Management of male-factor infertility.

For many years, the management of male-factor infertility has been empirical rather than evidence-based. In current clinical practice, assisted reproductive techniques are the most successful methods of alleviating male-factor infertility. To date, it remains unclear what adjuvant actions can be taken to improve the outcome of assisted reproductive techniques for male-factor infertility. Evidence shows that smoking adversely affects sperm quality to some extent, and the genetic make-up of sperm to a greater extent; however, because of the scarcity and heterogeneity of studies, its effect on in-vitro fertilisation outcome remains largely unknown. Although smoking cessation should be part of the assisted reproductive techniques treatment plan, the benefit of antioxidant treatment in either smokers or non-smokers undergoing assisted reproductive techniques is still under scrutiny. Other lifestyle modifications in subfertile men, such as refraining from moderate alcohol and caffeine consumption, are even more controversial. When embarking on assisted reproductive techniques to alleviate male-factor infertility, intrauterine insemination may be considered as a first-line treatment for couples in whom the female partner has a normal fertility status, and at least 0.8 × 10(6) progressively motile spermatozoa are recovered after sperm preparation. If no pregnancy is achieved after three to six cycles of intrauterine insemination, in-vitro fertilisation can be proposed. When too few progressively motile spermatozoa are obtained after sperm processing for in-vitro fertilisation, or when surgically retrieved sperm are to be used, intracytoplasmic sperm injection is preferable. Although the outcome of no other assisted reproductive techniques has been scrutinised so much, and no large-scale 'macro-problems' have yet been observed after intracytoplasmic sperm injection, malformation rates are reported to be higher compared with the general population. Therefore, candidates for intracytoplasmic sperm injection should be rigorously screened before embarking on in-vitro fertilisation or intracytoplasmic sperm injection, and thoroughly informed of the limitations of our knowledge on the hereditary aspects of male infertility and the safety aspects of assisted reproductive techniques. Published by Elsevier Ltd.