How and when human chorionic gonadotropin curves in women with an ectopic pregnancy mimic other outcomes: differences by race and ethnicity.

Objective: To investigate the hCG profiles in a diverse patient group with ectopic pregnancy (EP) and to understand when they may mimic the curves of an intrauterine pregnancy (IUP) or spontaneous abortion (SAB).

Design: Retrospective cohort study.

Setting: Three university hospitals.

Patient(s): One hundred seventy-nine women with symptomatic pregnancy of unknown location.

Intervention(s): None.

Main Outcome Measure(s): Slope of log hCG; days and visits to final diagnosis.

Result(s): Of women with an EP, 60% initially exhibited an increase in hCG values, with a median slope of 32% increase in 2 days; 40% of subjects initially had an hCG decrease, with the median slope calculated as a 15% decline in 2 days. In total, the hCG curves in 27% of women diagnosed with EP resembled that of a growing IUP or SAB. Of the EP hCG curves, 16% demonstrated a change in the direction of the slope of the curve. This was more common in African Americans and less evident in Hispanics. Furthermore, it was associated with more clinical visits and days until final diagnosis.

Conclusion(s): The rate of change in serial hCG values can be used to distinguish EP from an IUP or SAB in only 73% of cases. The number of women who had a change in direction of serial hCG values was associated with race and ethnicity.