What serial hCG can tell you, and cannot tell you, about an early pregnancy

The serial measurement of serum hCG concentrations is an important clinical tool used to differentiate normal from abnormal pregnancies. At hCG values below which ultrasonography can be diagnostic, the comparison of a patient's hCG dynamics to those of established expected curves of rise or fall can aid the clinician in determining when to follow expectantly and when to intervene. Still, this method has some limitations and should never supersede clinical judgment based on symptoms or signs.