Image credit: Sean McGrath

On Tuesday night, a woman gave birth on a Southwest flight from San Francisco to Phoenix.

Mother and baby are fine (luckily, a doctor and a nurse were flying Southwest that day), but the plane did have to make an emergency landing in Los Angeles, which led to a two-hour delay for those headed to Phoenix.

It’s unknown how far along the mother was or if the baby simply arrived prematurely.

This leads us to the question: can you fly while in your third trimester? There are some common misconceptions out there about flying while pregnant, but the reality is, there is no one set of rules.

In theory, the best time to fly is in your second trimester, around weeks 14 to 28—assuming it’s not a high-risk pregnancy.

In reality, many women choose to fly in their third trimester.

Always carry a set of your prenatal records, and be aware that you may need a signed medical certificate from your doctor.

American Airlines requires a certificate within four weeks of your due date.

United requires a certificate—in triplicate! It has to be issued within 72 hours of your flight departure, but they actually recommend that it be dated within one day.

Delta, Alaska, and Southwest don’t have any restrictions.

But remember, if you have to cancel or change your flight, you’re still responsible for extra fees.

If you have travel insurance—especially a policy that includes health coverage—check the fine print carefully. Many policies have cutoff dates around week 28, so you may not be covered if something goes wrong in transit.

For more information, visit the Family/Kids Travel archives.

Keep reading for more travel tips.