Application of ICSI for cryptorchid therapy.
Recent advances are provided in assisted reproductive technology and application of ICSI as treatment for infertile patients with previous cryptorchidism. Fertility rates were 25-81% and 8-48% in patients with unilateral and bilateral cryptorchidism, respectively. With the advent of assisted reproductive technology, pregnancy was not possible without sperm. Research in humans has resulted in pregnancy and live births after the injection of haploid germ cells (round spermatids) into the oocytes. In the mouse tetraploid germ cells (primary spermatocytes), nuclei have been injected into oocytes, which undergo meiosis, forming an embryo and live young. In animal models, round spermatids from both cryptorchid and previously cryptorchid testes can initiate normal embryo development when injected into mature oocytes. These cells may be used as substitutes for mature sperm. However, cryptorchidism in humans is often associated with inherent defects of spermatogenesis. With successive breakthroughs in treatment of impaired fertility associated with cryptorchidism, there is an increased risk of genetic abnormalities in the progeny. It is incumbent on clinicians who are involved in reproductive medicine to proceed cautiously with the development and application of assisted reproductive techniques to avoid creating future generations of genetically abnormal individuals.
Sasagawa
I
I
Department of Urology, Yamagata University School of Medicine, Japan. isasaga@med.id.yamagata-u.ac.jp
Nakada
T
T
Yanagimachi
R
R
D003456:Cryptorchidism / Q000150:complications / Q000628:therapy*; D006801:Humans; D007248:Infertility, Male / Q000209:etiology / Q000628:therapy*; D008297:Male; D020554:Sperm Injections, Intracytoplasmic