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Biomedical subjects

G Verheyen

Publications and source records attributed to G Verheyen.

At least 55 records · Page 3Linked to original sources
PubMed1997

Relationship between serum follicle stimulating hormone in the male and standard sperm parameters, and the results of intracytoplasmic sperm injection.

Serum follicle stimulating hormone (FSH) is routinely measured when evaluating the infertile male for intracytoplasmic sperm injection (ICSI). However, among the sperm parameters, only its relationship with sperm concentration is well documented. Few investigations concern the relationship between FSH and sperm motility and morphology, and the results of ICSI. A retrospective study of 316 couples who underwent ICSI was carried out to determine the relationships between serum FSH concentrations in the male and (i) standard sperm parameters_(concentration, motility and morphology) and (ii) fertilization, cleavage, pregnancy and implantation rates after ICSI. There was an inverse correlation with sperm concentration and total motility but no relationship was found with progressive motility and sperm morphology. Neither was any relationship found between serum FSH and fertilization, cleavage, pregnancy and implantation rates, and the results of ICSI. These findings suggest the need to review the routine measurement of serum FSH in the infertile male when ICSI is the planned treatment procedure.

Female↗
PubMed1997

Are there any predictive factors for successful testicular sperm recovery in azoospermic patients?

Recovery of testicular spermatozoa from azoospermic patients with testicular failure followed by intracytoplasmic sperm injection (ICSI) is a recent advance in the treatment of male infertility. This study aimed at investigating which parameter(s) may predict successful testicular sperm recovery. We reviewed 395 testicular sperm recovery procedures and analysed the most frequently available parameters for clinical decision-making in azoospermic patients: (i) presence of at least one single spermatozoon in at least one preliminary semen analysis; (ii) maximum testicular volume; (iii) serum follicle stimulating hormone (FSH); and (iv) presence of spermatozoa in the histology of a randomly-taken testicular biopsy. Sensitivity, specificity, positive and negative predictive value, positive and negative likelihood ratio and accuracy were calculated for the above index parameters in different clinically relevant subgroups using receiver operating characteristic (ROC) curves whenever possible. Spermatozoa were always successfully recovered in patients with normal testicular histological findings (n = 173) or hypospermatogenesis (n = 16) but not in some patients with tubular sclerosis (seven out of 18), Sertoli cell-only pattern (55 out of 112) or maturation arrest (39 out of 76). Histopathology was the best test for predicting successful sperm recovery in the whole population (sensitivity: 86%, specificity: 93%, accuracy: 0.87). In patients with secretory azoospermia, histopathology was again the most accurate parameter (accuracy: 0.74), especially in patients showing Sertoli cell-only pattern (accuracy: 0.83) but not in patients showing maturation arrest (accuracy: 0.55). In patients with serum FSH concentrations > 12 IU/l and maximum testicular volume < 15 ml, histopathology was not found to be accurate. Semen analysis, maximum testicular volume and serum FSH were not highly predictive in all subgroups studied. Our analysis shows that no strong predictors for successful testicular sperm recovery are available except for testicular histopathology.

Adult↗
PubMed1997

No evidence for a decreased fertilizing potential after in-vitro fertilization using spermatozoa from polyzoospermic men.

Polyzoospermia is generally recognized as a male factor contributing to infertility and/or recurrent abortion. Although a reduced spermatozoal fertilizing capacity is assumed to be involved, so far there is no conclusive explanation for the assumed reduced reproductive performance in these patients, and data on the fertilizing capacity of spermatozoa from polyzoospermic men are lacking. The present study therefore aimed at analysing the outcome after in-vitro fertilization (IVF)-embryo transfer in polyzoospermic patients. Retrospective analysis showed that only 0.5% out of 7863 IVF cycles were performed with spermatozoa from polyzoospermic men. The outcome of these IVF cycles shows neither a reduction in spermatozoal fertilizing capacity nor an increase in pregnancy wastage in cycles in which a pregnancy was obtained. These results may suggest a normal reproductive potential in polyzoospermic patients and therefore the question may be raised whether polyzoospermia represents a real pathological entity leading to infertility.

