Cryptorchidism and its impact on male fertility: a state of art review of current literature

摘要

Cryptorchidism is associated with impairment of germ cell maturation and subsequent infertility in adulthood. The present report details common scenarios of referral of men with prior history of cryptorchidism and orchidopexy seeking advice for infertility, and examines the association between cyrptorchidism and male infertility. The increase in the understanding of the hormonal profiles and patho-physiological changes in germ cell maturation in cryptorchid boys may potentially change our approach and management strategies. Improvement in sperm retrieval techniques and micromanipulation techniques, such as intracytoplasmic sperm injection, has led to excellent fertilization and pregnancy outcomes of treatment cycles. Cryptorchidism or undescended testis is one of the most common congenital conditions in the pediatric population. The prevalence of cryptorchidism in full-term newborns ranges between 1% and 3%, while in premature boys it is reported to be as high as 30%. 1 Impairment of germ cell maturation and subsequent infertility in adulthood are well-recognized consequences of cryptorchidism. The incidence of azoospermia in unilateral cryptorchidism is 13% and this figure increases to 89% in untreated bilateral cryptorchidism, making cryptorchidism the most common etiologic factor of azoospermia in the adult. 2 Reports have suggested that orchidopexy be performed before 1 year of age to minimize germ cell loss as fertility index (number of spermatogonia per tubule) is adversely affected in boys with cryptorchid testes beyond a year. 3 , 4 Over the past decade, the rapid development of novel management approaches for male factor infertility has enabled many of these men, previously believed to be infertile, the ability to become fathers. Infertility or subfertility affects 15% of couples in Canada, and about 50% of fertility problems are attributed to a male factor. Of these men, testicular failure or non-obstructive azoospermia is the predominant component. Testicular spermatozoa can be retrieved in some non-obstructive azoospermia men despite the absence of ejaculated spermatozoa in their semen, for instance in cryptozoospermic men (intermittent detection of spermatozoa in ejaculate) due to isolated foci of active spermatogenesis. Further improvement in sperm retrieval techniques has allowed infertile couples to become engaged in the discussion of their potential for fertility. Micromanipulation techniques, such as intracytoplasmic sperm injection (ICSI) applied to sperm and ova in vitro (in-vitro fertilisation [IVF]), allow sperm with limited intrinsic fertilizing capacity to produce viable embryos. Since the introduction of microsurgical sperm retrieval and ICSI as accepted treatments for the azoospermic man, many studies have reported excellent fertilization and pregnancy outcomes of treatment cycles. The present report details 2 common scenarios of referral to our tertiary care fertility clinic of men with prior history of cryptorchidism and orchidopexy seeking advice for infertility.