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

ObjectiveTo measure IVF effectiveness, which is defined as the cumulative incidence of live delivery over real time in women after commencing IVF treatment.DesignPopulation-based retrospective cohort study.SettingIVF 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.