Predictive value of morphologically normal sperm concentration in the medium for in-vitro fertilization

Eliminating the effect of pathomorphologically formed sperm on resulting gravidity using the intracytoplasmic sperm injection method

The aim of the present study was to test whether it is possible to eliminate a high percentage of morphologically abnormal sperm in male ejaculate by assisted reproduction using the intracytoplasmic sperm injection (ICSI) method. Treatment success was evaluated by comparing fertilization, clinical pregnancy and reproduction rates between males with heavy teratospermia (≤1% morphologically normal spermatozoa) and males with a higher percentage (>1%) of normal sperm. In total, 174 patients who had previously undergone 174 ICSI cycles (1 per each pair) were evaluated retrospectively. In the group of patients with heavily impaired sperm morphology (n=37), the percentage of normal spermatozoa was ≤1%. In the second group, males with >1% normal spermatozoa (n=137) were considered as patients with mildly impaired sperm morphology. The results of partner fertilization in these two groups were compared and a lower number of fertilized oocytes was identified in the patients with heavily impaired sperm morphology (P=0.038). However, neither the gravidity nor the take-home baby rates of the partners differed between the patients with mildly and heavily impaired sperm morphology. Trends opposite to that for fertilization were observed for gravidity and delivery [odds ratio (OR), 0.62; 95% confidence interval (CI), 0.29–1.30; OR, 0.55; 95% CI, 0.26–1.24, respectively]. This indicates that the lower number of fertilized oocytes was not associated with the overall outcome of fertilization and that patients with heavily impaired sperm morphology experience the same benefit from ICSI as patients with mildly impaired sperm morphology.

Laboratory standards in routine clinical andrology

It is a fundamental principle of laboratory tests that they are never entirely free from error. However, understanding the source and extent of such errors is a prerequisite for correct appreciation and interpretation of test results in the diagnostic process. In order to evaluate these errors, quality control (QC) has been introduced into clinical laboratory tests and has become routine practice.

Increase in the concentration of cytosolic-free calcium induced by human follicular fluid was decreased in single human spermatozoon with abnormal morphology

Aim:  The increase in the concentration of cytosolic-free calcium ([Ca²⁺]i) induced by follicular fluid or progesterone has been reported to promote an acrosome reaction and alternation in several motion parameters in human sperm (hyperactivation). We previously reported that populations of sperm in cell suspension obtained from infertile men with abnormal morphology exhibited lower mean peak progesterone-evoked [Ca²⁺]i compared with morphologically normal sperm using cell-suspension methods. In the present study, the change in [Ca²⁺]i in individual normally and abnormally shaped spermatozoa was compared. Methods:  The change in [Ca²⁺]i induced by human follicular fluid in individual spermatozoa with normal and abnormal morphology was compared using the fluorescent calcium-sensitive dye fluo-3/AM. The spatial distribution of the increase in [Ca²⁺]i in single sperm was also investigated. Results:  The [Ca²⁺]i of normally shaped spermatozoa increased rapidly after the administration of human follicular fluid. The response reached a peak within 2-3 s and then slowly declined to a plateau phase. The baseline and peak fluorescence in spermatozoa with abnormal morphology was lower when compared with normal spermatozoa. The follicular-fluid-induced increase in [Ca²⁺]i (expressed as a percentage increase in [Ca²⁺]i over basal) in morphologically abnormal sperm was 39.2 ± 5.3% (n = 107, mean ± standard error), which was smaller than that of morphologically normal sperm (61.6 ± 5.7%, n = 100, P < 0.005) from seven healthy donors. The follicular-fluid-induced [Ca²⁺]i increases observed in sperm with morphologically abnormal mid-pieces (20.9 ± 4.3%, n = 12, P < 0.05) or tails (40.7 ± 6.0%, n = 92, P < 0.05) were lower than those of morphologically normal spermatozoa (61.6 ± 5.3%, n = 101). The follicular-fluid-induced [Ca²⁺]i increase of morphologically normal spermatozoa from infertile couples (35.1 ± 6.3%, n = 25, P < 0.05) was also found to be lower than that of morphologically normal spermatozoa from healthy donors. Conclusion:  The present study shows that spermatozoa with abnormal morphology in healthy donors have disorders of signal transduction, as do normally shaped sperm in men from infertile couples. (Reprod Med Biol 2008; 7: 143-149).

Is abnormal sperm function an indicator among couples with recurrent pregnancy loss?

OBJECTIVE

To determine whether or not sperm function parameters are altered in male partners of couples with a history of idiopathic recurrent pregnancy loss (RPL).

DESIGN

In comparison with proven fertile volunteers, sperm function parameters like hypo-osmotic swelling (HOS), acrosomal status (AS), and nuclear chromatin decondensation (NCD) were assessed in vitro from male partners of couples with a history of idiopathic RPL.

