Progesterone concentration as a predictor of pregnancy normalcy is the most useful when hCG levels are less than 2000 mIU/mL

Abstract
Measurements of serum progesterone to predict early gestational normalcy have been found to be as predictive as serial hCG titers. Since ultrasound would be the diagnostic tool of choice if hCG was >2000 mIU/ml, the purpose of the present study was to determine the best predictive value of a single progesterone measurement when hCG levels were 0.005). A single serum progesterone level has a better predictive value of pregnancy normalcy when hCG measurements are <2000 mIU/ml.