Are the new 2023 ACR/EULAR classification criteria suitable for advancing the knowledge of obstetric antiphospholipid syndrome?

• The new 2023 ACR/EULAR classification criteria represent an overall advance for research in antiphospholipid syndrome (APS). • To achieve high specificity, in some domains such as obstetric morbidity, the most frequent clinical manifestations such as early and late fetal deaths, have lost significant classification value. • The lower classification value of antiphospholipid antibodies of the IgM isotype may also have an important impact on patients with obstetric APS. • Several recent studies unequivocally point out the impact on the sensitivity of the new criteria, especially in the obstetric domain. • This study underscores the importance of distinguishing between classification and diagnostic criteria and emphasizes the therapeutic implications of this differentiation in obstetric APS.