Embryo Transfer↗
PubMed1997

The use of enzymatic procedures to recover testicular germ cells.

Intracytoplasmic sperm injection (ICSI) with testicular spermatozoa and ejaculated spermatids has been applied successfully to treat infertility because of azoospermia due to obstruction or testicular failure. In most cases, free spermatozoa are recovered from testicular tissue after mechanical mincing of multiple biopsies. Testicular sperm retrieval, however, remains unsuccessful in a high proportion of male patients suffering from testicular failure. In the present study, four media for enzymatic collagen digestion of testicular tissue were compared on 15 testis biopsies obtained from azoospermic patients following an ICSI treatment and on five biopsies from orchiectomy patients. To dissociate the testicular tissue, collagenase type IA, collagenase type IV, collagenase type IA supplemented with elastase and collagenase type IV supplemented with elastase were used. The preparations with only collagenase type IV provided the best dissolution of the cells from their tissue, with a higher yield of free vital testicular spermatozoa and single round germ cells. Enzymatic digestion of testicular tissue has the advantage, especially in cases of testicular failure, that several biopsies can be concentrated into one pellet of single cells. In this way, the sperm retrieval in cases of testicular failure might be optimized to yield the maximal numbers of spermatids and/or spermatozoa.

Adult↗
PubMed1996

The use of testicular sperm for intracytoplasmic sperm injection in patients with necrozoospermia.

OBJECTIVE: To investigate whether intracytoplasmic sperm injection (ICSI) using testicular spermatozoa from necrozoospermic patients results in acceptable fertilization and transfer rates. DESIGN: Retrospective clinical study. SETTING: Tertiary referral center. PATIENTS: Five patients presenting consistently with 100% dead spermatozoa in their ejaculates. INTERVENTIONS: In seven treatment cycles, an open testicular biopsy was performed to increase the chances for retrieving viable spermatozoa which were used for ICSI. MAIN OUTCOME MEASURES: Sperm recovery, fertilization, and transfer rates. RESULTS: Testicular sperm were recovered in all treatment cycles and fertilization occurred in six of seven cycles. Overall normal fertilization and transfer rates were 67% and 71%, respectively. One live birth was obtained after five ETs. CONCLUSION: We recommend testicular sperm recovery for ICSI in patients who invariably or occasionally present with absolute necrozoospermia.

Adult↗
PubMed1996

Cytogenetics of infertile men.

Chromosomally derived sterility has long been recognized. A review of the literature of somatic chromosome investigations in infertile males has shown that 13.7% of azoospermic males and 4.6% of oligozoospermic males have an abnormal karyotype. In the first group, sex chromosome abnormalities predominate (mainly 47,XXY), whereas in the latter, autosome anomalies (i.e. Robertsonian and reciprocal translocations) are the most frequent. A similar review on meiotic studies revealed that meiotic chromosome anomalies can explain male infertility in 4.3-40.4% of patients. Recently, fluorescent in-situ hybridization studies on spermatozoa from infertile men were published; it was suggested that both X-Y pairing and pairing of the autosomes were impaired, resulting in spermatogenic disruption. We investigated cytogenetically 694 infertile men with abnormal sperm parameters. More patients are needed for this research to investigate the relationship, if any, between the type of chromosome abnormality and its influence on the number, morphology and motility of spermatozoa. To be able to provide proper counselling for those couples whose male infertility can now be treated by intracytoplasmic sperm injection, it is suggested that clinical investigations should include mitotic and meiotic studies, an analysis of the chromosome content of individual spermatozoa and a DNA analysis of blood and spermatozoa to detect partially deleted Y chromosome material.

Chromosome Aberrations↗
PubMed1995

Comparison of four mechanical methods to retrieve spermatozoa from testicular tissue.

