How effective is in vitro fertilization, and how can it be improved?

Objective: To measure IVF effectiveness, which is defined as the cumulative incidence of live delivery over real time in women after commencing IVF treatment. Design: Population-based retrospective cohort study. Setting: IVF clinics in Western Australia (WA). Patient(s): All women ages 20-44 years inclusive at start of treatment, commencing IVF in 1982-1992 and 1993-2002 at clinics in WA (n = 8,275). Intervention(s): Data on IVF cycles were extracted from hospital records and a statutory reproductive technology register and linked to records of births. Main Outcome Measure(s): Cumulative incidence of an IVF-attributed live delivery and cumulative incidence of an IVF-attributed or IVF treatment-independent live delivery. Result(s): IVF effectiveness in the 1993-2002 cohort was 47% overall. It was highest in women ages 20-29 years at the start of treatment, measuring 58%; and 79% with the inclusion of IVF treatment-independent deliveries, and declined to 22% and 33%, respectively, in women ages 40-44 years. Couples underwent, on average, only three cycles, even though the cumulative probability of a live delivery increased with each successive cycle for at least the first five cycles. Conclusion(s): IVF effectiveness could be improved if women, particularly those over 35, underwent more cycles. (Fertil Steril (R) 2011;95:1677-83. (C)2011 by American Society for Reproductive Medicine.)