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Third trimester guide: Baby, here we come!

Baby’s almost here! You’re definitely excited to meet your bundle of joy, but you might be a little short on energy. Make sure you know what to expect in the final push so that you can welcome Baby in a happy and healthy state.


Unfortunately, the third trimester can be the most painful and uncomfortable phase of your pregnancy. As Baby grows and you continue to gain weight, you’ll feel some strain here and there. Here are some symptoms that might be coming your way:

  • Fatigue: Most women gain 20-30 pounds (9-13.6 kg) by the end of their third trimester, so you’re bound to get tired if you feel like you’re lugging around a watermelon in your womb. Try combatting the exhaustion with light exercise and small meals throughout the day, and never hesitate to get some well-deserved rest.
  • Back pain: A growing baby, along with hormones to loosen your joints in preparation for childbirth, puts stress on your pelvis and lower back. There are lots of stretches or exercises you can do to improve your posture, or you can try supportive garments to lift your stomach.
  • Heartburn: When your uterus grows, it can shift around your organs a bit, and a change in stomach position can lead to heartburn. You can control this by monitoring what and how much you eat in one sitting, so you might want to stay away from fried or spicy foods and try to eat small meals throughout the day.
  • Swelling: As Baby takes up more real estate in your body, the uterus presses against vessels that take blood to and from the heart, which can cause swelling in your limbs or extremities. Try going for a swim or just lying down on your side to improve circulation.
  • Breast growth and discharge: Most women put on about 2 pounds (900 g) of extra breast tissue by the third trimester, so your breasts could become tender. They might also start secreting a yellow liquid called colostrum, which is important for delivering nutrients to Baby in the first few days after delivery.

Health care provider appointments

Third trimester healthcare provider visits will occur more often than those in the first six months, and you’ll probably have appointments every two weeks until week 36 when they become weekly until labor. You’ll talk about delivery in detail and continue to receive standard physical exams to check for potential problems.

At some point during the third trimester, your healthcare provider will probably suggest getting a Tdap vaccine. The Tdap is given during pregnancy to help protect the baby, who is protected through maternal antibodies passed on before birth, from whooping cough. The vaccine lasts until around 2 months old, and is important because babies are at the highest risk for whooping cough, and, with their as-yet-unformed immune systems, have the least ability to fight it off.

As always, these appointments give you time to talk about worrisome symptoms and discuss results from previous tests. Baby’s size and heartbeat will continue to be monitored, in addition to their position. An ultrasound is the best way to determine if they are oriented bottom-down and, if this is the case, you can schedule a procedure to internally or externally turn them.

You probably won’t be having regular pelvic exams unless your healthcare provider suspects an issue, but if you’re more than a few days past your due date it is important to check the condition or dilation of the cervix.

Take advantage of these appointments to talk about your concerns regarding childbirth or postpartum issues, such as breastfeeding or contraception after Baby is born. The best preparation for going into labor is expanding your knowledge and having clear expectations for what you will experience.


Your healthcare provider can perform more tests in the third trimester since Baby is more developed. These will include vaginal exams to check their position and evaluate the condition of your cervix.

  • Group B strep test: Group B strep bacteria lives in about 1 in 3 women, and is not dangerous for moms-to-be, but could affect Baby when they pass through the birth canal, where the bacteria resides. The test is performed with a simple vaginal and rectal swab, and if you get a positive result, it can be treated with antibiotics so that they doesn’t have it at birth.
  • Non-stress test: This is usually reserved for high-risk pregnancies or women past their due date. It monitors Baby’s heart rate with a strap across your abdomen to make sure they are developing well.
  • Biophysical profile (BPP): A BPP is a combination of tests to evaluate Baby’s heart rate, muscle tone, and movement. It also assesses the amount of amniotic fluid around them, which is a factor that can contribute unsafe conditions. This is also performed mainly for high-risk pregnancies or for women susceptible to certain diseases.
  • Oxytocin challenge test: Frequent or intense contractions limit the amount of oxygen Baby receives during labor, so your healthcare provider might perform this test to see how they respond to simulated contractions. This is usually done only when your healthcare provider anticipates that the baby will struggle under stress.

All in all, these tests give you a good idea of any foreseeable issues in labor. Seeing that your baby is in a good position with a steady heartbeat should put you at ease for a safe and healthy delivery.

Read more
  • Mayo Clinic Staff. “Biophysical Profile.” Mayo Clinic. Mayo Clinic, 3/5/2015. Web.
  • Mayo Clinic Staff. “Third trimester pregnancy: What to expect.” Mayo Clinic. Mayo Clinic, 5/5/2014. Web.
  • “Body changes and discomforts.” U.S. Department of Health & Human Services, 9/27/2010. Web.

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