Ectopic pregnancy: using the hCG ratio to select women for expectant or medical management.

OBJECTIVE

To identify variables that can be used to select women with an ectopic pregnancy for expectant or medical management with systemic methotrexate.

DESIGN

Cohort study.

SETTING

Early Pregnancy Unit of a London teaching hospital.

POPULATION

Women with a tubal ectopic pregnancy managed non-surgically.

METHODS

The diagnosis of tubal ectopic pregnancy was made using transvaginal sonography. Human chorionic gonadotrophin (hCG) levels had to be taken at 0 hour and 48 hours pre-treatment. Other recorded variables include presenting complaints, gestational age, progesterone levels, size of the ectopic mass and appearance of the ectopic on transvaginal sonography. Women were followed up until the outcome (success or failure) of management was known.

MAIN OUTCOME MEASURES

Univariable analysis was performed to identify the variables associated with successful management using area under curves and relative risks.

RESULTS

Thirty-nine women underwent expectant management (overall success rate 71.8%) and 42 had medical management (overall success rate 76.2%). The pre-treatment hCG ratio (hCG 48 hours/hCG 0 hour) was related to the failure of both expectant (area under curve 0.86, 95% CI 0.67-0.94) and medical (area under curve 0.79, 95% CI 0.58-0.90) management. History of ectopic pregnancy was related to failure of expectant management only (relative risk 0.46, 95% CI 0.16-0.92).

CONCLUSIONS

The most important variable for predicting the likelihood of successful non-surgical management was the pre-treatment hCG ratio. New studies are required to validate the use of this variable and of history of ectopic pregnancy to predict the likelihood of successful non-surgical management in clinical practice.