Physical resolution of tubal ectopic pregnancy on ultrasound imaging following successful expectant management

Research question: What is the time required for complete physical resolution of tubal ectopic pregnancies diagnosed on ultrasound imaging in women undergoing successful expectant management? Design: A prospective observational cohort study of 177 women who had successful expectant management of tubal ectopic pregnancy, who attended a single Early Pregnancy Unit between January 2014 and December 2018. All participants were monitored until their serum beta-human chorionic gonadotrophin (beta-HCG) dropped to nonpregnant concentrations and with 2-weekly follow-up ultrasound scans until resolution of the pregnancy. Results: A total of 112/177 (63.3%, 95% confidence interval [CI] 55.7-70.4) of tubal ectopic pregnancies were indiscernible on ultrasound 2 weeks after serum beta-HCG had returned to non-pregnant concentrations. In 8/177 (4.5%, 95% CI 2.0-8.7), physical resolution took longer than 78 days. There was a positive correlation between biochemical and physical resolution of tubal ectopic pregnancy (r = 0.21, P = 0.006). Conclusions: Physical resolution of tubal ectopic pregnancy is often prolonged and is positively correlated with initial and maximum beta-HCG concentrations. Results of this study indicate that beta-HCG resolution cannot be used as the end-point of expectant management of tubal ectopic pregnancy, which should be considered when counselling women and planning for future pregnancies.