PIP: When cervical injury follows induced abortion, it usually occurs during dilatation. This article presents data comparing the effects of laminaria and Hegar dilators on the internal os. 87 unmarried primigravidas in the 1st trimester of pregnancy were studied; in 1 group Hegar dilatation and suction evacuation of the uterine cavity were performed, with the diameter of the internal os measured by Hegar dilators and in the 2nd group 1 small-size laminaria tent was used, with the diameter measured first. The mean preoperative diameter of the internal os was wider (p0.002) in group 1, with the mean cervical diameter of group 2 significantly smaller (p0.001). 3 complications occurred in the Hegar dilatation group and in the laminaria group 4 women required additional Hegar dilatation to 10 mm after removal of the laminaria. The larger diameter at dilatation of the Hegar group as opposed to the laminaria group indicates more trauma to the internal os. These data suggest that induction of early abortion by use of laminaria for dilatation is less traumatic than the use of rigid dilatation.