Van Eekelen R, et al. - Researchers investigated the natural conception rate over the course of 12 months in couples with unexplained or mild male subfertility who are scheduled for fertility treatment and have a predicted unfavourable prognosis for natural conception. The natural conception rate over the course of 12 months was estimated to be 24.5% in couples who were allocated to treatment. Thereby suggesting that the couples who are about to start fertility treatment, still have about a one in four chance of ongoing pregnancy due to natural conception over 12 months.