ASRM uterine septum guideline

Diagrams of the ASRM definitions of normal/arcuate (A), septate (B), and bicornuate (C) uterus based on assessment of available literature, understanding that these anomalies reflect points on a spectrum of development.
(A) Normal/arcuate: depth from the interstitial line to the apex of the indentation <1 cm and angle of the indentation >90 degrees.
(B) Septate: depth from the interstitial line to the apex of the indentation >1.5 cm and angle of the indentation <90 degrees.
(C) Bicornuate: external fundal indentation >1 cm. Internal endometrial cavity is similar to a partial septate uterus.