Prediction of in vitro fertilization rates from semen variables

Correlation of post swim-up acrosome index with in-vitro fertilization outcomes

PURPOSE

A prospective study was planned to determine the relationship between post swim-up acrosome index (AI) evaluation and fertilization outcomes in an in vitro fertilization (IVF) program.

MATERIALS AND METHODS

Infertile couples who have applied to IVF were admitted into this study when the male partner's sperm concentration was > 20 x 10(6)/mL and motility > 30%. Pre- and post swim-up semen quality parameters including concentration, motility, sperm morphology and AI were evaluated in a prospective, randomized and blinded fashion. The couples were divided prospectively into 2 groups. In group I (25 couples) 50 000 sperm per oocyte were used for insemination considering post swim-up acrosome index, and in group II (25 couples) 50 000 sperm per oocyte were used for insemination without considering post swim-up acrosome index.

RESULTS

Pre- and post swim-up AI were 30.8 +/- 3.4 and 17.8 +/- 4.5 in group I, and 31.4 +/- 3.6 and 16.3 +/- 4.7 in group II (p > 0.05) respectively. The significant improvement in morphology and motility after double wash swim-up procedure has been observed. However, double wash swim-up procedure could not eliminate head and especially acrosomal defects which would directly effect fertilization capacity in conventional IVF program. In group I, 85.3% of oocytes were fertilized, with a 48% pregnancy rate; in group II, 71.0% of oocytes were fertilized, with a pregnancy rate of 20%. Fertilization and pregnancy rates were significantly different (p < 0.05) between the two groups.

CONCLUSION

We have concluded that it could be useful to consider post swim-up AI of sperm inseminated in conventional IVF cycles, which correlates with high fertilization and pregnancy rates.

The diagnostic significance of the induced acrosome reaction

In trying to discern potential causes of male infertility, little investigation has been done to determine if there is predictive value in assessing acrosome reaction inducibility of human spermatozoa for clinical interpretation and application. The purpose of this review is to outline what is currently known in terms of the diagnostic significance of the induced acrosome reaction and to discuss what might be anticipated for the future. In constructing this review, every effort has been made to provide a comprehensive literature review for the reader and a number of review articles have been cited to serve as sources for additional related material. Regarding the aforementioned, it is essential to qualify that, with the exception of the Section entitled: ‘General characteristics of capacitation and the acrosome reaction’, only characteristics, properties and areas relevant to human spermatozoa will be addressed. Thus, in total, this review will: (1) provide a general description of capacitation and the acrosome reaction; (2) briefly characterize the acrosome and its properties; (3) address the signalling mechanism(s) by which the acrosome reaction occurs; (4) outline various methods for detecting the acrosome reaction; (5) definein vitroculture conditions that facilitate the acrosome reaction; (6) define agents, i.e., biological and chemical, that induce the reaction; (7) discuss the association of the acrosome reaction with fertilization; (8) discuss the clinical implications of the induced acrosome reaction; (9) discuss the relevance of sperm function assays in general; and lastly, (10) discuss future application of acrosome reaction assessment for the clinical diagnosis of male infertility.

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.

Prognostic value of evaluation of total number of morphological anomalies in 100 sperm in semen of infertile men

In this study, the evaluation of the total number of morphological anomalies per 100 sperm was more reliable, as far as potential fertility is concerned than the concentration of sperm per milliliter, the percentage of motile sperm, and the percentage of sperm with normal or abnormal morphology. This parameter allows for discrimination between subfertile and fertile semen and therefore can help in the selection of men who require assisted reproduction techniques.

The postwash total progressively motile sperm cell count is a reliable predictor of total fertilization failure during in vitro fertilization treatment

OBJECTIVE

To predict the chance of total fertilization failure (TFF) before the day of ovum pickup with known semen and female variables.

DESIGN

A statistical model was constructed to predict TFF by retrospective analysis (2,366 couples) and subsequently tested on a new IVF population (917 couples).

SETTING

Academic tertiary referral center.

PATIENT(S)

Three thousand three hundred eighty-three couples who underwent an IVF-ET treatment.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

The ability to predict the probability of TFF in IVF.

