A last minute 'babymoon' or flights home to see family before the imminent arrival ... there are many reasons to travel while pregnant, but knowing the guidelines will help you better plan your trip. If you're pregnant and planning on jetting off, here are the things you need to know.

Baby onboard - plan before you fly.

First and foremost, you should discuss your intended travel plans with your doctor well before you book your flight.  In most circumstances they'll need to give you medical clearance and provide you with a medical certificate to keep handy, so they should always be your first checkpoint.

For the most part, if you're healthy and undergoing a routine pregnancy (that is, a pregnancy with no medical concerns or complications), you're good to go and travel up until 28 weeks. It's from the 28-week mark that the airlines start to enforce certain rules, so it's always best to plan your travel – if possible – within your first or second trimester.

Make sure you have all the necessary documentation.

Importantly, you'll need to carry a medical certificate on you from 28 weeks. This is a letter from your registered medical practitioner or registered midwife providing key information, such as your estimated due date; whether this is a single or multiple pregnancy (i.e. twins); whether this is a routine pregnancy, and stating that there are no complications with the pregnancy. You'll need to keep this handy so it's available on request during check-in at the airport and during the flight.  Medical clearance is required if you are having complications with your pregnancy (that is, if the pregnancy is not considered routine).

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Between 28 to 40 weeks for a single pregnancy, airlines such as Qantas and Jetstar will allow you to travel on flights under four hours. For multiple pregnancies, you are allowed to travel until the end of your 36th week. Virgin's policy stipulates you have the OK to fly with a medical certificate up until 38 weeks for flights under four hours.

For flights over four hours, Qantas, Jetstar and Virgin allow travel up until the end of the 36th week for single pregnancies and the end of the 32nd week for multiple pregnancies.

Ask for an aisle seat so you can move around easily.

Not all airlines are the same, though, so it's important to speak with your travel agent before you book. Air New Zealand, for example, will allow you to travel up until the end of the 35th week for flights over five hours and to the end of the 37th week for flights under five hours. For multiple pregnancies, you can travel up to the end of the 31st week.

Anyone who has experienced a pregnancy will know those aches and pains hang around at the best of times so how do you make it work on a flight? While onboard, be sure to drink lots of water and walk around often to keep your circulation flowing. It is also recommended to take out travel insurance that covers you for serious pregnancy-related medical complications.  You may have to pay extra for this cover.  Most travel insurance policies won’t cover you and your baby for premature birth.   If you don’t have a policy that covers these things you should re-cconsider travelling overseas after the 23rd week of pregnancy 

For medical reasons, it's unlikely you'll score an exit row seat but you can request an aisle seat, which will make getting up to walk around much easier, and more comfortable for you.

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