SETTING

Infertility clinic and andrology laboratory at National Institute of Health and Family Welfare.

PATIENT(S)

Male partners of couples with a history of idiopathic RPL and proven fertile male volunteers (control).

INTERVENTION(S)

Standard semen analysis, assessment of sperm morphology, and sperm function with tests such as HOS, AS, and NCD.

MAIN OUTCOME MEASURE(S)

Sperm paameters, such as HOS, AS, and NCD, were assessed in semen samples from RPL in comparison with the proven fertile control group.

RESULT(S)

Semen samples from the idiopathic RPL group showed below normal test scores in 57.1% of the cases for all three sperm parameters. The highest aberration (83% of cases) in sperm attributes was observed in NCD, followed by AS (45.7%) and HOS (42.9%). In contrast, abnormality in sperm morphology was limited to 5.7% of the cases. Subnormal sperm function is directly proportional with subnormal sperm motility (<50%) in 23% of the cases. Even in semen samples with normal sperm motility, sperm function scores were below normal in 31.4% of the RPL group.

CONCLUSION(S)

Reduction in test scores of sperm function, like HOS, AS, and NCD, in male partners of couples with idiopathic RPL suggests that sperms with altered or lowered functional competencies, if they fertilize the oocytes, may lead to the development of an unsustainable embryo resulting in early pregnancy loss. Normal sperm motility does not always ensure normal sperm function scores.

The establishment of sperm morphology satellite training laboratories in Africa

Summary Discrepancies in the results of semen analysis can be caused by a variety of factors, for example, a microscope for semen analysis can be situated in the practice of an urologist, cytologist or microbiologist, or even in a health care office in the countryside in a developing country. The study aimed to evaluate the (i) sperm morphology assessment skills of the participants who attended WHO seminology workshops and (ii) to appraise the possibility of using trained technologists to set up satellite training facilities in their own area. The Centre for Research in Reproductive Health, Ogun State University Teaching Hospital (Nigeria) initiated training sessions in their area. Subsequently, 16 technologists were trained in three sessions. Papanicolaou-stained slides, supplied by Tygerberg were used as test material. Pre- and post-training results were used to calculate the mean percentage of normal cells as well as the percentage deviation from the reference laboratory. The mean percentage normal spermatozoa recorded by the Nigerian trainees during pre-training evaluations differed by 38% from the reference value, compared with a post-training difference of 16% (P < 0.001). Tertiary academic hospitals can play an important educational role in the region. The present results underline the power of long distance educational programmes. Similar laboratories are currently being set up in Kenya and Zambia.

Accuracy of the normal sperm morphology value by Sperm Quality Analyzer IIC: comparison with the strict criteria

The aim of the present study is to investigate the accuracy of the normal sperm morphology value by Sperm Quality Analyzer IIC (SQA IIC), which was developed to provide a rapid and low-cost quantitative evaluation of semen quality. Normal sperm morphology was assessed using SQA IIC in comparison with that by the strict criteria in 62 semen samples. Normal sperm morphology value by SQA IIC was based on the studies of three traditional sperm parameters from over 4000 fresh, untreated semen samples, while the strict criteria was based on the method by Kruger et al. The mean +/- SD of percent normal morphology by SQA IIC and the strict criteria were 37.6 +/- 10.9% (range 15-52) and 19.9 +/- 8.2 (range 1-34), respectively. There was a significant correlation of the sperm morphology assessment between the two methods (r=0.454, p < 0.001). Using the cut-off value of >30% normal morphology by SQA IIC, the positive predictive value and the negative predictive value of the 'normal' strict criteria were 79.6% (39/49) and 46.2% (6/13), respectively. These results indicate that SQA IIC might be used as an initial screening test for the evaluation of sperm morphology. However, sperm morphological assessment by the strict criteria should be performed in order to make decisions in planning strategies for the treatment of infertile couples.

Comparison of sperm preparation methods: effect on chromatin and morphology recovery rates and their consequences on the clinical outcome after in vitro fertilization embryo transfer

