Hyperactivated motility of human spermatozoa: a review of physiological function and application in assisted reproduction.
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Hyperactivated motility is a specific movement pattern which has been recognized in mammalian spermatozoa for over 25 years. During this time, it has been established that hyperactivation is part of the complex process of sperm capacitation, which is necessary before fertilization can occur. The recent introduction of computed sperm motility analysis has allowed detailed studies of sperm movement characteristics to be undertaken, and evidence is accumulating that hyperactivated motility may correlate with fertility. In this review, the physiological consequences of hyperactivated motility, methods of measurement and their application in assisted reproduction are discussed. (+info)
Inhibin A and inhibin B reflect ovarian function in assisted reproduction but are less useful at predicting outcome.
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To test the hypothesis that dimeric inhibin A and/or inhibin B concentrations represent improved markers of in-vitro fertilization (IVF) outcome over follicle stimulating hormone (FSH), 78 women who achieved pregnancy within three assisted reproduction treatment cycles were matched to 78 women who underwent at least three assisted reproductive treatment cycles and failed to achieve pregnancy. Baseline serum inhibin B and FSH were obtained between days 1 and 4 in a cycle prior to ovarian stimulation, and inhibin A and B were measured immediately before the ovulatory stimulus and in follicular fluid from the lead follicle. Comparing pregnant and non-pregnant subjects at baseline, younger age (34.0 +/- 0.5 versus 36.0 +/- 0.5 years; P < 0.003) and a combination of FSH lower than the median value (11.2 IU/l) and inhibin B higher than the median value (76.5 pg/ml) were associated with pregnancy (P < 0.03), but FSH (11.7 +/- 0.5 versus 12.9 +/- 0.9 IU/ml) and inhibin B (89.0 +/- 10.2 versus 79.7 +/- 7.7 pg/ml) were not independently associated. At the time of the ovulatory stimulus, serum inhibin A (52.8 +/- 3.8 versus 40.0 +/- 2.7 IU/ml; P < 0.004), inhibin B (1623.8 +/- 165.1 versus 859.2 +/- 94.8 pg/ml; P < 0.0009) and the number of oocytes retrieved (14.6 +/- 0.8 versus 10.1 +/- 0.6; P < 0.0001) were predictive of pregnancy when controlled for age. Inhibin A was correlated with the number of embryos (r = 0.4; P < 0.0001). However, neither inhibin A nor inhibin B provided additional information in predicting successful outcome over age and number of oocytes. We conclude that: (i) in patients undergoing assisted reproductive technology, age and number of oocytes retrieved are the strongest predictors of success; (ii) of the parameters available prior to cycle initiation, a combination of lower FSH and higher inhibin B was associated with a greater chance for a successful outcome but an absolute cut-off could not be defined; and (iii) during ovarian stimulation, higher concentrations of inhibin A and inhibin B in serum are associated with successful IVF and mark ovarian reserve as a measure of oocyte number and quality. (+info)
Klinefelter's syndrome in the male infertility clinic.
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The clinical features of patients with Klinefelter's syndrome attending a male infertility clinic have been investigated in order to consider their assisted reproduction treatment options. Over 12 years, a total of 148 patients with sterility due to azoospermia had Klinefelter's syndrome. Eight patients were shown by fluorescence in-situ hybridization (FISH) on metaphase spreads to be mosaic (46,XY/47,XXY), and 140 patients showed only 47,XXY. Small testes were observed in 95% of patients and gynaecomastia was seen in 12.4%. Half of the patients showed hypergonadotrophic hypogonadism, while others showed normogonadism (usually hypergonadotrophic). Spermatozoa were observed in semen from one patient with mosaicism and one without. Three-colour FISH revealed hyperploidy in 2.7% and 2.3% of these spermatozoa respectively. Multiple-site testicular biopsies in five recent patients were performed and yielded a specimen with round and elongated spermatids in one patient with 47,XXY karyotype. This sample was cryopreserved for future intracytoplasmic sperm injection. At follow-up, 46% of couples had chosen artificial insemination with donor sperm, and none had chosen adoption. Two patients developed testicular tumours, one a mature teratoma and the other a Leydig cell tumour. Two patients required androgen replacement therapy. (+info)
Comparative evaluation of two density gradient preparations for sperm separation for medically assisted conception.
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To evaluate and optimize the sperm separation efficiency of a novel silane-coated silica bead (Puresperm), serial studies were carried out to compare the various sperm parameters between: (i) three-layer (90%-70%-40%) Puresperm and three-layer (90%-70%-40%) conventional polyvinylpyrrolidone (PVP)-coated silica bead (Percoll) gradients; (ii) three-layer (90%-70%-40%) and two-layer (90%-45%) Puresperm gradients and separately the same for Percoll; and (iii) large (3.0 ml) and small (0.75 ml) semen loading volumes on three-layer Puresperm gradients. Normozoospermic semen samples were treated and analysed in 12 replicates for each experiment. Manual evaluation of concentration, percentage motility, percentage vitality, percentage normal morphology; computer-assisted semen analysis evaluation of concentration, percentage motility, grade of motility, motion characteristics (curvilinear velocity, linearity, amplitude of lateral head velocity, beat cross frequency, percentage hyperactivation); and yields from the initial semen samples were compared. Percoll was found to be superior to Puresperm in concentration, percentage motility, percentage vitality and yields after three-layer density gradient centrifugation. There were no significant differences in sperm parameters between two- and three-layer Percoll gradients, but three-layer Puresperm gradients behaved significantly better than two-layer gradients. Large semen volume loads on three-layer Puresperm gradients resulted in greater sperm concentrations, percentage motility, percentage vitality and percentage normal morphology, but small semen volume loads produced greater yields of good-quality spermatozoa. In the light of Percoll being withdrawn from the shelf for the use of assisted reproduction because of the presence of PVP, three-layer Puresperm gradients with large semen loading volumes appear to be an attractive alternative for sperm separation in medically assisted conception. (+info)
Precision and method bias of two assays for oestradiol: consequences for decisions in assisted reproduction.
