This study aims to enhance the understanding of how the increasing use of assisted reproductive technologies (ART) has contributed to the increase in the total fertility rate (TFR) and to further delaying childbearing. Moreover, it addresses the gap in the methodology concerning the quantification of the effect of ART on fertility postponement. Czechia is one of few countries that are able to serve for the study of the demographic impacts of ART. ART and non-ART fertility rates were calculated using unique data on all children born in Czechia. Excluding mothers who received cross-border reproductive care, the proportion of ART live births in Czechia has not exceeded 4%. However, without ART the TFR would have stood at just 1.65 instead of 1.71 in 2020. ART significantly contributed to a reduction in childlessness and to the increase in fertility rates at ages over 35. Applying the decomposition method, the contribution of the use of ART to delaying childbearing between 2013 and 2020 was 4%. The findings have important policy implications. ART has the potential to support fertility recovery in the context of delayed childbearing. The findings served to alleviate concerns about the contribution of ART to the further undesired delay of childbearing.