To maximize the total number of spermatozoa which can be retrieved from a testicular biopsy, four mechanical methods for preparation were compared. In all, 17 biopsies were divided into four equal fractions, which were weighed individually and prepared by rough shredding (control), fine mincing, vortexing and crushing (electrical Potter). After resuspension in an erythrocyte-lysing buffer, removal of the remaining tissue pieces, washing and centrifugation, the following parameters were evaluated: number of spermatozoa per 100 mg tissue, percentage motility, percentage vitality and percentage normal morphology (strict Kruger criteria). After further purification by discontinuous Percoll centrifugation, the same parameters were assessed again. This procedure was efficient in obtaining only spermatozoa in the final fraction. Before Percoll centrifugation, only minor differences between methods were observed. Percoll centrifugation generally resulted in a pronounced loss of sperm cells, partly because of the abnormal dimensions of the eliminated cells. After Percoll centrifugation, treatment of the testicular tissue by fine mincing was the most effective method in terms of the total number of motile spermatozoa and percentage normal morphology.

Adult↗
PubMed1995

Ongoing pregnancies and birth after intracytoplasmic sperm injection with frozen-thawed epididymal spermatozoa.

In seven patients who did not become pregnant following microsurgical epididymal sperm aspiration (MESA) and intracytoplasmic sperm injection (ICSI), a subsequent ICSI was performed using previously cryopreserved super-numerary epididymal spermatozoa without re-operating on the husband. During the original MESA procedure a mean sperm concentration of 12.3 x 10(6)/ml was achieved. The supernumerary spermatozoa were cryopreserved for later use. After thawing frozen epididymal spermatozoa a mean concentration of 1.9 x 10(6) spermatozoa/ml was obtained in straws containing a total volume of sperm suspension of 250 microliters. From 68 intact oocytes injected with frozen-thawed epididymal spermatozoa, a two pronuclear fertilization rate of 45% and a cleavage rate of 82% were obtained. A total of 17 embryos were replaced in the seven patients, resulting in two ongoing singleton pregnancies and one twin delivery. Six embryos were cryopreserved. In conclusion, it would appear mandatory to cryopreserve supernumerary spermatozoa during a MESA in order to avoid subsequent further scrotal surgery.

Adult↗
PubMed1995

The result of intracytoplasmic sperm injection is not related to any of the three basic sperm parameters.

High success rates have been reported for the use of intracytoplasmic sperm injection (ICSI) in alleviating essentially andrological infertility. However, neither the relationship between any of the sperm parameters and the result of ICSI nor the minimal sperm requirements for ICSI have been investigated so far. In this paper, our objective was therefore to study the relationship between three basic sperm parameters (total sperm count, sperm motility and morphology) and the outcome of ICSI by retrospective analyses of fertilization, embryo development and pregnancy rates in 966 micro-injection cycles, performed with ejaculated semen. The results showed that there was no important influence from either the type or the extent of sperm impairment on the outcome of ICSI. Even in the most extreme cases of male-factor infertility, where cryptozoospermia or total astheno- or total teratozoospermia was diagnosed in the initial semen sample, high fertilization and pregnancy rates were obtained by ICSI. Only one condition had a strongly negative influence on the result of ICSI: where an immotile (presumably dead) spermatozoon was injected into the oocyte. Thus the only ultimate criterion for successful ICSI is the presence of at least one living spermatozoon per oocyte in the pellet of the treated semen sample used for micro-injection.

Cytoplasm↗
PubMed1995

Results of 55 intracytoplasmic sperm injection cycles in the treatment of male-immunological infertility.

Antisperm antibodies present in the semen can be a primary cause of infertility. If the proportion of spermatozoa carrying antisperm antibodies is very high, then usually a poor result ensues in standard in-vitro fertilization. We therefore employed intracytoplasmic sperm injection (ICSI) in 55 cycles (37 patients) where the proportion of antisperm antibody-bound spermatozoa was 80% or higher, as determined by the mixed antiglobulin reaction (MAR) test. The type and location of antisperm antibodies were determined by the immunobead test in 30 of the 37 patients. The mean normal fertilization rate was 75.7% in these 55 cycles, which was significantly higher than the fertilization rate in another 1767 ICSI cycles (69.2%) performed over the same period and where MAR-negative semen (the level of antisperm antibodies was < 80%) was used for microinjection. Embryonic development was comparable, but a higher proportion of poor-quality embryos was obtained with MAR-positive than with MAR-negative semen samples. Out of the 55 patients, 53 had embryos replaced (96.4%) and a fetal sac was detected by ultrasonography in 14 patients (26.4%). The data indicate that fertilization, embryo development and pregnancy rates after ICSI are not influenced significantly by the proportion of antisperm antibody-bound spermatozoa, nor by the dominant type of antibodies present, nor by the location of the antisperm antibody on the spermatozoa. The conclusion of this study is that ICSI should be the primary choice for patients who have high numbers of antisperm antibodies present in their semen.

