A method for statistical topographic recordings in the abdomen has already been presented (OHLSON 1972). This included a two-dimensional coordinate system based upon the constancy of certain skeletal reference points. The displacement of the ovarian artery in pregnancy was recorded in this system in order to test the usefulness of the method; the course of the artery changed with a distinct regularity, and the displacements were significantly different on the right and left sides. A subsequent investigation was directed to the anatomy of the ovarian artery and vein as well as of the ureter in the non-pregnant state correlated to the findings at dissection (OHLSON 1973). The asymmetric position of the aorta and the asymmetry of the para-aortic structures were reflected in the course of the ovarian artery, whereas the retroperitoneal space lateral to the para-aortic division, including the ovarian vessels and the ureters, was symmetric. This also implied that in the non-pregnant state the asymmetric anatomy of the abdominal organs was not reflected by the course of the ovarian vessels or ureters.The present investigation was concerned with the primary expansion of the pregnant uterus as reflected by the course of the ovarian vessels and the ureters