Cryopreserved/thawed semen for in vitro fertilization: results from fertile donors and infertile patients**Presented in part at the 14th Annual Meeting of the American Society of Andrology, New Orleans, Louisiana, April 13 to 16, 1989

Optimization of IVF pregnancy outcomes with donor spermatozoa

PURPOSE

To identify risk factors for suboptimal IVF outcomes using insemination with donor spermatozoa and to define a lower threshold that may signal a conversion to fertilization by ICSI rather than insemination.

METHOD

Retrospective, age-matched, case-control study of women undergoing non-donor oocyte IVF cycles using either freshly ejaculated (N=138) or cryopreserved donor spermatozoa (N=69). Associations between method of fertilization, semen sample parameters, and pregnancy rates were analyzed.

RESULTS

In vitro fertilization of oocytes with donor spermatozoa by insemination results in equivalent fertilization and pregnancy rates compared to those of freshly ejaculated spermatozoa from men with normal semen analyses when the post-processing motility is greater than or equal to 88%. IVF by insemination with donor spermatozoa when the post-processing motility is less than 88% is associated with a 5-fold reduction in pregnancy rates when compared to those of donor spermatozoa above this motility threshold. When the post-processing donor spermatozoa motility is low, fertilization by ICSI is associated with significantly higher pregnancy rates compared to those of insemination.

CONCLUSION

While ICSI does not need to be categorically instituted when using donor spermatozoa in IVF, patients should be counseled that conversion from insemination to ICSI may be recommended based on low post-processing motility.

Efficacy of IVF using frozen donor semen in cases of previously failed DI cycles compared with tubal infertility: a cohort study

A cohort follow-up study was designed to compare the efficacy of IVF using frozen donor semen (IVF-D) following previously failed DI cycles (unexplained female infertility) and direct IVF-D treatment because of tubal infertility (control group). The cohort comprised 189 couples initiating IVF-D after previously failed DI cycles (n = 126) or directly (n = 63). Couples were followed until completion (success or drop-out for personal or medical reasons). Live births and drop-out were expressed both as rate per cycle and crude cumulative rate. Characteristics of IVF-D cycles were similar between the two groups. Moreover, overall outcome was also similar in terms of crude cumulative live birth rate (54.0 versus 57.1% for failed DI cycles and tubal infertility groups respectively). This is the first report on crude cumulative live birth rate based on a cohort follow-up study in unexplained previously failed DI cycles and tubal infertility. Previously failed DI cycles did not impair the chances of achieving a successful pregnancy using IVF-D in this series. Slight oocyte dysfunction, which might underlie the failure of DI cycles, might be overcome using IVF-D.

Cohort follow-up of couples with primary infertility in an ART programme using frozen donor semen

BACKGROUND

This study was designed to determine the crude cumulative live-birth rates in a cohort initiating frozen donor semen treatment until completion.

METHODS

This cohort study included 588 couples with primary infertility in one University Hospital centre. The treatment sequence involved first artificial insemination (AID) followed by IVF if necessary (IVF-D). Live birth, drop-out for personal or medical reasons and recourse to IVF-D were recorded for all patients. Live births and drop-out were expressed both as rates per cycle and crude cumulative rates.

RESULTS

At the completion of AID and IVF-D cycles, 406 couples in the cohort (69%) achieved a live-birth and 182 couples (31%) discontinued treatment. In most cases, couples stopped treatment for personal reasons (74%) whereas fewer couples were denied further treatment for medical reasons (26%).

CONCLUSIONS

This is the first report on the crude cumulative live-birth rate in a cohort after AID and IVF-D cycles. Although calculation based on crude cumulative live-birth rate shows lower results in comparison with life table analysis, this method allows patients to obtain an insight into their actual chances of achieving a successful pregnancy.

Cryopreservation-thawing of fractionated human spermatozoa and plasma membrane translocation of phosphatidylserine

OBJECTIVE(S)

[1] To evaluate sperm membrane damage during cryopreservation-thawing by the assessment of phosphatidylserine (PS) translocation and [2] to examine the relationship between reactive oxygen species (ROS) and cryopreservation-related alterations.

