EP24.02: Development of deep endometriosis following acute hemoperitoneum: a prospective ultrasound study

To determine whether acute hemoperitoneum which is managed conservatively is a precursor of deep endometriosis. This was a single-centre prospective observational cohort study conducted between August 2019 and March 2022. All non-pregnant, premenopausal women aged 18-50 years, who consecutively presented to our gynecological diagnostic unit with severe acute lower abdominal pain, were clinically stable and suitable for conservative management were included. Prior history or evidence of endometriosis on the initial ultrasound scan, previous hysterectomy or bilateral oophorectomy formed the exclusion criteria. Participants had standardised follow-up for six months, with transvaginal scans and pelvic pain questionnaires at each visit. Outcomes included sonographic evidence of newly formed endometriosis and the presence and change of pelvic pain symptoms and quality of life. There were 7/15 (47%; 95% CI 21.3–71.4%) women presenting with acute hemoperitoneum who developed sonographic evidence of deep endometriosis, compared to 0/36 (0%; 97.5% CI 0.0–9.7%) women without hemoperitoneum. The most common cause of hemoperitoneum was a ruptured functional hemorrhagic cyst, occurring in 13/15 women (87%). The EQ-5D scores at baseline were lower in the endometriosis group compared to the 'no endometriosis' group [-0.01 (IQR -0.07–0.19) vs 0.62 (IQR 0.24–0.73), P = 0.002)]. At six months, these scores improved in both groups, but remained significantly lower in the endometriosis group [0.69 (IQR 0.66–0.80) vs 0.85 (IQR 0.76–1.00), P = 0.03]. EQ-VAS and pelvic pain scores did not show clinically relevant differences. Our study supports a previous pilot study in demonstrating that significant hemoperitoneum could be a precursor of deep endometriosis. We suspect that endometrial cells trapped under blood clots may play a role. Larger studies are required, to investigate preventative treatments such as laparoscopy and pelvic washout, or ovulation suppression, and to assess women's symptoms and quality of life over a longer time period.