The Use of Beta-Human Chorionic Gonadotropin (β-hCG) Levels as a Predictor of Successful Medical Management of Ectopic Pregnancy

Objectives The early diagnosis of ectopic pregnancy is essential in determining the appropriate therapeutic approach. This study demonstrates the important factors considered in the prediction of a successful medical treatment, which will, in turn, improve the quality of patient counseling and guidance prior to the initiation of the treatment. Methods This was a retrospective cohort study of 58 ectopic pregnancies that were treated medically with methotrexate in Bahrain Defense Force (BDF) Hospital from January 2016 to January 2021. All patients that were offered medical treatment of ectopic pregnancy and completed the follow-up were included in the study. StatsDirect software was used to analyze the baseline characteristics of the successful and failed medical treatment of ectopic groups. Simple linear regression was used to correlate initial beta-human chorionic gonadotropin (β-hCG) levels and the drop of β-hCG levels after one week of medical treatment. Results Patients were divided into two outcomes: the primary outcome represented in the successful treatment group, 68.9% (40/58), and the secondary outcome represented in the unsuccessful treatment group 31% (18/58). The mean β-hCG level in the successful group was significantly lower than that of the unsuccessful treatment group (1403.6±1421 IU/L versus 2845.1±1705 IU/L, p=0.001). There were no differences between the two groups with regards to the size of the adnexal mass, presence of gestational sac, or size of the gestational sac. The cut-off value of the initial β-hCG level for successful medical treatment was 2,141 IU/L, with 72% sensitivity, 75% specificity, and receiver operator curve (ROC) of 0.76 [95% confidence interval (CI) = 0.63 to 0.89)]. The cut-off value of β-hCG fell between day four and day seven and was 37.2%, with 78% sensitivity, 68% specificity, and a ROC curve of 0.72 (95% CI = 0.55 to 0.89). Conclusion This study found that low initial β-hCG levels can be used to predict successful methotrexate treatment of ectopic pregnancy. In this cohort of patients, the cut-off level of initial β-hCG for successful treatment was 2141 IU/L.