Hospital Scenario: Medical Ethics & Plot Twists for Screenwriters

Question
Dr. Rappaport -

This requires a bit of explanation, so please bear with me before I get to my question.

I am a writer in Los Angeles who's working on a detective story.  My story involves a woman who arrives at a hospital with a newborn baby.  She tells the hospital staff the baby is hers and that she'd like medical care for it.

The twist (which we don't find out until later) is that the baby is actually someone else's.  In fact, what I need for the hospital to realize is that the woman couldn't possibly have given birth to a baby anytime recently because she shows no signs of having done so.  So the mystery is, who's the baby's real mother, and where is she?

My questions are: 1. What kinds of tests would the hospital run to determine that this woman and baby are not related?  2. What physical clues might make a doctor or nurse suspicious about the situation and run those tests?  3. And what would the hospital staff tell the police, whom I'm assuming they'd call if they feared something happened to the baby's real mother?

Thanks in advance for your time.  I'm looking to make this as accurate as possible, so please feel free to provide as much detail as you like.

Regards,

Eric Haywood

Answer
If the woman claimed to have recently delivered the baby (less than 6 weeks) she would still be bleeding vaginally and her uterus would still be enlarged. (It is quite easy to identify a recent  parturant.)  The baby and the woman woujld have their blood taken for type and Rh, although this would not  prove whether the woman is the mother. However, if the police become involved, a DNA test of the baby and the mother will show if she is the mother.  A pelvic exam of the woman would show if her cervix was still sometwhat dilated and if she recently had any tears or cuts in her vagina or on her perineum.  Certaily, the woman may also be lactating if the baby was less than a week old (or more if she was breastfeeding).  The only thing that the staff could tell the police is that they are suspicious about a patient. There are laws concerning confidentiality of data and even the police have no jurisdiction to them unless a crime is first shown to have existed. Remember, also, that there are now "Safe Haven" laws in most states allowing a woman to drop off a newborn at any hospital or police station with no questions asked and the woman would be allowed to leave the hospital without interception. However, if a kednapping is suspected, the police may be notified and they may start an investigation.