Male Infertility: Diagnosis and Treatment PDF

Preface

Physicians dealing with childless couples are well aware of the high incidence of male infertility. Recent estimates indicate that a male factor is present in up to 40–50% of cases consulting for infertility. While the causes of male infertility are multiple, the therapeutic options have traditionally been more limited. Urological and medical interventions have been, and continue to be, successfully implemented in defined clinical scenarios. But, undisputedly, the explosive growth and efficiency of assisted reproductive technologies (ART) has changed the direction of the field of andrology.

Without any doubt, the development of intracytoplasmic sperm injection (ICSI) constituted a significant advancement not only in the treatment of infertility but also in nurturing further development of the discipline of clinical andrology. As a microtechnique to assist fertilization, ICSI has allowed men with severely compromised semen parameters (patients with oligo-astheno-teratozoospermia, alone or in combination, presenting with antisperm antibodies and even with obstructive or non-obstructive azoospermia) to achieve their desire to establish a family.

Spermatozoa are highly differentiated cells that have an essential function to fertilize the oocyte, leading to embryo development. Functionally competent sperm cells are the result of the complex processes of spermatogenesis that involve cell differentiation, multiplication (mitosis), acquisition of the haploid stage (meiosis) and a dramatic metamorphosis (spermiogenesis). Spermatozoa are released into the epididymis (spermiation), where further maturational, structural, biochemical and functional changes (capacitation) take place. Gametogenesis and seminiferous tubule functions occur under strict endocrine and paracrine control. To fertilize the oocyte successfully, the spermatozoon must be able to perform the critical functions of migration, recognition and binding to the zona pellucida, penetration of the zona pellucida, binding to the oolemma, activation of the oocyte, nuclear decondensation and participation in pronuclear formation leading to syngamy. This complex sequence of events leads to multiple potential opportunities for errors and interference by a multitude of pathogenic mechanisms.

Current treatment options for male infertility include a large number of urological procedures (reconstructive surgery in cases of ductal obstruction, correction of varicocele and others), medical– pharmacological interventions (use of hormones, antibiotics), low-complexity assisted reproductive procedures (such as intrauterine insemination therapy) and the more advanced and complex ART. However, despite that contemporary therapies have enhanced the opportunities for conception in couples suffering from male infertility, often these solutions are raised in the absence of a defined etiological or pathophysiological diagnosis. Male infertility is unfortunately still considered ‘idiopathic' in a large proportion of cases.

The first in vitro fertilization (IVF) child in the world, Louise Brown, was born in Bourn Hall, UK in 1978. She was followed by the first IVF birth in Australia in 1980; in Norfolk, USA in 1981 (Elizabeth Carr); in continental Europe in 1982; and in 1984 in Tygerberg, South Africa (reviewed in Fauser and Edwards 2005)¹. Since the early 1980s, the efficiency of IVF has improved dramatically, with clinical pregnancy rates per transfer cycle increasing from the mid-teens to 30–50%, according to the individual prognosis group. This accomplishment has been achieved by continuing efforts resulting in improved ovarian stimulation protocols, optimized gametes and embryo in vitro culture conditions, superior techniques of oocyte retrieval and embryo transfer, and development of more efficient embryo cryopreservation programs.