The chance of spontaneous conception for the infertile couple referred to an academic clinic for reproductive endocrinology and fertility in The Netherlands

892 infertile couples were studied retrospectively over a 4 year and 7 month period for their chance of spontaneous conception after first attendance at the clinic. The Kaplan-Meier method was used for all calculations. Most of the spontaneous conceptions took place within two years. As the age of the female patient increased, beginning at age 30, the cumulative spontaneous conception rate decreased. The same was true for the duration of infertility beginning at 4.5 years. The influence of the latter was more important. The cumulative conception rate was not influenced by whether the infertility was primary or secondary. Patients referred by a general physician had a better chance of achieving spontaneous conception than patients referred by a gynaecologist. It is concluded that time plays a significant role in the achievement of pregnancies in our clinic, but should no longer be relied upon two years after entering the clinic.