The fall in serum hCG over 48 hours may be measured as the hCG ratio, which is calculated as:
  
    
      
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              48
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              0
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    {\displaystyle hCG~ratio={\frac {hCG~at~48h}{hCG~at~0h}}}
  
An hCG ratio of 0.87, that is, a decrease in hCG of 13% over 48 hours, has a sensitivity of 93% and specificity of 97% for predicting a failing pregnancy of unknown location (PUL).
Doxercalciferol (or 1-hydroxyergocalciferol,  trade name Hectorol) is drug for secondary hyperparathyroidism and metabolic bone disease. It is a synthetic analog of ergocalciferol (vitamin D2). It suppresses parathyroid synthesis and secretion.Docercalciferol is the vitamin D2 analogue of alfacalcidol. It undergoes 25-hydroxylation in the liver to become the active ercalcitriol, without the involvement of kidneys. == References ==