DESIGN

Prospective cohort study.

SETTING

University-based center.

PATIENT(S)

Men consulting for infertility and fertile donors (controls).

INTERVENTION(S)

Semen processing was performed by density gradient separation followed by cryopreservation and thawing.

MAIN OUTCOME MEASURE(S)

Membrane PS translocation was evaluated with annexin V binding, generation of ROS was detected by chemiluminescence, and motion parameters were assessed by computer analysis.

RESULT(S)

Annexin V binding was detected in the prefreeze fractions with high and low sperm motility. In the patient group, there were significantly higher postthaw levels of annexin V binding in both fractions when compared with prefreezing values. However, such induction of PS translocation was significantly higher in the fractions with high sperm motility. Significantly higher ROS levels were detected in prefreeze samples of the fractions with low sperm motility.

CONCLUSION(S)

In the population of men studied, [1] cryopreservation-thawing was associated with induction of membrane PS translocation; [2] postthaw ROS levels were lower than before freezing; and [3] neither annexin V binding results nor the generation of ROS were able to accurately predict sperm cryosurvival rates.

Assessment of sperm cryodamage and strategies to improve outcome

Sperm cryopreservation still represents a valuable clinical aid in the management of infertility. Its current principal indications include (1) donor sperm insemination; (2) freezing before cancer therapy to maintain reproductive capacity; (3) patient's convenience; and (4) because of the outstanding success with ICSI, even patients with different degrees of oligo-asthenoteratozoospermia can now be offered the use of frozen/thawed sperm for oocyte micromanipulation. Although sperm cryopreservation/thawing and results of insemination and IVF have been consistently good using donor semen, results of infertile men (with or without various degrees of oligoasthenoteratozoospermia) have yielded remarkably lower rates of survival and pregnancy. Freezing/thawing techniques have not been subjected to major changes in the last years, Furthermore, the exact nature of sperm cryodamage still remains to be elucidated. Various aspects of sperm freezing are revisited here (1) development of new technical approaches for cryopreservation; (2) analysis of the stimulatory effect of putative cryoprotectant additives; (3) the use of intrauterine insemination-ready processed samples; and (4) selection and optimization of end-points for analysis of cryodamage. It is expected that advances in such areas will improve significantly the cryopreservation/thawing outcome particularly as related to semen samples of subfertile men.

Semen treatment with progesterone and/or acetyl-L-carnitine does not improve sperm motility or membrane damage after cryopreservation-thawing

OBJECTIVE

To assess the effects of progesterone and acetyl-L-carnitine used before semen cryopreservation-thawing on sperm motility parameters and plasma membrane integrity.

DESIGN

Prospective cohort study.

SETTING

Academic tertiary center.

PATIENT(S)

Subfertile men undergoing semen evaluation.

INTERVENTION(S)

Before cryopreservation, spermatozoa were incubated with water-soluble progesterone (1 and 10 microM), acetyl-L-carnitine (2.5, 5, 10, and 20 mM), or both (progesterone, 1 microM; and acetyl-L-carnitine, 5 mM).

MAIN OUTCOME MEASURE(S)

Postthaw change of motility parameters (computer-assisted measurements) and vitality-membrane integrity (examined with eosin-Y staining and annexin V-Cy3 binding assay).

RESULT(S)

There were no statistically significant differences between control samples and samples treated with progesterone and/or acetyl-L-carnitine for cryosurvival rate, motility parameters, or membrane integrity. The percentages of postthaw cells identified as live showed significantly different results with use of the eosin-Y staining and annexin V binding assay.

CONCLUSION(S)

Neither progesterone nor acetyl-L-carnitine seemed to prevent cryodamage assessed by motility changes or membrane integrity in human spermatozoa of subfertile men. Annexin V binding, a reflection of membrane translocation of phosphatidylserine, provided more distinct information about postfreezing membrane integrity changes than eosin-Y staining.

