I think it’s okay to fly with your newborn baby straight away. After 1 week of age the Federal Aviation Association (FAA) says it’s okay, as does the AAP, but always recommends a separate seat for your infant whenever possible.
The biggest risk flying with a healthy newborn is exposure to infection. So, like any decision in life, you have to weigh the risks and benefits of a decision. Because we take fever very seriously in babies under 3 months of age, we want to avoid infections when possible. Take precautions, wash your hands frequently, and wipe down seat backs, tray tables, and seatbelts on board.
All that being said, I flew with O when he was just 6 weeks old. It was important for us to travel to see family in California for the holidays. I took precautions, loaded up on hand sanitizer, and packed extra diapers. It was a wonderful Christmas…
For more on traveling with children, check out:
Is Air Travel Safe For an Infant (the short answer is “yes”)