The baby's stroller goes through the airport with you. You will need to fold it to send it through the security x-ray scanner if at all possible (otherwise, it will need to be hand-inspected). When you get to your gate, ask the agent for a gate check tag for the stroller (put the tag on the stroller). When you go to board the plane, you will fold and leave your stroller just outside the door of the plane (after you walk down the big ramp headed for the plane). The crew will put the stroller underneath the plane. When you arrive at your destination, you will find your stroller waiting for you just outside the door of the airplane again. Some people choose to have a bag to put the stroller in because it can get dirty underneath the plane. I'd rather have a greasy/stained $14 bag than a greasy/stained stroller. The stroller will not count towards your luggage allotment. A car seat can also be checked or gate checked.
Here are some tips for traveling with a baby:
- Remove all loose/removable parts from the stroller before checking it to make sure they don't get lost.
- Bring chewy snacks and a drink for take off and landing to try to help reduce the pressure in the baby's ears
- Leave early so you have lots of time to get through security
- Bring twice as much baby stuff (diapers, formula, etc) as you think you will need with you in your carry on luggage. If you are delayed once your luggage is checked, you won't be able to get to anything in your checked bags.
- Consider buying a seat for your infant. Then they can be in their familiar car seat (as long as it is FAA approved, which most are). It is safer for them.
- Check the TSA website for guidelines about what can, and can't, be brought through security.
Good luck!