I hope they find the reason very soon, and wish her a very speedy recovery, being in ER is not a fun time at all and so very scary with sucha wee little bubba, keeping them in my thoughts and prayers
Take something in for mum, especially some yummy food, hospital food isn't so great and she won't want to leave bubs side for very long.
Take care xxoo
Hope things go well for your sister and your niece.
In a baby this young, fevers are almost always the result of a viral infection, and are self resolving. But because on rare occasions they can be bacterial infections, and much more serious, there is a standard set of tests that we do to make sure we aren't missing something. These include a chest x-ray (to check for pneumonia), a urine test (to check for urinary tract infection) and a lumbar puncture (to test for meningitis).
And yes, taking blood from a three week old can be very challenging.
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