Proposal for Diagnostic Criteria of Y-Shaped Dysmorphic Uterus Based on 3-Dimensional Transvaginal Ultrasound Measurements

Study Objective: To define objective and readily applied diagnostic criteria for Y-shaped uteri using 3-dimensional transvaginal ultrasound (3D-TVUS) volume recordings.

Design: A retrospective case-control diagnostic measurements study.

Setting: A tertiary university hospital's reproductive health and research center.

Patients: Two hundred thirteen patients who presented with infertility between January 2020 and December 2022.

Interventions: Two blinded physicians re-evaluated the 3D-TVUS images of all patients for the presence of a uterine abnormality. The images of patients with a Y-shaped uterus were re-evaluated, and descriptive measurements were done.

Measurements And Main Results: The most common uterine abnormality in this cohort was the Y-shaped uterus with a prevalence of 12.2%, followed by the arcuate, T-shaped, and septate uteri, respectively. Reviewers identified 26 and 28 Y-shaped uteri, respectively, and came to a consensus on 25 images. Diagnostic criteria for the Y-shaped uterus based on 3D-TVUS findings have been specified as: lateral indentation depths between 4 and 7 mm, fundal indentation depth between 5 and 9 mm, lateral indentation angles between 121° and 149°, fundal indentation angle between 121° and 145°, and Y-angles 25° to 46°.

Conclusion: Some subtypes of dysmorphic uteri, such as the Y-shaped uterus, whose clinical significance is unknown and may be variants of the normal, may actually be more common than thought. Determining objective diagnostic criteria with 3D-TVUS will allow standard research on these anomalies and their clinical significance.