ABSTRACT
Objective To evaluate and analyse the morphological structure in late pregnancy women of pelvic hiatus by appli-cation of transvaginal three-dimensional ultrasound .Methods The 60 cases pregnant women who were checked pregnant weeks for 31 to 40 weeks from January 2012 to December 2014 came to our hospital were chosen as the observation group ,and other 60 cases women who were nulliparous women because of irregular menstruation at the same period treatment as control group .All patients underwent transvaginal three-dimensional ultrasound examination by observed the morphological structure of pelvic hiatus in each period ,and the research object of pelvic hiatus left and right diameter ,anteroposterior diameter and area were compared and meas-ured between the two groups .Results (1)The normal pelvic hiatus morphology was rhombic column crack-like structure ,but the observation group who had 43 .33% abnormal pelvic hiatus morphology and there was kind oval ;(2)The observation group were pelvic diaphragm hiatus of left and right diameter ,anteroposterior diameter and area were significantly larger than the control group in three conditions of the resting period ,anal contraction period and tension period ,and the difference was statistically significant(P< 0 .05) ;all the research object of the pelvic diaphragm hiatus left and right diameter ,anteroposterior diameter and area were de-crease in the anal contraction and increases in tension period for compared with the resting period ,so the difference was statistically significant (P< 0 .05) .Conclusion The three-dimensional ultrasound can be clearly observed the morphology of the female pelvic diaphragm hiatus ,and can be effectively evaluated .The late pregnancy women who will be significantly increases of pelvic dia-phragm ,occurs the relaxation phenomenon and some abnormal morphology for compared with nulliparous women .