EP21.11: Factors that can guide follow‐up in women diagnosed with pregnancy of unknown viability

Bleeding and/or pain are common symptoms indicating the need for a transvaginal ultrasound scan (TVS) and the finding of a pregnancy of unknown viability (PUV) can cause anxiety due to uncertain prognosis. The aim of this study was to ascertain whether gestational age at presentation, interval between first positive urine pregnancy test (UPT) and TVS, or presenting symptoms could guide presence of follow up. A retrospective cohort study was conducted between 01/07/2023 to 31/12/2023 at a large university teaching hospital in London, UK. All pregnant women attending our emergency gynecology clinic underwent a TVS to assess the viability of the pregnancy, all women with a diagnosis of PUV on the first scan were included in the study. We excluded women who had fertility treatment or irregular cycles or incomplete data. Multivariate regression model was used to analyse the data. A p-value of <0.05 was considered statistically significant. 159 women were diagnosed with PUV. Of these, 72/159 (45%) ended in a miscarriage. Pregnancies of advanced gestational age diagnosed as PUV were more likely to end in a miscarriage than those presenting at an earlier gestation (p < 0.01). However first positive UPT date to TVS date interval did not show a significant correlation for miscarriage (p = 0.14). Presence of bleeding was more likely to result in a miscarriage (OR 5.9; p < 0.01), whereas pain and history of miscarriage did not reach statistical significance to show an increased association for PUV to end in miscarriage (OR 1.0, p = 0.99; OR 0.7, p = 0.44 respectively). The prevalence of miscarriage in PUV was 45%. Gestational age at scan and symptoms can be used to guide follow up and counselling of patients diagnosed with PUV.