Research QuestionWhat is the value of 3D ultrasonography in the diagnosis and assessment of Asherman syndrome? DesignA prospective, study conducted in a hysteroscopy centre. ResultsA total of 685 subjects were recruited, 65 subjects dropped out and 620 were finally enrolled and analyzed. The overall sensitivity, specificity, and accuracy of 3D-TVS in the diagnosis of Asherman syndrome were respectively 95.7%, 80.7%, and 93.5%, the sensitivity and accuracy were significantly higher than that of 2D-TVS (P<0.001). The likelihood of 2D-TVS missing a case of mild IUA is 43.7%, compared with only 6.2% when 3D-TVS is used. The frequency of involvement in each anatomical area by adhesions in decreasing order were as follows: right and left uterine side walls (both 80%), central or mid-cavity (31%)), R cornual region (26%), L cornual region (23%), fundal wall (15%) and isthmus (4.5%). The correlation between 3D-TVS and hysteroscopy in each of the seven anatomical areas were separately analyzed. The results showed good agreement with regard to the three uterine walls (fundus, left lateral and right lateral), with Kappa values ranging from 0.68 to 0.81. The likelihood of the IUA being severe in nature when there were five or more areas, three or four areas, and one or two areas were 82%, 37% and 6% respectively (p<0.001). ConclusionsThe diagnostic value of 3D-TVS is higher than that of 2D-TVS. In clinical practice, whenever possible, 3D-TVS should replace 2D-TVS as the initial method of assessment to decide if hysteroscopy is necessary and to help with planning of the surgery.