HCG (preganncy) testing
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þ Mercy tests:
 - As of 11/17/98, Mercy does enzyme immunoassay based on "sandwich" principle
  + tests for _both_ alpha and beta units, measuring whole molecule so _not_
   "beta" HCG
  + studies of 104 nonpregnant women and 95 men gave levels less than 6;
    replicated with smaller numbers at Mercy
  + mimimum detectable is 1.0 mIU.ml
  + expected levels:
    Gest. Age           Expected HCG (mIU/ml)
    0.2-1 week          5-50
    1-2 weeks           50-500
    2-3 weeks           100-5,000
    3-4 weeks           500-10,000
    4-5 weeks           1,000-50,000
    5-6 weeks           10,000-100,000
    6-8 weeks           15,000-200,000
    2-3 months          10,000-100,000
þ "Doubling"
 - per Magee, ^ 66% in 2 days.
 - their protocol is to use the "HCG board" to check for "doubling"
   but they do this _twice_, once in 2 days and once in 4 days.
 - if not doubling, they offer "diagnostic D+C" (not abortion as not viable
   pregnancy) or possibly laparoscopy and methotrexate; maybe methotrexate
   alone but stringent requirements
 - Methotrexate order NOT written by emergency physicians, but by OB resident
   after consult with attending OB.