The declining efficiency of IVF in the USA.

study questionHas the efficiency of IVF cycles in the USA declined between 2012 and 2021? SUMMARY ANSWER: National U.S. data show a continuous linear decline in IVF cycle efficiency between 2012 and 2021. WHAT IS KNOWN ALREADY: Previous studies reported that live birth rates after IVF increased until 2010 but subsequently declined, potentially due to the introduction of IVF 'add-ons' and changes in clinical practice. STUDY DESIGN SIZE DURATION: Retrospective cohort study, using publicly available national U.S. IVF outcome data reported annually to the Centers for Disease Control and Prevention (CDC) for the period 2012-2021. PARTICIPANTS/MATERIALS SETTING

methodsCDC annual reports were used as a data source. Extracted variables included a number of IVF cycle starts, embryo transfers, embryo banking cycles, and live births. IVF 'treatment efficiency' was calculated as the proportion of live births per initiated cycle (intent-to-treat analysis). MAIN RESULTS AND THE ROLE OF CHANCE: Over the study period, IVF cycle starts increased by 234.7% (176 274 to 413 776), embryo transfers by 150.3% (134 471 to 202 121), and embryo banking cycles by 902.3% (18 585 to 167 689). Live births increased by 179.2% (51 286 to 91 906). However, cycle efficiency declined from 29.1% in 2012 to 22.2% in 2021, a relative reduction of 23.4%, with an approximately linear decline across the decade. LIMITATIONS REASONS FOR CAUTION: The study is based on aggregate CDC data without patient-level granularity. Therefore, analyses could not control for confounding factors such as parity, infertility diagnosis, or detailed age subgroups. Embryo banking practices also complicate year-to-year comparisons of live birth rates. WIDER IMPLICATIONS OF THE

findingsThese findings suggest that despite substantial growth in IVF cycle numbers, treatment efficiency has progressively declined in the USA over the last decade. This decline coincided with a rapid increase in the use of embryo banking and other IVF 'add-ons'. The results raise concern about current clinical practices and highlight the need for critical re-evaluation of routine interventions in IVF. STUDY FUNDING/COMPETING INTERESTS: No external funding was received for this study. NG and DHB hold patents related to androgen treatment in females (DHEA) with numbers US8067400B2, US8501718B2, and US9375436B2 (listed in USPTO/public records and assigned to American Infertility of New York). They also receive royalties from Nutraceuticals LLC, which has helped commercialize DHEA as a nutritional supplement. TRIAL REGISTRATION NUMBER: N/A.