VP62.18: Ultrasonographic changes of deep endometriosis nodules and endometriomas before and after pregnancy

During pregnancy the appearance of endometriotic lesions may be impacted by changes in hormonal environment. This study aims to explore the impact of pregnancy on ultrasonographic features of deep endometriosis (DE) and endometriomas (OMA). This prospective study included spontaneous pregnant patients with a previous diagnosis of endometriosis at transvaginal ultrasound. Patients did not have received hormonal therapies for endometriosis for at least 3 months before the last ultrasound assessment of endometriosis. The characteristics of endometriotic nodules were compared between the evaluation performed before conception and that performed at 40-60 days after delivery by a single experienced sonographer. The DE lesions were evaluated in five locations (uterosacral ligament, vagina, bladder, rectovaginal septum, and rectosigmoid). Changes in the volume were assessed by using the virtual organ computer-aided analysis (VOCAL). A total of 57 patients (86 DE lesions; 34 OMA) were included; the mean ( ± SD) age of the study population was 33.6 ( ± 3.4). The mean overall volume of DE nodules did not significantly change before pregnancy compared to after pregnancy regardless of their localisation (2.55 ± 3.81 cm3 vs. 2.43 ± 3.13 cm3; p = 0.31). The mean volume of the largest nodule of each patient did not significantly change (3.23 ± 4.78 mm3 vs. 3.07 ± 4.89 mm3; p = 0.18). The volume of DE nodule decreased in 20.9% (n = 18/86), was stable in 74.4% (n = 64/86) and increased in 4.6% (n = 4/68) of cases. The volume of OMA was significantly higher before pregnancy (3.41 ± 3.14 mm3 vs. 2.45 ± 3.32 mm3; p < 0.001). The ultrasonographic appearance of DE nodules and endometriomas did not significantly change. No complications related to endometriosis were observed during the pregnancies. During pregnancy, women with endometriosis do not have a substantial change in features of DE lesions, although they have a significant decrease in OMA size.