The aim of this study was to evaluate the efficacy of swim-up, PureSperm gradient centrifugation and glass-wool filtration methods for semen preparation and to assess the possible enhancement of the quality of the subpopulation of spermatozoa in terms of sperm concentration, morphology and chromatin condensation. Moreover, to determine the effect of this semen processing technique on the clinical outcome after in vitro fertilization embryo transfer (IVF-ET). A total of 180 semen samples of patients' husbands who were undergoing IVF therapy were prepared by swim-up (G1, n = 60), PureSperm gradient centrifugation (G2, n=60) or glass-wool (G3, n=60) methods. Chromatin condensation was assessed by Chromomycin (CMA3), whereas sperm morphology was evaluated according to strict criteria. In all three semen processing methods, the percentage of chromatin condensed and morphologically normal spermatozoa was higher after semen processing in comparison with native semen samples. The proportion of normal chromatin condensed spermatozoa prepared in glass-wool filtration was significantly higher than that in swim-up (G.I, p=0.02) or PureSperm (G.II, p=0.001). In addition semen processing with PureSperm yields significantly a higher percentage of morphologically normal spermatozoa than swim-up (p < 0.001) or glass-wool method (p < 0.002). However, the fertilization, implantation and pregnancy rates, in turn were similar in all semen preparation methods. In conclusion, PureSperm gradient centrifugation yields a higher percentage of morphologically normal spermatozoa than shown in traditional swim-up or glass-wool filtration. However, the percentage of chromatin condensed spermatozoa was significantly higher after semen processing via glass-wool in comparison with the other two methods. Nevertheless, there were no significant difference in the fertilization, implantation and pregnancy rates of sperm prepared by means of swim-up, PureSperm or glass-wool filtration. Therefore, glass-wool filtration should be recommended as the first choice for semen preparation for Intracytoplasmic sperm injection (ICSI) technique as the natural selection is bypassed. Whereas, swim-up and PureSperm should be used for semen processing in IVF programme.

Prediction of unexpectedly poor fertilization and pregnancy outcome using the strict criteria for sperm morphology before and after sperm separation in IVF-ET

This study was performed to investigate if unexpectedly poor fertilization and in-vitro fertilization (IVF) outcome could be predicted using sperm morphology as diagnosed by the strict criteria. Sperm morphology was assessed in 137 IVF-ET cycles with at least three oocytes collected. The lowest amount of normal forms was 5% in 137 samples, indicating there were no patients belonging to 'poor prognosis' (<5% normal forms). Treatment using intracytoplasmic sperm injection (ICSI) was also excluded. Before sperm separation by the swim-up method, sperm morphology demonstrated a significant correlation with the fertilization rate (p < 0.0001). The fertilization rate (80.5%) in 110 'normal' samples (>14% normal forms) was significantly higher (p < 0.01) than that (55.4%) in 27 samples with 'good prognosis' (those with 5--14% normal forms). No embryo was available for transfer (ET) in 4 (3.6%) of 110 'normal' cycles and in 3 (11.1%) of 27 'good prognosis' cycles (not significant). Fresh ET was intentionally cancelled to avoid severe ovarian hyperstimulation syndrome (OHSS) in six of 110 'normal' cycles as well as in one of 27 'good prognosis' cycles. The pregnancy rate per ET was 31.0% (31/100) in the former group, while it was 26.1% (6/23) in the latter group. There was no difference between the two groups. In the post swim-up evaluation of sperm characteristics, morphology was significantly correlated with the fertilization rate in IVF-ET (p < 0.05) while other sperm parameters were not. When the cut off level for the post swim-up sperm morphology was set at 25%, there was a significant difference in the fertilization rates between patients (78.6%) with post-swim-up >25% and those (55.0%) with post-swim-up < or =25% (p < 0.01). Taken together, a relative indication for ICSI using sperm morphology before and after swim-up was established. Category A includes < or =14% normal forms in the ejaculate and post-swim-up < or =25%, while Category B includes < or =14% in the ejaculate and post-swim-up >25%. There was a significant difference in the fertilization rates between patients (47.2%) in Category A and those (60.2%) in Category B (p < 0.05). The clinical pregnancy rate was 11.1% for patients in Category A compared with 35.7% for patients in Category B. However, there was no significant difference between the two categories. These results indicate that the strict criteria provide a reliable estimation of the fertilizing ability of human spermatozoa. ICSI might be considered in Category A patients to avoid poor fertilization and pregnancy outcome.

Preparation by differential gradient centrifugation is better than swim-up in selecting sperm with normal morphology (strict criteria)

OBJECTIVE

To evaluate two commonly used methods of sperm preparation with respect to their effects on sperm morphology (strict criteria).

DESIGN

Auto-controlled, split sample study performed on the semen of 74 male partners of couples enrolled for IVF.

SETTING

In vitro fertilization and andrology laboratories at a tertiary care, major teaching hospital.

PATIENT(S)

Seventy-four male partners of couples who were scheduled to undergo IVF.

INTERVENTION(S)

Equal halves of the same semen sample were evaluated for strict criteria sperm morphology before and after preparation by differential gradient centrifugation using Percoll (Pacific Andrology, Montrose, CA) and by the standard swim-up method.

MAIN OUTCOME MEASURE(S)

The percentage of morphologically normal sperm was assessed using strict criteria before and after the two methods of sperm preparation. Specific parameters studied were individual abnormalities of the head, midpiece, and tail.