RESULT(S)

Two variables-postwash total progressively motile sperm cell count (postwash TPMC) and number of follicles-were found to be significant. Taking a probability of 25% as an acceptable risk of TFF, we calculated that a postwash TPMC of <1.1 x 10(6) cells results in a risk of TFF of >25%. Low responders (<4 follicles) needed a postwash TPMC of >2.2 x 10(6) cells to reduce the risk of TFF to <25%. High responders (>15 follicles) needed only 0.35 x 10(6) postwash progressively motile spermatozoa.

CONCLUSION(S)

When postwash TPMC and number of follicles are known and an unacceptable TFF outcome is expected, one can propose an ICSI procedure a few days before the day of ovum pickup.

The acrosome index, radical buffer capacity and number of isolated progressively motile spermatozoa predict IVF results

BACKGROUND

The accuracy by which a number of newly described semen variables can predict either total fertilization failure (TFF) or pregnancy outcome in IVF, has not previously been investigated. The study aim was, therefore, to determine prospectively the predictive value of these variables.

METHODS

The semen variables investigated were the post-wash total progressively motile sperm cell count (TPMC(post-wash)), the acrosome index (AI), 'cytoplasmic residues' and normal sperm morphology, evaluated according to the strict criteria ('strict criteria'), as well as the fast and slow total radical trapping antioxidant potential ('fast TRAP' and 'slow TRAP' respectively).

RESULTS

The study group (n = 87) showed a mean (+/- SD) number of 10.2 +/- SD retrieved oocytes, 12.6% TFF, a mean fertilization rate of 59.7% and a pregnancy rate of 19.5% (17/87). TFF was significantly predicted by TPMC(post-wash), 'strict criteria', AI and 'cytoplasmic residues' (all P < 0.05). The outcome after embryo transfer was significantly predicted by AI and 'fast TRAP'. Semen samples with an AI <5% and a 'fast TRAP' <1.14 mmol/l in particular did not result in any pregnancies after IVF-embryo transfer.

CONCLUSIONS

Of all the measured and calculated semen variables, TPMC(post-wash) was the best predictor of TFF, whilst AI and 'fast TRAP' were the best predictors of pregnancy after IVF.

Hepatocyte growth factor in human semen and its association with semen parameters

Hepatocyte growth factor (HGF) is a structurally unique growth factor with potent motogenic (motility inducing) effects. Studies in the murine male genital tract have suggested important associations between HGF and the acquisition of sperm motility during epididymal maturation. The aim of this study was, therefore, to determine the concentration of HGF in human semen and assess its correlation, if any, with sperm motility and other semen parameters. Semen samples were collected by masturbation and analysed using standard procedures. HGF concentrations were measured in duplicate using an enzyme-linked immunoassay technique. Total protein estimations were also made in a subset of samples. The 95 subjects were divided into three groups for analysis: normozoospermic, subnormal semen and azoospermic. HGF was detected in all samples (median 0.456, 25th centile 0.388, 75th centile 0.556 ng/ml). No significant correlations were found between semen HGF concentrations and sperm concentration, motility, total sperm count or total motile count. There were no significant differences in mean HGF concentrations between the three subgroups. In conclusion HGF is present in human semen in significant quantities. The data do not suggest HGF concentrations are correlated with parameters of sperm motility.

Prognostic value of male diagnostic profiles in intracytoplasmic sperm injection (ICSI)

Possible correlations between male hormone and semen parameters with pregnancy and oocyte fertilization rates following intracytoplasmic sperm injection (ICSI) were investigated. The study is based on 290 couples who underwent ICSI therapy for the first time. The parameters evaluated were male age, serum levels of follicle stimulating hormone (FSH) and testosterone, sperm concentration, sperm motility, normal sperm morphology, index of teratozoospermia (TZI) and sperm vitality. A marginal, barely significant association was found between the fertilization rate and serum FSH levels in the male partner (p = 0.046). There was no relevant association between male parameters and pregnancy rates. The study confirms that male hormonal and semen parameters are of low prognostic value for the outcome of ICSI.