Adult↗
PubMed1994

The effect of pentoxifylline on in-vitro fertilization in the presence of anti-sperm antibodies.

In cases of severe immunological male-factor infertility, impairment of spermatozoal motility and of acrosome reaction resulting in reduced fertilization capacity have been described by several authors. The present study investigated the use of pentoxifylline in enhancing in-vitro fertilization (IVF) in the presence of anti-sperm antibodies. Thirty-seven IVF cycles were conducted in 28 different couples suffering from immunological male-factor infertility with at least 50% antibody-coated spermatozoa. Sibling oocytes were inseminated at random with spermatozoa incubated with or without 3.6 mM pentoxifylline after selection by a Percoll gradient. No difference in motility of the final sperm preparations was observed prior to insemination. Fertilization rate, cleavage rate and embryo quality were similar in both treatment and control groups. Nine out of ten pregnancies were achieved after the replacement of embryos both from the treatment and control group. Although pentoxifylline is known to enhance motility in-vitro and to promote induced acrosomal loss, its indiscriminate use failed to improve IVF performance in patients with anti-sperm antibodies. Further research may be necessary in order to elucidate whether a given subpopulation of these patients may benefit from a selective application of pentoxifylline.

Adult↗
PubMed1994

In vitro fertilization in couples with previous fertilization failure using sperm incubated with pentoxifylline and 2-deoxyadenosine.

OBJECTIVE: To evaluate whether incubation of spermatozoa with both pentoxifylline and 2-deoxyadenosine would improve fertilization rates in couples with previous IVF failure. DESIGN: Autocontrolled design in which sibling oocytes were inseminated at random in vitro with spermatozoa treated or not treated by pentoxifylline and 2-deoxyadenosine. MEAN OUTCOME MEASURES: Oocyte quality, sperm motility, fertilization in vitro, and embryo quality. RESULTS: Sperm motility was found optimized by metabolic stimulation using pentoxifylline and 2-deoxyadenosine. The mean fertilization rate per patient was 33.1% in the treatment group compared with 37.0% in the control group. The mean cleavage rate per patient was 79.6% for treatment versus 68.7% for control embryos. No differences in embryo quality were noted. CONCLUSION: The results of this study demonstrate that an indiscriminate use of pentoxifylline and 2-deoxyadenosine is not beneficial to fertilization in couples with previous IVF failure. Further prospective research may be needed to assess the benefit of pentoxifylline and 2-deoxyadenosine in patients selected by preliminary functional in vitro tests.

Adult↗
PubMed1994

Intracytoplasmic sperm injection.

Intracytoplasmic sperm injection (ICSI) is a promising assisted fertilization technique that may benefit women who have not become pregnant by in-vitro fertilization. ICSI and subzonal insemination (SUZI) were used to treat couples who failed fertilization after standard IVF or who could not be accepted for IVF because too few motile spermatozoa were present in the ejaculate. This paper describes the outcome of 750 consecutive cycles of SUZI and ICSI. Different aspects of these novel assisted fertilization procedures are described: patient management, ovarian stimulation, semen evaluation and treatment, oocyte collection and preparation, SUZI and ICSI techniques, assessment of fertilization and embryo cleavage, outcome of embryo transfers and the evolution of the pregnancies.

Embryo Transfer↗
PubMed1994

Incubation of spermatozoa from asthenozoospermic semen samples with pentoxifylline and 2-deoxyadenosine: variability in hyperactivation and acrosome reaction rates.