RESULT(S)

Sperm preparation using differential gradient centrifugation with Percoll produced a significantly greater number of specimens with normal sperm morphology and also showed higher absolute quantitative improvement over the swim-up method. The two methods were comparable in regard to their effects on specific sperm abnormalities (i.e., head, midpiece, and tail defects).

CONCLUSION(S)

The differential gradient sperm separation method using Percoll is superior to the swim-up method for selecting sperm with normal morphology as assessed by strict criteria. Because sperm morphology as assessed by strict criteria is a good predictor of oocyte fertilization, this method can be recommended as the method of choice for assisted reproductive technology laboratories. Use of this method may help improve outcome by increasing fertilization rates.

Acrosin activity in pelleted frozen sperm does not correlate with in vitro fertilization of oocytes

Spermatozoa pelleted after swim-up were frozen and then analysed in batches for acrosin activity, using a spectrophotometric method, and expressed as microIU micrograms DNA-1. A total of 259 sperm samples were analysed and the acrosin activity compared with fertilization in vitro. Of these, 224 samples fertilized at least one oocyte and 35 samples failed to fertilize any oocyte. Analysis by Student's t-test indicated that there was a statistically significant difference (P = 0.02) in acrosin activity between the two groups. However, when samples that failed to fertilize were matched for concentration, motility and normal morphology with samples that fertilized, this significance was lost (P = 0.77). It is concluded that total acrosin in pelleted sperm frozen after regular swim-up, does not correlate with fertilizing ability of spermatozoa used for insemination.

Slide preparation and staining procedures for reliable results using computerized morphology

The purpose of this study was to standardize slide preparation and staining procedures to improve the efficiency and effectivity of the IVOS system on normal sperm morphology readings with regard to the strict criteria. Semen samples from patients attending the Reproductive Biology Unit, Tygerberg Hospital, were used. In experiment 1, five different Diff-Quik staining procedures, including the standard procedure, were evaluated on each of 22 patients and the effect of slide preparation within 1 h or more than 5 h after collection and the effect of immediate fixation versus fixation after 24 h were observed. In experiment 2, the manual evaluation time per slide (n = 20) by two technicians was compared with the time taken by computer. In experiment 1 the median % normal for the 5 different staining procedures was 6, 6.5, 9.5, 8.5, and 5.5%. No significant difference was found between the different staining procedures (p = .60, nonparametric Friedman test). In experiment 2 the mean time for manual assessment by two technicians was 3 min:6 s and 3 min:53 s per slide as compared to 4 min:39 s by computer. For experiment 1, slides can be prepared immediately or after 5 h. Fixation time also does not interfere with the computer's ability to identify normal forms. For experiment 2, the IVOS system is competitive regarding assessment time. Standardization of optimum staining procedures is important to ensure repeatability and comparability. Therefore, slides should be prepared immediately after liquefaction and fixed immediately after air drying.

Sperm morphology: assessing the agreement between the manual method (strict criteria) and the sperm morphology analyzer IVOS

OBJECTIVES

To correlate the percentage normal morphology reported by different observers and a computerized method (IVOS; Hamilton-Thorne Research, Beverly, MA) on a slide-by-slide basis using strict criteria: [1] Experienced observer (T.F.K.) versus experienced observer (R.M.), [2] experienced observer (T.F.K.) versus sperm morphology analyzer (IVOS), and [3] repeatability of normal and abnormal cells (IVOS). DESIGN SETTING, PATIENTS: Slides from 30 different patients from the Tygerberg IVF program were selected randomly. Microscopic fields and sperm cells were chosen randomly and percent normal morphology was recorded (objectives 1 and 2). The same slides were used and a cell-by-cell repeatability was done as outlined (objective 3).

RESULTS

Experiment 1 (objective 1): there was no significant bias between T.F.K. and R.M. The limits of agreement were 8.6% and -7.3%. The SDs were not significantly different (P = 0.1283). The Spearman correlation coefficient between readers was 0.83. Experiment 2 (objective 2): the same findings were reported but the limits of agreement were 12.1% and -15.5%. The Spearman correlation coefficient was 0.85. The limits of agreement was tighter below 20% normal forms (+8.4 and -6.6). Experiment 3 (objective 3) (repeatability): 255 cells were analyzed three times in succession. Estimating pairwise agreement, the kappa statistic for the pairs are 0.85, 0.80, and 0.85, respectively, which compares favorably with the second canonical moment of 0.8329 (kappa = 0.83).

DISCUSSION

The computer's ability to classify normal morphology per slide is promising. Below 20% normal forms, the limit of agreement is tight. Because of the 6% higher reading compared with the manual method, different thresholds possibly will be developed to identify subfertile from fertile patients. The computer gives excellent repeatability of normal and abnormal cells. Based on results obtained, this system can be of clinical value both in IVF units and andrology laboratories but more clinical data is required in this field.