embryo transfers, n = 145) with Puregon (150 IU/day). The ongoing cumulative pregnancy rates after frozen-thawed embryo transfer were 35.4% with Gonal-F and 37.7% with Puregon. Six cycles were cancelled because of a low response (three in each group). Similar numbers of oocytes were obtained in both groups; 13.0 with 150 IU/day and 6.1 with 300 IU/day Gonal-F, and 12.4 with 150 IU/day and 7.1 with 300 IU/day Puregon. The fertilization and cleavage rates and the incidence of moderate or severe ovarian hyperstimulation syndrome (Gonal-F, 2.0% and Puregon, 0.7%) were also similar. Gonal-F and Puregon were equally and highly effective in stimulation for IVF and ICSI.