Prenatal Tests During The Third Trimester of Pregnancy

Congratulations! It's almost time to meet the love of your life. To make sure your baby is healthy and strong, you need to receive third trimester prenatal tests.
Prenatal Tests During The Third Trimester of Pregnancy

Last update: 25 June, 2019

You’ve reached the last stage of the most beautiful thing women get to experience. During your pregnancy, you need to make sure to get checked out, including receiving third trimester prenatal tests. In this article, we’ll tell you what tests you’ll receive.

Depending on the type of pregnancy, you’ll probably need to receive one test every two weeks and then one test a week. Take note of the recommended tests during this stage and enjoy the changes your body experiences.

The importance of prenatal tests during the third trimester of pregnancy

Each trimester involves a series of tests that allow pregnancies to reach successful conclusions. Each test is very important because it allows doctors to know how healthy both mother and baby are.

Prenatal tests during the third trimester of pregnancy are important because they help detect infections that can be transmitted through the birth canal. In addition, they monitor the fetus’ cardiac activity and vital functions.

It’s worth mentioning that every pregnant woman is unique and so is her baby. Therefore, the medical conditions of the tests may vary. It’s a decision the treating physician and the parents make together. Nonetheless, you must be aware of the tests that exist and, of course, of their importance.

Third trimester of pregnancy prenatal testing

During this stage of pregnancy, your doctor will ask you how you feel and explain what contractions and fluid retention are and the ailments you may suffer from. If they don’t do it, we recommend that you ask them to clear up any doubts you may have.

Prenatal Tests During the Third Trimester of Pregnancy

Based on the physical examination, we’re sure your doctor will recommend the following prenatal tests during the third trimester of pregnancy:

Streptococcus screening

By week 35, your doctor will most likely ask for a group B streptococcus test to determine if you have this infection. Usually, these bacteria live in the vagina and are transmitted to the baby during birth, which can be severe.

A sample is taken from the vagina for this test. If the result is positive, antibiotics are administered intravenously.

Glucose screening

Glucose screening is also required during this trimester. This test helps rule out possible gestational diabetes, a temporary condition that can affect the baby’s health. It’s best if it’s diagnosed and treated in time.


It’s considered one of the most important prenatal tests during the third trimester of pregnancy. With this test, you can determine and compare fetal growth and anatomy.

It’s essential to monitor the development of organs such as the lungs and kidneys, among other structures. If any anomalies are detected, the doctor will decide what steps to take.

“Prenatal tests during the third trimester of pregnancy are important because they help detect infections that can be transmitted through the birth canal.”

Physical test

The doctor may also perform a physical test to verify the health of the mother and the fetus’ response to stimulation. During this test, doctors often perform the nonstress test.

This test indicates when fetal movement decreases or if there’s a reason to believe that the placenta isn’t working properly. Depending on the result, further tests may be necessary.

Prenatal Tests During the Third Trimester of Pregnancy

Other tests

Depending on how the pregnancy has gone so far, the obstetrician may suggest repeating some tests, including urinalysis to rule out glucose and protein and red blood cell count to reduce the risk of anemia and rule out sexually transmitted diseases.

If the pregnancy continues for longer than 42 weeks, a biophysical profile will be performed to measure the heartbeat of the fetus and the amount of amniotic fluid.

This can be supplemented with an ultrasound to determine the status of the placenta. As for pelvic exams, each doctor decides which is the safest according to the patient.

In conclusion, third trimester prenatal tests let doctors know the best way of carrying pregnancies to term. Ideally, the patient’s blood pressure, weight, and rest periods should also be monitored, as they’ll determine the baby’s health.

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