The influence of psychological factors on the outcome of the fertilization step of in vitro fertilization

Our objective was to determine whether psychological factors have an influence on the outcome of the fertilization step of in vitro fertilization (IVF) trials. The design was a prospective cohort study. We studied 48 women and 32 of their spouses. Each subject was assessed psychologically on the day before oocyte retrieval (OR) with the Child Project Questionnaire (CPQ) and the Ways of Coping Checklist. In addition, the State-Trait Anxiety Inventory was filled in by subjects 2 days before OR, and the State form was completed again for 6 additional days. The outcome measure was the success of the fertilization step. Logistic regression analysis was used to test the influence of psychological factors while taking into account the effect of medical and sociodemographic variables. The following variables were found to be statistically significant predictors of fertilization: normal sperm; tubal lesions or occlusion; women's factor II of the CPQ, i.e. Perception of Marital Harmony in the Project to Conceive a Child. We conclude that, even when the influence of biomedical variables is taken into account, the women's Perception of Marital Harmony in the Project to Conceive a Child, is a statistically significant predictor of the success of the fertilization step of IVF.

Sperm count in ejaculates and after sperm selection with discontinuous percoll gradient centrifugation technique, as a prognostic index of IVF outcome

Success of IVF with low sperm count will depend on the retrieval of the maximum number of normal motile sperms, and this makes the selection of an appropriate technique critical. Various in vitro methods have been developed for selecting human sperm cells. Sperm selection using percoll gradient has been reported to yield upto 60% motile and morphologically normal spermatozoa from a normal semen sample. In this study, we have attempted to determine a possible relationship between sperm count in ejaculates before and after selection with percoll gradient centrifugation on one hand, and fertilization, cleavage and pregnancy rates in an IVF program on the other. With increased sperm count at the time of IVF treatment using selected sperm, we observed higher fertilization, cleavage and gestational rates. In conclusion, sperm concentration before and after selection with percoll may be considered a prognostic parameter for the determination of fertilization potential and pregnancy rates in an IVF program.

The sperm deformity index: a reliable predictor of the outcome of oocyte fertilization in vitro

OBJECTIVE

To evaluate a novel expression of sperm morphological parameters, the sperm deformity index, as a predictor of fertilization in vitro.

DESIGN

Prospective blind clinical trial.

SETTING

Academic tertiary referral center.

INTERVENTION(S)

Detailed sperm morphological assessment applying strict morphological criteria and a multiple entry technique for an unselected male population undergoing IVF. The sperm deformity index, defined as the average number of deformities per sperm assessed, was calculated.

PATIENT(S)

One hundred fifty-eight patients undergoing IVF treatment. Females with conditions negatively influencing fertilization were excluded.

MAIN OUTCOME MEASURE(S)

Fertilization rates and pregnancy.

RESULT(S)

Seventy-three percent of patients achieved fertilization. Patients achieving fertilization had a significantly higher median proportion of normal forms and a significantly lower median sperm deformity index than the nonfertilizers. The receiver operator characteristic (ROC) curves identified cutoff points that maximized the sum of sensitivity and specificity at sperm deformity index 1.6 and normal forms 4%. The sperm deformity index had a greater sensitivity (96%), specificity (72%), positive predictive value (90%), and negative predictive value (86%) than the proportion of normal sperm morphology (87%, 69%, 89%, 66%, respectively) at the optimal cutoff points. The area under the ROC curve was greater for the sperm deformity index (0.875) than for the proportion of normal sperm morphology (0.622). Achieving pregnancy did not correlated with sperm morphology.

CONCLUSION(S)

The sperm deformity index is a more reliable predictor of the outcome of fertilization in vitro than the proportion of normal sperm morphology and can assist to identify patients who require techniques such as intracytoplasmic sperm injection.

Combination of direct swim-up technique and discontinuous Percoll gradient centrifugation for sperm preparation of oligoasthenozoospermic samples

Sperm recovery for assisted reproduction in oligoasthenozoospermic patients is not satisfying either by the swim-up technique or by Percoll gradient centrifugation, and no single technique is constantly preferred. The design of this study was to evaluate the effects of combining the two methods on improving the efficacy of sperm preparation in these poor samples. For each semen sample, 1 mL was treated with a combination method, which used direct swim-up technique to recover motile sperm swimming to the supernatant, and then the residual semen was subjected to two-layer discontinuous Percoll gradient procedure for further recovery of motile sperm. Another 1 mL was prepared with two-layer discontinuous Percoll gradient centrifugation alone for comparison. Parameters measured included sperm concentration, number of progressively motile sperm, percentage of progressive motility, percentage of motile sperm recovery, amount of debris, percentage of normal forms according to Kruger's strict criteria, and motion characteristics of sperm using computer-aided motility analysis. The results of 30 oligoasthenozoospermic samples demonstrated that the combination method achieved a significantly greater recovery of motile sperm than the two-layer discontinuous Percoll gradient centrifugation did (43.2 +/- 19.7% vs. 32.2 +/- 14.3%, p < .05). The percentage of progressive motility was higher in the samples of the combination method than in those of Percoll gradient centrifugation alone, but the difference was not significant (63.7 +/- 21.8% vs. 58.7 +/- 20.1%). The debris of semen was removed equally well by both methods. The percentage of normal forms as well as motion characteristics, including curvilinear velocity, straight-line velocity, mean amplitude of lateral head displacement, and linearity, were similar in the samples treated by these two procedures. The combination of the direct swim-up technique and discontinuous Percoll gradient centrifugation combines the advantages of each procedure and results in greater recovery of motile sperm in oligoasthenozoospermic samples.

