Third Trimester of Pregnancy: Doctor's Appointments and Tests

If you’re in your third trimester (weeks 28 through 40 weeks) you’re in the home stretch. Doctor visits are coming up more frequently, and depending on how your pregnancy is progressing so far, you will either have them monthly or weekly. Near the last few weeks of the third trimester, weekly visits are not uncommon.

The new approach to prenatal care since the advent of the COVID-19 epidemic (not only to prenatal care but all medical visits) means that in-person contacts are limited by reducing in-person visits at your doctor’s office and the hospital and replacing some in-person care with virtual prenatal care. 

Doctor’s appointments

Like with the second trimester, third-trimester doctor’s appointments begin with a physical examination, pelvic exam, and sometimes an ultrasound. Your blood pressure and weight will be checked and the doctor would take note of fetal movements and check the heartbeat. Your doctor will also check your level of swelling. During this time, you may also be asked to track the movement of your baby.

During these appointments, your doctor will ask you questions about your health and your pregnancy. Questions you may be asked include: “Have you been having headaches” and “Have you been feeling contractions.”

Near the end of the third trimester, many of your appointments are based around checking the baby’s position. If your baby is feet first (breech) or rump first, they will attempt to turn your baby by pressing gently on your abdomen.

In addition, your doctor will also measure your cervix to look for how much you are dilated and how thin it is. This is to look for signs that you will be delivering your baby soon, with your cervix opening and thinning out more as you near the end of your third trimester.

Tests and screenings

Aside from checking your cervix and measuring your baby, additional tests are performed during your last trimester. These are routine tests that offer your OB-GYN additional information about your health and the health of your baby.

  • Group B Strep: One of the screenings performed in the third trimester is group B streptococcus, or group B strep (GBS). The American College of Obstetricians and Gynecologists now recommends performing universal GBS screening during a 2-week window between 36 0/7 and 37 6/7 weeks of gestation. This test looks for a type of bacteria that is harmless to you but can make your baby ill.
  • Blood and lab tests: If you were previously diagnosed with anemia, your doctor will run another blood test to check your iron levels. The same goes if you are at risk for a sexually transmitted infection, such as gonorrhea, HIV, or Chlamydia. Your blood glucose level is checked again if it was high during a previous test. Your protein in the urine levels will be checked for any indications of preeclampsia.
  • Ultrasound: If you had a low lying placenta or were found to have placenta previa during a second-trimester ultrasound, another ultrasound is performed to look for your placenta’s current location.
  • Non-stress test: The non-stress test is done in the last weeks of your pregnancy to take a closer look at your baby’s heartbeat, especially if you are still pregnant past 40 weeks.

Third-trimester doctor visits and tests are primarily focused around you being ready for labor and delivery. Your third-trimester doctor visits are also a good time to ask any lingering questions you may have about the impending labor and delivery and postpartum considerations.

Read More: 
Third Trimester Checklist
Pregnancy Week by Week
The Six Trimesters of Pregnancy