Impact of COVID-19 pandemic on assisted reproductive technology treatment under voluntary lockdown in Japan.

To investigate the impact of a state of emergency (i.e., voluntary lockdown) during the COVID-19 epidemic, we conducted a retrospective cohort study using the Japanese nationwide registry. In comparison with those during 2019, the number of treatment cycles decreased in April 2020 (-9.5%) to its lowest point in May (-24.1%). The magnitude of the decline was three times larger for frozen cycles (-37.0%) than for fresh cycles (-12.4%). The decrease was significantly smaller for women aged <35 years (-31.0%) than for the older groups (-39.0% to -39.7%). Under voluntary lockdown, a considerable decrease was observed especially for frozen cycles and older women.