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Oestradiol monitoring in assisted reproduction is empirical, with no proof of benefit. Precise oestradiol estimation will be an essential pre-requisite for high quality evaluation of possible differences between combined and ultrasound-only monitoring. Objectives of the present trial were independent method comparison and bias estimation of chemiluminescent immunoassay (CLIA) versus radioimmunoassay for oestradiol. In a prospective comparison, 505 consecutive samples were split and assayed concurrently. Precision (reproducibility), relative bias and logistics were analysed and compared to manufacturers' findings. Correlation between CLIA and radioimmunoassay was excellent. Positive bias with CLIA necessitated altering decision points for therapy. Precision (reproducibility) was superior with CLIA, making it an appropriate candidate method for future randomized trials of the effectiveness of combined oestradiol/ultrasound monitoring for assisted reproduction. (+info)
Clinical efficacy of spermatid conception: analysis using a new spermatid classification scheme.
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Fertilization and pregnancy outcomes of 50 round spermatid injection (ROSI) and 20 elongated spermatid injection (ELSI) treatment cycles are related to various characteristics of the cycles, with particular reference to spermatid developmental stage as assessed by using a classification scheme adapted to this purpose. Although this classification includes eight stages, a complete block was mostly detected at the earliest stage (Sa1) or at the latest stages (Sd1 and Sd2). Thus, spermiogenesis was blocked at Sa1 stage in 50 cases (71%), at Sd1 stage in eight cases (11%) and at Sd2 stage in 10 cases (14%). Only in two cases (3%) was spermiogenesis blocked at an intermediate stage (Sb2). Globally, fertilization rates were higher for ELSI than for ROSI. No pregnancy was achieved in the ROSI cycles, whereas nine pregnancies resulted from the ELSI cycles. Two of them (both with Sd2 spermatids) ended in a first trimester spontaneous abortion. Of the seven ongoing pregnancies, five are singleton (two with Sd1 spermatids, two with Sd2 spermatids, and one after a mixed transfer after injection of Sa2 and Sd1 spermatids) and two are twin (one with Sd1 and the other with Sd2 spermatids). No pregnancy was achieved in the two cycles with Sb2 spermatids. One of the two twin pregnancies has already resulted in the birth of two healthy children. (+info)
Attitudes towards reproduction in Latin America. Teachings from the use of modern reproductive technologies.
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The use of modern reproductive technology, such as in-vitro fertilization and its related procedures, has opened new areas of legal, religious and public concern. Thirty years ago, the development of effective methods to control procreation generated a debate on whether couples had the right to enjoy sex in the absence of its procreative effect. Today, assisted reproductive technology (ART) allows couples to have their own children in the absence of a direct intermediation of sex. The Catholic Church has reacted against both contraception and ART, and specific instructions have been directed to the public, the medical profession and legislators. In a recent survey, 88.4% of the population in Latin America claims to be Catholic; therefore, bioethical considerations and legal implications concerning intervention in reproduction are strongly permeated by the moral teachings of Catholicism. In 1996, 83 medical doctors and scientists, participating in the Latin American Network of Assisted Reproduction, produced a consensus document on ethical aspects and legal implications of ART. The document contains minimal ethical guidelines that Latin American professionals have decided to adhere to, even in the absence of legal regulations. This article examines how the medical profession, legislators and the public react to religious influence when confronted by difficult bioethical decisions such as the right to procreate. (+info)
Developmental and genetic disorders in spermatogenesis.
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The most common cause of male infertility is idiopathic. Fresh insights based on genetic and molecular analysis of the human genome permit classification of formerly unexplained disorders in spermatogenesis. In this article, we review new procedures that expand diagnostic and therapeutic approaches to male infertility. Recombinant DNA technology makes it possible to detect specific chromosomal and/or genetic defects among infertile patients. The identification of genes linked to disorders in spermatogenesis and male sexual differentiation has increased exponentially in the past decade. Genetic defects leading to male factor infertility can now be explained at the molecular level, even though the germ cell profile of infertile patients is too variable to permit classification of the clinical phenotype. Increasing knowledge of genes that direct spermatogenesis provides important new information about the molecular and cellular events involved in human spermatogenesis. Molecular analysis of chromosomes and/or genes of infertile patients offers unique opportunities to uncover the aetiology of genetic disorders in spermatogenesis. Increasing numbers of cases, previously classified as idiopathic, can now be diagnosed to facilitate the treatment of infertile men. Advanced knowledge also poses ethical dilemmas, since children conceived with assisted reproductive technologies such as intracytoplasmic sperm injection (ICSI) are at risk for congenital abnormalities, unbalanced complements of chromosomes and male infertility. (+info)