[The evaluation of ovarian tumor associated with pregnancy by the ultrasonographical method and serum CA125 levels].

We examined and evaluated ovarian tumor during pregnancy using ultrasonography. The CA 125 level was measured in 21 cases in the first and second trimesters. For a total of 65 cases of ovarian tumor considered to be tumor-like lesions (corpus luteum cyst, etc) the longitudinal and transverse diameters were measured, and the shape was assumed to be ellipsoid. Disappearance of the tumor was confirmed in 40 of the 65 cases. The disappearance occurred by the 16th week of gestation (mean time = 13 weeks and 2 days) in 32/39 (82%) cases, and the maximum diameter (size) did not exceed 10cm (50cm2) at any gestational week. Also the diameter (size) did not exceed 7cm (30cm2) after 15 weeks of gestation in the tumor-like lesions. Surgery performed during pregnancy (9-24 weeks) in 22 cases revealed 19 tumors (16 benign, one borderline malignant and two malignant tumors). The remaining 3 were chocolate cysts and did not require surgery because the diagnosis had been confirmed before pregnancy. There was no difference in the CA 125 level in benign and malignant tumors (15 were benign, 3 were chocolate cysts, one was borderline malignant and two were malignant tumors). Cases in which the maximum diameter (size) of an ovarian tumor increases or remains unchanged during the gestational period may need surgery for benign or occasionally malignant ovarian tumors.