We examined hyperactivation and acrosomal loss in asthenozoospermic patients with a history of failed in-vitro fertilization (IVF). After selection by a Percoll gradient, spermatozoa were incubated with 3.6 mM pentoxifylline (PTX), 3.0 mM 2-deoxyadenosine (2-DXA) or both. Hyperactivation and ionophore A-23187-induced acrosome reaction were assessed immediately after sperm treatment and again after 180 min. In all groups studied, the mean hyperactivation rates were found to be low. No significant differences were noted between assessments immediately after treatment and 180 min later, except after treatment with both PTX and 2-DXA. The mean hyperactivation rates were found not to improve as a result of either PTX or 2-DXA, while the combination of both PTX and 2-DXA revealed a significant enhancement of total hyperactivation. When individual hyperactivation rates between control and treated sperm samples were compared, large differences in response were observed. Some sperm samples showed a marked increase in hyperactivation with one treatment, while another treatment led to a decrease. Acrosome reaction rates assessed immediately after ionophore A-23187 stimulation were found not to be significantly different from those assessed 180 min later. No significant effect could be demonstrated for either treatment, although, here too, marked interindividual variations were noted. It was concluded that an unselective use of PTX, 2-DXA or both compounds together, may restore sperm function in certain of these patients, and perhaps improve fertilization in vitro, but in others it may produce no change or may even be detrimental to sperm function.

Acrosome↗
PubMed1994

Auto-controlled study on in-vitro fertilization performance with 'antibody-free' spermatozoa selected by immunobead adsorption from semen of patients with anti-sperm antibodies.

Selection of antibody-free spermatozoa by immunobead adsorption was performed as a preliminary test in order to check probable recovery before introducing the procedure in an in-vitro fertilization (IVF) trial. On this basis, only nine out of 21 couples could be allocated to the study on IVF, which was designed to compare fertilization rates obtained with the immuno-selected spermatozoa fraction versus the control swim-up fraction. The study comprised eight properly controlled IVF procedures with sibling oocytes. Despite the high severity of antibody-binding in the fresh semen [mean of 91% for immunoglobulin (Ig) G, 77% for IgA], selection of antibody-free spermatozoa was successful in seven out of eight cases (mean of 15% for IgG, 20% for IgA). Nevertheless, mean fertilization rate on a per patient basis was not different after using one of the two sperm preparation procedures. Four patients had similar fertilization rates with the two sperm fractions, while for three patients fertilization was achieved only with the immuno-depleted fraction. In terms of embryo quality, similar results between the two groups were obtained. Two pregnancies were obtained, one was obtained with swim-up-prepared spermatozoa alone; the second, a twin pregnancy, originated from both the swim-up and immuno-depleted sperm populations. From this study, it can be concluded that the technique of immunobead adsorption itself seems attractive for the selection of antibody-free spermatozoa, but can be applied only to a limited population of patients (< 50%) suffering from immunological male infertility. Furthermore, in cases where immunodepletion seemed successful, no consistent benefit was observed in terms of IVF performance.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

An indiscriminate use of pentoxifylline does not improve in-vitro fertilization in poor fertilizers.

In order to enhance fertilization in vitro, pentoxifylline (PTX) was used in couples showing low fertilization rates in previous in-vitro fertilization (IVF) attempts for the treatment of male-factor infertility. Sibling oocytes were inseminated at random with spermatozoa prepared with or without PTX. After selection by Percoll gradient, sperm samples were divided into two equal aliquots. One aliquot was incubated in Earle's medium containing approximately 3.6 mM PTX (treatment group), the other aliquot was incubated with PTX-free Earle's medium (control group). After 30 min, both suspensions were washed twice. Sperm parameters after preparation did not differ between treatment and control samples, and nor did the mean fertilization rates, which were 49.3 and 42.6% respectively. Cleavage characteristics and morphological quality of the embryos were not significantly different between the treatment and control groups. The results of this study demonstrate that indiscriminate use of PTX in an IVF programme increases neither fertilization rate nor embryo transfer rate in poor fertilizers. More prospective research is needed to evaluate the role of PTX in IVF in couples selected according to the effect of the compound on sperm function, e.g. hyperactivation and acrosome reaction.

Adult↗