What is the most relevant standard of success in assisted reproduction?: challenges in measuring and reporting success rates for assisted reproductive technology treatments: what is optimal?

For assisted reproductive technology (ART) treatments, measures of success that move beyond traditional measures of pregnancy and live birth and narrow the numerator to infant outcomes with an optimal short- and long-term prognosis are needed. Hence, presentation of singleton live birth delivery rates is warranted. Twins have greatly increased risks for morbidity and mortality in comparison with singletons. Success rates based on singleton live births will more completely inform patients evaluating which ART treatment options will maximize their chance for a healthy infant. Additionally, providers who limit embryos transferred can feel they are on an even playing field in reporting their success rates. Measures of success that narrow the numerator further to exclude preterm or low birth weight singleton births might also be informative. However, the utility of such measures is less clear because the aetiologies of preterm birth and low birth weight among singletons are probably multifactorial. While it may be desirable to consider adverse outcomes such as congenital anomalies in defining treatment success, it is unfeasible to collect complete and accurate data on anomalies in current ART registries. As ART use increases, continual re-examination and critique of the manner in which success is defined and presented to the public is critical.