Intracytoplasmic sperm injection: a treatment for extreme oligospermia

PURPOSE

We evaluated the efficacy of intracytoplasmic sperm injection in patients with extreme oligospermia.

MATERIALS AND METHODS

A total of 67 intracytoplasmic sperm injection cycles was attempted in 58 infertile couples in which the husbands had extreme oligospermia (less than 100,000 spermatozoa per ml. ejaculate).

RESULTS

Fertilization was achieved in 65 of 67 cycles. Mean fertilization rate per cycle was 66.4%. A total of 18 clinical pregnancies was obtained, for a pregnancy rate of 26.8% per started cycle. There were 4 miscarriages and 8 live births from 5 deliveries. Nine pregnancies are ongoing.

CONCLUSIONS

Intracytoplasmic sperm injection in patients with extreme oligospermia is associated with high fertilization rates and offers the chance of pregnancy to these otherwise intractably infertile couples.

The influence of sperm morphology and the number of motile sperm inseminated on the outcome of intrauterine insemination combined with mild ovarian stimulation

OBJECTIVE

To determine the influence of sperm morphology and the number of motile sperm inseminated on the outcome of IUI in hMG-stimulated cycles and to establish lower limits for these variables below which the expectation of pregnancy is limited.

DESIGN

Retrospective study of data from 1990 to 1992.

SETTING

Tertiary referral Reproductive Medicine Unit.

PATIENTS

Couples with bilaterally patent fallopian tubes, and > or = 200,000 motile sperm recovered in a trial preparation before treatment. No other semen criteria were used to exclude couples. Women were stimulated with hMG irrespective of whether they were ovulatory or anovulatory. The study comprised 163 couples who underwent 330 cycles.

MAIN OUTCOME MEASURES

Pregnancy rate (PR) per cycle was related to the percentage normal sperm morphology in the fresh semen sample and the number of motile sperm inseminated after sperm preparation by swim-up or Percoll gradients.

RESULTS

The overall PR was 16.1% per cycle. The PR was highest in the first cycle of treatment (21.4%) and declined in the second and third cycles. The miscarriage rate was 10.4% and the incidence of multiple pregnancies was 13.9%. Two groups of patients were defined on the basis of sperm morphology: a "poor outcome" group ( < or = 10% normal) and a "good outcome" group ( > 10% normal). The PRs in these two groups were 4.3% and 18.2%, respectively, and the cumulative PRs after three cycles were 8.3% and 40.1%, respectively. The number of motile sperm inseminated did not significantly affect the PR.

CONCLUSIONS

The degree of teratozoospermia affected the PR in hMG-stimulated IUI cycles and a normal morphology value of 10% in the fresh semen distinguished couples with good and poor outcomes. In contrast, the number of motile sperm inseminated did not significantly influence IUI outcome.

In vitro fertilization outcome in the presence of severe male factor infertility

OBJECTIVE

To assess the outcome of standard IVF treatment (nonmicromanipulated) with respect to total motile sperm number recovered by swim-up, particularly for couples with severe male factor infertility defined as total motile sperm number < 0.5 x 10(6).

DESIGN

Retrospective study of patients who underwent successful oocyte retrieval in an IVF program from August 10, 1992 to December 31, 1993.

SETTING

A university-based tertiary referral center (The Toronto Hospital).