Plasma membrane integrity of cryopreserved human sperm: an investigation of the results of the hypoosmotic swelling test, the water test, and eosin-Y staining

OBJECTIVE

[1] To examine the relationship between sperm membrane integrity and motion parameters before and after cryopreservation; [2] to determine the capacity of the membrane integrity tests to predict the outcome of cryopreservation in fertile and infertile men; and [3] to examine the degree of agreement between tail and head membrane integrity of testicular and ejaculated immotile sperm cryopreserved for intracytoplasmic sperm injection.

DESIGN

Prospective study.

SETTING

Academic tertiary care institution.

PATIENT(S)

Fertile donors and normozoospermic oligozoospermic, and asthenozoospermic subfertile men.

INTERVENTION(S)

Semen samples were cryopreserved and thawed for analysis.

MAIN OUTCOME MEASURE(S)

Sperm membrane integrity and computer-assisted motion parameters.

RESULT(S)

The hypoosmotic swelling test and water test had a significant and positive correlation in the fresh and cryopreserved ejaculates of all groups. The results of the hypoosmotic swelling test correlated positively with the percent motility in the fresh ejaculates of fertile and subfertile men. None of the membrane integrity tests correlated with the cryosurvival rate in any group. In the ejaculated and testicular samples with no postcryopreservation motility, the simultaneous assessment of hypoosmotic swelling test and eosin showed that of 33% sperm exhibiting coiling with the hypoosmotic swelling test, only 9% were eosin negative, whereas 24% were eosin positive.

CONCLUSION(S)

[1] The water test may be a simpler replacement for the hypoosmotic swelling test; [2] none of the membrane integrity tests predicted sperm motility after cryopreservation; and [3] there was a high degree of disagreement between the hypoosmotic swelling test and eosin in the samples with no postcryopreservation motility.

Fresh and frozen epididymal sperm yield comparable pregnancy rates for intracytoplasmic sperm injection

To determine if the use of fresh epididymal sperm is superior to frozen-thawed epididymal sperm for intracytoplasmic sperm injection, the authors reviewed the charts on all couples undergoing intracytoplasmic sperm injection at an academic center, using microsurgically aspirated epididymal sperm. Forty-nine couples undergoing intracytoplasmic sperm injection for male factor infertility, due to congenital absence of vas deferens or irreparable post-testicular obstruction were studied. The following parameters were measured: (1) fertilization rate per oocyte injected (two pronuclei at 24 h), (2) chemical pregnancy rate (two consecutively elevated serum b-hCG levels, and (3) clinical pregnancy rate (sonographic identification of fetal heart rate). Fertilization rates were 51 and 41%, chemical pregnancy rates were 27 and 30%, and clinical pregnancy rates were 19 and 27% in the fresh epididymal compared to the frozen epididymal sperm. This study shows no significant difference in outcomes using fresh or frozen epididymal sperm for intracytoplasmic sperm injection. Frozen-thawed sperm guarantees availability of sperm prior to oocyte retrieval.

In vitro fertilizing capacity of frozen-thawed boar semen

We describe a porcine semen cryopreservation technique and assess the in vitro fertilizing capacity of the frozen-thawed spermatozoa. The thawed spermatozoa did not lose the physiological properties of motility, viability, and acrosome reaction or capacity to fertilize in vitro. Immediately after thawing, the spermatozoa showed 51% mean motility, 60% viability, and 5% induced acrosome reaction. After 2.5 h of incubation in TALP medium, the spermatozoa exhibited 61% motility, 63% viability and 40% induced acrosome reaction. The average in vitro fertilization capacity of thawed spermatozoa was 68% compared with that of spermatozoa from fresh semen (85%). The percentage of polyspermy was highly variable, with frozen-thawed samples ranging from 0 to 28% and fresh samples from 0 to 30%. The results obtained with frozen semen from 5 boars of different breeds did not show considerable variation. This suggests that the freezing-thawing technique is reproducible and adequate for in vitro fertilization.

