The clinical impact of in-vitro fertilization. Part 1. Results and limitations of conventional reproductive medicine.

Conception is a matter of chance. A couple's monthly probability of conceiving naturally is known as their fecundability. The average "normal" fecundability (as a proportion) is approximately 0.2. This means that most young couples can expect to have children and will conceive within 12 months of attempting pregnancy. This article examines the causes of infertility and the results that can be achieved by conventional treatment among couples with a single cause for their infertility. The difficulties that are faced when conventional infertility treatment is applied to infertility with multiple causes or with no apparent cause are explained.