PATIENTS

All cycles (n = 672) were divided into four groups according to total motile sperm number recovered using standard swim-up: group 1, total motile sperm number < or = 0.50 x 10(6); group 2, total motile sperm number between 0.51 and 1.00 x 10(6); group 3, total motile sperm number between 1.01 and 1.50 x 10(6); and group 4, total motile sperm number > or = 1.51 x 10(6). All patients received the same controlled ovarian hyperstimulation protocol, which consisted of a GnRH analog flare-up followed by parenteral menotropins. Clinical and cycle characteristics in the four groups were analyzed and outcome was evaluated.

RESULTS

There was no significant difference in clinical and cycle characteristics between the groups. The uniformity of the groups justified analysis of their outcome. A fertilization rate of 21.5% was achieved in couples with severe male factor (group 1). Fertilization rate and number of embryos transferred increased directly with the total motile sperm number. There was no significant difference in implantation rate per embryo between the groups.

CONCLUSIONS

The results in couples with severe male factor infertility compare favorably with monospermic fertilization rates reported in the literature using partial zona dissection and subzonal insertion but is lower than with intracytoplasmic sperm injection. Therefore, we believe that couples with severe male factor infertility should be considered for standard IVF, as long as adequate total motile sperm can be recovered (100 x 10(3) per dish). If intracytoplasmic sperm injection is available, it should be offered to these couples.

Correlation between sperm morphology using strict criteria in original semen and swim-up inseminate and human in vitro fertilization

To study the value of sperm morphology using strict criteria in raw semen and in swim-up inseminate of human in vitro fertilization (IVF), 135 cycles of IVF with normal sperm concentration and motility were recruited. At least two mature oocytes were recovered in each cycle. The correlation between the percentages of normal forms and fertilization rates of mature oocytes was analyzed. The results demonstrate that the percentage of normal forms in both the raw semen and swim-up sample of patients with poor fertilization was significantly lower than in those with acceptable fertilization. The percentages of normal forms both in raw semen and in swim-up sample were significantly correlated with fertilization rates in vitro, however, the former seemed to have a better correlation (r = .51 and .19, respectively). Regarding the percentages of normal forms in raw semen, the fertilization rate in patients with normal forms < 4% was 6 +/- 11%, for 4-14% it was 58 +/- 36%, and for > 14% it was 88 +/- 20%. The fertilization rates were significantly different among these three groups of patients. The evaluation of sperm morphology using strict criteria in raw semen before IVF is predictive of fertilization outcome and may also help doctors to choose an optimal method of treatment for patients.

Association of elevated estradiol with remote testicular trauma in young infertile men

OBJECTIVE

To determine the incidence of remote testicular trauma and of possible related permanent hormonal and seminal changes in infertile men.

DESIGN

Retrospective clinical study of hormonal and seminal parameters in a subpopulation of infertile men.

SETTING

Andrology Clinic in an academic research environment.

PARTICIPANTS

Infertile men, with and without history of remote testicular trauma, and fertile volunteers.

MAIN OUTCOME MEASURES

Percentage of infertile men with history of blunt testicular trauma, concentrations of reproductive hormones, and semen parameters.

RESULTS

Significant remote blunt testicular trauma was reported by 16.8% of infertile men. This had occurred 2 to 17 years (mean, 16.4 years) before evaluation, mostly with contact sports at adolescent age. Estradiol concentrations after testicular trauma were 19% and 25% higher than in infertile men without history of testicular injury and in fertile controls. Elevated E2 levels did not correlate with T. Infertile men with and without history of testicular trauma showed changes in seminal parameters.

CONCLUSION

The incidence of remote blunt testicular trauma in infertile men is unexpectedly high. After injury, FSH-stimulated aromatization of T may increase testicular E2 production, interfere with spermatogenesis, and cause infertility. Consistent use of protective devices in contact sports is recommended.

Microassisted fertilization in assisted conception: indications and patient impact

Microassisted fertilization is fast becoming established as a routine clinical technique offering the chance of pregnancy to couples where none existed previously. The exceptional results of SUZI and, more particularly, ICSI now raise the prospect of pregnancy with any sperm in the ejaculate and are bringing to treatment focus some azoospermic men and men without an antegrade ejaculate. The advance in clinical results from SUZI and ICSI over earlier zona drilling and zona breaching techniques appear to be importantly related to the better implantation potential of the embryos. The implications for the way conventional IVF is performed still need to be digested but may be very important and may change our attitude to ovarian stimulation and insemination regimens.