Investigation of some biochemical and functional effects of cryopreservation of human spermatozoa using an automated freezing-quick-thawing method

The objective of the present studies was to assess the functional integrity of the sperm plasma membrane and metabolic and motility characteristics of the recovered motile fraction of human spermatozoa subjected to an automated freezing/quick-thawing method. Sperm membrane features examined included progesterone-induced changes in intracellular levels of calcium ([Ca2+]i), as measured by the fluorescent fura-2 indicator, and the tight binding of spermatozoa to homologous zonae pellucidae as assessed by the hemizona assay (HZA). Basal [Ca2+]i intracellular adenosine triphosphate (ATP) and adenosine diphosphate (ADP) levels determined using chemiluminescence with luciferin-luciferase, and motility parameters determined using a computer-aided semen analyser (CASA) were studied concomitantly as an expression of metabolic/functional status. Ejaculates from fertile men (donors) were evaluated after swim-up separation of the motile fraction in both fresh and cryopreserved-thawed samples, and fractions of each ejaculate (fresh and frozen-thawed) were subjected to parallel measurements of the same parameters at the same time frame. Basal and progesterone-induced increase in [Ca2+]i, and ATP levels (up to 24 h) were similar in fresh and frozen-thawed samples. HZA results showed a modest (26%) although significant (p = 0.008) decrease in binding in frozen-thawed samples. The ratios of ATP/ADP in fresh and frozen-thawed samples were also found to be similar. Although post-thaw sperm motility was significantly lower than that of the fresh samples, comparison of the results indicated that the method was capable of preserving > 65% of motile spermatozoa in almost all of the samples cryopreserved. Additionally, the swim-up rescued a motile fraction in the frozen-thawed samples that was not significantly impaired with regard to motility, mean linear velocity or linearity as compared to the fresh fractions in the first 4 h. Our results show that this automated freezing-quick-thawing method results in a small reduction in sperm-zona binding capacity, and that the time-dependent decline in motility parameters observed for both fresh and cryopreserved-thawed samples cannot be related to ATP deficiency under the conditions of our experiments. These in-vitro results are coincident with the maintenance of fertilizing capacity for donor spermatozoa in the in-vitro fertilization (IVF) setting.

Identification of cyclo(His-Pro)-like immunoreactivity in human follicular fluid: correlation with steroid and peptide hormones

OBJECTIVE

The purpose of this study was to evaluate human follicular fluid (FF) for the presence of cyclo(His-Pro)-like immunoreactivity (CHP-LI). After verifying its presence, we quantitated the levels and investigated correlations with other follicular parameters, including hormone levels.

METHODS

Follicular fluid was collected from female volunteers undergoing controlled ovarian hyperstimulation. Fluid was collected by follicular puncture, either transvaginally (in vitro fertilization) or laparoscopically (gamete intrafallopian transfer) at the time of oocyte retrieval (N = 137). Follicular size was determined ultrasonographically. Assays for steroid and peptide hormones were determined with commercially available radioimmunoassay kits. CHP-LI was measured using a previously reported assay; parallel dilution curves and column chromatography aided in immunoidentity.

RESULTS

The mean FF CHP-LI concentration (13.10 +/- 1.83 nmol/L, N = 137) was greater than the corresponding serum values (9.42 +/- 2.45 nmol/L; N = 21) (P < .05). Large follicles (20 mm or greater; 14.45 +/- 1.74 nmol/L) contained significantly more CHP-LI than either medium follicles (16-19 mm; 11.51 +/- 1.88 nmol/L) or small follicles (15 mm or smaller; 10.83 +/- 2.12 nmol/L) (P < .05). Positive correlations were found between FF CHP-LI values and corresponding FF progesterone and prolactin concentrations (r = 0.67 and 0.62, respectively; P < .05).

CONCLUSION

Mean CHP-LI levels in the FF are greater than those in the corresponding serum. We suggest that the neuropeptide may be originating from either peptidase cleavage of precursor peptides or from granulosa cell production.

