3rd Trimester Health Resources

The final 29-40 weeks of pregnancy are referred to as the third trimester. In this time, even more changes will be taking place as you and your baby prepare for birth. There are quite a few things to think about during this exciting time:

Flying during pregnancy

Flying during pregnancy is completely safe. If you are taking a long trip, however, you may want to think about keeping more room around you for comfort and being able to walk around.

During a long flight, it is also important to remember to keep your fluid levels high by drinking a lot of water and doing leg and ankle exercises to maintain healthy blood flow.

In the third trimester, some airlines will place restrictions on airline travel. You may be required to present a note from a doctor or midwife stating you are all right to fly. International flights may restrict traveler’s insurance based on their own company policies.

Check with your doctor or fertility specialist and the airline before planning a trip. Check out this travel resource for great tips on traveling with infants and young children. For more general information, read this travel survival guide by the CDC.


Premature babies and breathing

baby incubator
Source: Public Health Agency

Babies that are born prematurely, often need assistance with taking their first breaths. They can also be at risk for respiratory distress syndrome (RDS).

RDS is a breathing disorder that affects newborns resulting from not enough surfactant (the fluid which coats the inner surface of the baby’s air sacs and stops them from collapsing when the baby breathes) being produced.

If a newborn baby is having trouble breathing, they may be given help with a ventilator in addition to extra surfactant to compensate for the fact that their lungs can’t yet produce it normally.

High blood pressure

During your pregnancy, you may experience increased bloodpressure (referred to as pregnancy-induced hypertension, or PIH). This can become serious if PIH leads to pre-eclampsia, a disorder that causes protien in your urine and swelling.

Pre-eclampsia can affect other parts of your body including the liver, brains, lungs or blood clotting system, which is why it’s important to discuss any increase in blood pressure with your doctor of fertility specialist.

Between five and 15 percent of women develop PIH, and it is more common with your first baby. It can be treated with drugs, and, as with a lot of medical issues that can arise during your pregnancy, lots of rest and relaxation.

Baby’s head not engaging

While, statistically, it is very likely that you and your baby will fit together, in a few cases your baby’s head not engaging your pelvis could be a sign of cephalopelvic disproportion, the medical term for a baby that is just a little too big for mommy.  It can also mean simply that your baby is waiting until labor begins to engage.

It is possible to have a baby that is just a little bit too big for you, although most of the time you will be matched with a baby that is your size. Smaller women tend to produce smaller babies.

This will usually be treated during labor with a caesarean birth.

Disproportion in one pregnancy does not at all mean that subsequent pregnancies will also be disproportionate.



The area of skin between your vagina and anus will experience a lot of stretching during the birth of your baby. Occasionally, your doctor or midwife may want to perform an episiotomy, or a small cut in the perineum repaired by stitches after the birth.

Small tears in the perineum are common and quickly heal themselves. A larger tear that occurs during birth may require stitches.

The head engages

This part is sometimes compared to an egg fitting into an egg cup. This is when your baby’s head has dropped down and is firmly fixed into your pelvis and ready for labor.

You may experience it from the top as a lightening feeling where your baby no longer presses against your diaphragm. This may also make breathing easier.

On the other end of things (literally) you may feel slightly uncomfortable as the baby’s head fills a previously unoccupied spot in preparation for labor.

Whichever way you feel it (perhaps both), engagement is a great sign that your baby is in a good position to enter the world.


You’ve made it. Although you have had to make some pretty radical lifestyle changes to accommodate your pregnancy, setting up your world for your new baby will be a task all in itself. The end of the third trimester marks the end of your pregnancy and in finishing the process, you have participated in the beautiful wonder that is the creation of life. Well done, you!

Images from CDC.gov, nlm.nih.gov