IVF success rates- how should these be measured and reported
Gab Kovacs (AU)
[Kovacs] Epworth Healtcare
IVF success rates- how should these be measured and reported? Introduction/ History The early IVF pregnancies were isolated miracles and were reported as “Case Reports”. Then as some units achieved a a few pregnancies, resultss were reported as small series. Pregnancy rates expressed as percentages, were quite meaningless, as the series were always small numbers of pregnancies. So what variables do we need to consider? For any equation there is a denominator and a numerator. What should be the denominator? • Patients commencing treatment • Patients commencing stimulation • Patients undergoing oocyte collection • Patients obtaining mature oocytes • Patients having embryos for transfer (normal embryos) • Patients undergoing embryo transfer What should be the numerator? . Patients with a positive βHCG > 30 • Patients with a clinical pregnancy • Patients with live deliveries • Patients with term live deliveries • Patients with singleton term pregnancies (BESST) One shot at pregnancy?-This is unrealistic. Lets look at multiple attempts. This can be undertaken by creating a “life table analysis”. This is a statistical analysis to allow for incomplete follow up. Should we categorise by variables that effect prognosis? The success rate will be influenced by the percentage of patients with good prognosis included in the denominator. • Number of embryos transferred. • Stage of embryo transfer. • Age. • Previous attempts. How do we consider “freeze all cycles?” Another complicated factor is the relatively new tendency of “freeze all” cycles, where embryos are frozen during the stimulated cycle, and then replaced in a subsequent cycle after cryopreservation and thawing. How do we express these? Should there be league tables? Conclusion There are many ways to express results, and consumers have great difficulty understanding what they mean.