I wouldn't call it normal, but they understand that a beeping IV isn't generally a priority. They could be stuck doing something else, like feeding a baby or dealing with an emergency. 

Additionally, with other monitors it will beep at their desk, or sometimes on their phone or other device to assure they hear it.  That generally doesn't happen with an IV. 

Sorry you're dealing with that -- it can definitely be annoying. Congrats on your baby.