Impact of cryopreservation on spermatozoa from infertile men: implications for artificial insemination

The objective of this study was to evaluate the effect of cryopreservation-thawing on the quality of sperm from men with subfertile semen parameters. Twenty-seven patients with teratozoospermia, six of whom also had asthenozoospermia, were studied and their sperm parameters were compared to those of fertile donors (n = 71) in their fresh, post-thaw, and washed samples. After thawing, the percentage decrease in motility was significantly greater in patients than in donors, but the motility yield (post-thaw motility/prethaw motility) reached an average of 58% in the patient group vs. 68% in the donors (p = .02). No single characteristic of the fresh samples from patients or donors could significantly predict post-thaw outcome. For the patient group, however, multiple regression analysis provided a cutoff sperm concentration (50 x 10(6)/mL) and motility (40%) below which a very poor post-thaw recovery was obtained. The frozen-thawed-washed specimens had significantly higher velocity than the frozen-thawed samples, both in patients and donors. The results suggest that some patients with teratoasthenozoospermia yield acceptable sperm parameters after freezing-thawing-washing, and therefore these ejaculates could be used individually (or pooled) in artificial insemination.

Effect of natural antioxidants tocopherol and ascorbic acids in maintenance of sperm activity during freeze-thaw process

Excessive generation of reactive oxygen species and increased peroxidation of the phospholipids in the membrane is proposed as a biochemical basis for the reduced activity of spermatozoa in cryopreserved semen. The possible role of alpha-tocopherol (VE) and ascorbic acid (VC) in improving the quality of frozen semen was investigated. Semen samples were divided into aliquots and frozen in freezing media with and without VC or VE. Sperm parameters, including motility after thawing and also at 2 h, % grade A motility (rapid and linear forward progression), and hypoosmotic swelling (HOS) scores, were measured in all samples. Vitamin C did not result in any improvement in sperm parameters studies. Vitamin E improved the post-thaw motility minimally. This improvement, although statistically significant, was actually very small. There were, however, wide variations between the samples. The motility improvement was considered in 5 of 12 samples, and HOS improved in some of the samples tested with VE. Future studies are needed to determine if these antioxidants can produce a consistent improvement in some individuals rather than help the majority of patients.

Cryopreservation of the occasionally improved semen samples for intrauterine insemination: a new approach in the treatment of idiopathic male infertility

OBJECTIVE

To assess the value of treating idiopathic male infertility by intrauterine insemination (IUI) of the occasionally improved cryopreserved semen.

DESIGN

Two groups of idiopathic oligospermic patients were chosen at random and treated by IUI using processed fresh semen in group A and the best available cryopreserved semen samples pooled with fresh samples in group B.

SETTING

Egyptian IVF-ET Centre, Maadi, CAiro, Egypt.

PATIENTS, PARTICIPANTS

One hundred fifty infertile couples because of idiopathic oligoasthenospermia.

INTERVENTION

Intrauterine insemination.

MAIN OUTCOME MEASURE

The pregnancy rate was evaluated after an average of three treatment cycles.

RESULTS

The pregnancy rate (PR) was significantly higher in group B when compared with group A. The improvement in the PR was highly significant in the subgroup of patients for whom reasonable semen samples could be collected and cryopreserved.

CONCLUSIONS

Our study indicates that IUI with fresh semen pooled with cryopreserved occasionally improved semen samples for the treatment of oligoasthenospermia results in an improved PR.

Fresh versus frozen thawed semen for initial and late insemination in IVF cycles

Frozen thawed semen has been associated with reduced semen quality and as a result diminished pregnancy rates. In vitro fertilization (IVF) can supply the true measure of the functional fertilizing capacity of fresh versus frozen-thawed semen. One hundred and six patients in an IVF program who underwent donor insemination were divided into two groups. Group I included 51 women in whom initial insemination with donor fresh or frozen semen was performed. They were compared to 65 group II women in whom late insemination with donor fresh or frozen semen was performed after initial insemination with husband semen had failed to fertilize the eggs. There was no statistically significant difference between groups I and II on initial insemination; however, statistically significant difference in fertilization (P less than 0.006) and pregnancy rates (P less than 0.001) between the two groups were achieved when late insemination was carried out. Consequently, we prefer initial insemination with frozen-thawed donor semen in cases indicated.