Introduction. The evaluation of a tumor’s aspect in case of an expansive ovarian neo-formation is a controversial chapter in the specialized literature. For most practitioners it causes uncertainties in the management of both gynecological and obstetric patients. Aim of the study. Getting practitioners acquainted with helpful logical instruments, elaborated for optimizing the differential pre-operatory diagnosis of the ovarian tumors during pregnancy. Materials and methods. This research represents the analysis of the results collected from 35 pregnant women diagnosed, who got a surgery for ovarian cysts during pregnancy. In each case, pre-operatory, the ultrasound characteristics of the ovarian tumors have been modulated and analyzed by a computer together with the clinical data and serological results of tumoral markers. The results were compared with the histological data. The logical instruments analyzed during the research were the ultrasonography Sassome score, the Pelvic Mass Score(PMS), and the IOTA model. For a better estimation of the specificity and sensibility of the diagnostically method, “borderline“ ovarian tumoral formations were considered malignant. Results. The Sensibility(S) and specificity(s) of the tests analyzed during the research are almost similar with the results displayed by the specialized literature: the ultrasonography Sassome score (PMS) : S - 96%; s - 70%; IOTA models: S - 97%; s - 80%. The results from the ovarian formations histological analysis are: n=35 anatomic surgical pieces, in 19 cases (54%) simple cystadenomas or mixt sero–mucinous cysts were confirmed, 6 cases (17%) were ovarian teratomas containing embryonal tissues; other 4 cases, 11% were functional cysts such as theca luteal cysts and cysts of the yellow body; in other 3 cases (9%) endometrial cysts were found; 2 cases (6%) were borderline tumors. In one case (3%), ovarian cancer was confirmed using histological and imagistic tests. Conclusions. Evaluating different methods of diagnosis, we have assessed their high sensibility and specificity, and a better prognosis in ovarian tumors, facts confirmed by literature data. Further studies are necessary to be done, to estimate the utility of different methods of diagnosis of ovarian tumors in pregnancy, all of them having a huge role in decision making about surgical or expectative management. The use of the tests is not expensive and can be easily applied in everyday practice for strengthening the diagnostic methods at the moment of choosing an appropriate treatment approach.