The pregnant uterus usually shows some degree of torsion during the latter half of pregnancy. Such torsion is merely an exaggeration of the physiologic rotation of the pregnant uterus. This usual type of rotation is readily seen at laparotomy, especially at term. It consists of a longitudinal twist of a few degrees. The twist is to the right in 80 per cent of patients and to the left in only 20 per cent. Torsion of this type has no major clinical significance.
True axial rotation of the pregnant uterus is rare and serious. Sudden rotation of the uterus on its long axis through more than 90 degrees may result in premature separation of the placenta, hemorrhage, profound shock and the symptoms of acute peritonitis. When it occurs, it is usually in association with uterine tumors or malformations.
Robinson and Duvall1 have stated that "without uterine abnormalities there can be no
Reis RA, Chaloupka AJ. AXIAL TORSION OF A FULL-TERM PREGNANT UTERUS. JAMA. 1935;104(23):2080-2082. doi:10.1001/jama.1935.92760230001009