In vitro fertilization for male infertility: when and how?

The first observation that in vitro fertilization (IVF) was useful for treating oligozoospermia and oligoasthenozoospermia was reported by Fishel and Edwards in 1982. This was followed by a series of cases indicating the value of IVF in such cases. Conventional IVF has been modified and refined to achieve increased rates of conception in cases of male factor infertility. Methods such as high insemination concentration IVF for the treatment of teratozoospermia and microscopic IVF for the treatment of oligozoospermia have had some impact on fertilization and pregnancy rates; however, reports of success are varied. The recent advent of micromanipulation and, in particular, intracytoplasmic sperm injection (ICSI) has overshadowed the use of these modified IVF procedures. Because of the high fertilization and pregnancy rates achieved with ICSI, other micromanipulation techniques (subzonal insemination and partial zona dissection) have been abandoned; there have also been suggestions that other more conventional techniques, i.e. IVF, should also be abandoned and that ICSI become the sole technique for the treatment of infertility. The rapid increase in the number of centres using ICSI has led to extreme pressure for individual units to achieve high fertilization and pregnancy rates and there is a temptation to assign all patients to ICSI treatment. It is important that, in this highly competitive environment, new techniques are not applied haphazardly and reduced to the mere injection of gametes and achievement of pregnancy regardless of the cause of infertility. In his 1986 IVF--Historical Perspective, Fishel quoted Auguste Comte: 'to understand science it is necessary to know its history'. IVF has much recent history in animal and also human work. Although ICSI is the most significant therapeutic advance in male infertility treatment, its application to human IVF is only 4 years old, with a paucity of animal studies on which to rely. For this reason IVF still plays a very important role in the treatment of male factor infertility and should only be ruled out when it has failed previously or the number of available sperm is limited.