wow, this is kind of a classic boards questions.
here's my answer: It depends.
If the hospital is staffing the OB and surgical services with the expectation that you cover both.
It's not only unethical, it's illegal.
If the hospital IS NOT set up as a trauma, or high risk/emergency OB service (in other words, expecting this to happen as part of their regular function), and your stated responsibility is to "try" and cover a C/S just in a catastrophe situation. That's slightly different.
The important point to make is that under this situation, your responsibility still lies, 100% with your primary patient. Your ability to provide ANY care to the C/S is only at your discretion, and it should be a very stringent discretion, in a very unique situation, and again, ONLY in a catastrophe situation.
That same situation also justifies you telling them that you're busy and they have to proceed under local.
If they're uncomfortable or unable to conduct a C/S under local, then you SHOULD NOT agree to potentially accept responsibility for leaving your patient to take care of theirs, as they have no other backup if you are tied up.
On the mother/baby topic:
A friend of mine is a board examiner and failed an examinee for answering that he would not, under any circumstances, leave the mother to help deal with the baby (this was after offering up a dozen different versions of the situation).
The basic principle is that you're primary responsibilty is to your patient.
If the baby is in distress, and the mother is chilling, walk over and take a look.
If the mother isn't doing so well and requires a bit more of your attention, to the point where walking across the OR to look at the baby is too difficult. . . have them wheel the baby over to you.
If your hands are so full that, with a newborn in the warmer, right next to you, within arms reach, and you still can't try and intubate/assist. Then it should be pretty bloody obvious that they shouldn't be asking you to help anyway.
Just to clarify, so I don't get people enraged about the guy who failed.
The situation was finally boiled down to the examinee like this:
your patient, the mother, is under spinal anesthesia and is rock stable. Her vitals are fine, she's satting 100% on room air, she's begging you to go save her baby, the father is sitting next to her and is doing the same. The nurse has wheeled the baby over to you and is holding a laryngoscope in her hands. Would you still not evaluate the baby or try to assist?
His response was a consistent and robotic: "my primary responsibility is to my patient, under no circumstances will I leave her care."
The mother baby debate though is a LOT different than being asked to leave a room with someone under general to potentially, completely, tie yourself up with a critical patient.
We cover codes in our hospital as part of our responsibilities, but if we're already busy with something else (often an emergency C/S), we call them back and tell them their on their own.
If your hospital is expecting crash C/S's, then they need to better prepare for them, if their contingency plan for a rare, catastrophic kind of situation involves stretching you, that's acceptable, as long as they are comfortable with the fact that you may very well need to refuse and be unavailable, in which case they need to have another back up plan.
I'm post-call right now so I might be rambling a bit.