* An extra set or two of clothes for baby, and an extra shirt or sweater for you. This is obviously for that blow out diaper that will occur at the worst possible time, as well as spit-up.
* Diapers, wipes, diaper rash ointment. Pack more diapers and wipes than you think you will need—anticipate delays. Babycenter recommends one diaper for each hour you will be in transit.
*Disposable changing pads – Huggies makes a disposable changing pad that can be used once and thrown away. If you don’t care for these, like me, make sure your changing pad is removable and not attached to your diaper bag. Airplane restrooms are tiny, so you will need to take the pad out and make it fit the space.
*Plastic bags to dispose of the mess. It could be helpful to pack each diaper in its own plastic bag so you are certain you don’t run out.
* Whatever your baby eats. TSA regulations permit baby formula, breast milk, and baby food in carry-on luggage, so long as you are traveling with your child. You will not be asked to test or taste these, but you may be asked to open the containers. You have to declare these items once you get to security. Don't forget small plastic dished, spoons, and disposable or vinyl bibs if your baby easts solids.
* Small bottles of hand sanitizer, baby wash, and baby lotion
* Favorite toys, blankets, teddy bear, or pacifier or other soothing tool. Bring extra pacifiers in case they get dropped and lost, plus pacifier wipes to sanitize any dropped pacis.
* A new toy to distract the child.
* If your baby is teething, bring some teething rings and biscuits for them to chew on. Gel filled teethers are allowed in your carry-on.
* Medications needed for you and/or your child, prescriptions, and your pediatrician's phone number.
* Bottled water and a snack for you. Snacks shouldn't be an issue, but water will have to be purchased once you are through security. Most domestic flights no longer have meal service (except in First Class), so be prepared.
* Sling or front carrier to help you get safely through crowded areas (i.e. airport). You might even consider this in lieu of a stroller.
* Birth certificate or vaccination records as baby's proof of identity.
* Baby Clothes—you can organize your baby’s clothes using resealable plastic bags, so you don’t have to rummage through the entire suitcase to find a matching sock. Pack an outfit or two for each day (including sleepwear) in a gallon-size bag. Use the clean empty bags for soiled clothes later on.
* Extra diapers & wipes—you might assume that you can find these items at your destination, but that is not always the case. If it is not an area you are familiar with, you may have trouble locating the brand you normally use. If you are using cloth diapers, be sure to pack detergent so that you can soak them as soon as you arrive and do laundry when needed.
* If you are visiting family, you can ask them to help you find the nearest store that carries your brands of diapers, formula, etc. You can also order large items, such as formula, to be shipped to your destination, if you are planning a longer trip.
* Clothes for You: Take a few extra tops for spit-up, spills, and other disasters mentioned above.
* Portable crib or playpen for your child to sleep in. This will incur an extra fee, so if you are traveling to visit family or friends, see if someone has one you can borrow. You might also consider buying a used one once you get to your destination form somewhere like Once Upon a Child. This could actually be cheaper than paying a checked luggage fee each way.
* Inflatable bathtub to make bath time easier at your destination.
* Car seat and stroller. If you are checking your car seat, I recommend buying a travel bag for it to protect it from rough handling. Most airlines allow you to check your car seat at no additional cost. The same thing goes for your stroller
* Extra medication, sunscreen, diaper rash lotion, and other toiletries. You may not be able to find your favorite brand at your destination, so pack a few extras, just in case. Put these in clear plastic bags in your luggage so they can be seen by safety inspectors when they open your bag. Plastic bags also protect against spillage.
Can you guys think of anything I have missed?