Utility of βhCG monitoring in the follow-up of medical management of miscarriage

Objective: To evaluate the percentage change in total beta eta-unit human chorionic gonadotropin (beta hCG) levels (%Delta beta hCG) in the prediction of treatment outcomes following intravaginal misoprostol for missed miscarriage before 13 weeks. Methods: A secondary analysis of a randomised controlled study of medical management of miscarriage was performed. Total beta hCG levels were collected before misoprostol (baseline) and after a planned seven day interval (follow-up), when a transvaginal ultrasound (TVUS) reported a gestational sac as present or not. If no sac at TVUS, surgery was indicated on clinical criteria. %Delta beta hCG ((baseline beta hCG - follow-up beta hCG)/baseline beta hCG x 100) was evaluated in the prediction of a sac at TVUS and surgery on clinical criteria. Results: %Delta beta hCG was calculated for cases with beta hCG levels within two days of misoprostol and TVUS; calculation interval determined case number. The median %Delta beta hCG for 24 cases with a persistent sac (6-9 day interval) was significantly lower than for 145 with no sac (58.75% (interquartile range (IQR): 37.59-76.69; maximum 86.54) vs 97.65% (IQR: 95.44-98.43); P < 0.0001). The median %Delta beta hCG for eight cases needing surgery on clinical criteria (5-9 day interval) was significantly lower than for 140 cases with no sac not needing surgery (79.68% (IQR: 64.63-91.15; maximum 94.06) vs 97.68% (IQR: 95.61-98.50); P < 0.0001). The area under the receiver-operator curve was 0.975 for prediction of a persistent sac and 0.944 for prediction of surgery on clinical criteria, respectively. %Delta beta hCG > 87% predicted no sac at TVUS. %Delta beta hCG > 94.5% predicted no surgery on clinical criteria. Conclusion: %Delta beta hCG calculation over one week reliably predicted treatment outcomes after medical management of missed miscarriage.