What Tests are Done in Third Trimester Pregnancy?

What do you understand by the Third Trimester Test?

The Third trimester Tests are performed throughout your pregnancy to ensure the health of you and your baby. In the third trimester, several tests can be performed to make sure that everything is going well. You will have at least one ultrasound scan during this time, usually between weeks 30 and 34 of your pregnancy.

It is time to get ready for baby! Keep reading to learn why it is important to get a third-trimester test and know the risks. Learn about the various tests you can expect in your third trimester.

The third trimester of pregnancy is exciting. You are almost ready to meet your baby! But first, your doctor will make sure you and your baby are healthy by doing some tests. These tests may include:

• Group B streptococcus screening: Group B strep (GBS) is the leading cause of life-threatening infections in newborns and can also cause intellectual disability, impaired vision, and hearing loss. Up to 30% of all women have group B strep bacteria with no symptoms. When it is detected during pregnancy, you can get antibiotics during labour to reduce the chance that your baby will get sick from GBS. If you are pregnant or planning to become pregnant soon, be sure to get tested between 35 and 37 weeks for GBS so that you and your doctor are prepared for this potential risk factor.

The third-trimester tests will help identify if you have group B strep and if your baby has congenital hypothyroidism. If you are infected with group B strep, antibiotics will be given during labor and delivery to protect your baby from getting this infection. If a thyroid problem is detected in your baby, they can get treatment right away once they are born.

• Electronic fetal heart monitoring: Electronic fetal monitoring is done in the hospital and can be done any time after 20 weeks. Your doctor will use this test to monitor your baby’s heart rate. They will give you a belt with a monitor that is placed around your abdomen and attached to an external monitor.

• Urine and Blood tests: At the start of your third trimester, you will have another round of blood and urine tests. Your doctor will check your urine for protein and sugar and any signs of infection. He or she will also check your blood for signs of anaemia (low iron level) and any other problems that might suggest complications like pre-eclampsia. Some third-trimester tests are the same as those that are done during the second trimester. You will continue to check your blood pressure and urine, while your doctor keeps a close eye on signs of preeclampsia.

• Other required measurements: Continue regular visits to your doctor, you may have ultrasound tests, imaging scans, and several blood tests to evaluate your health and your baby’s development throughout this trimester. During the last few months of pregnancy, your baby is gaining weight rapidly. As a result, he or she may keep you up at night with lots of movements! Your doctor will continue to monitor your weight and watch for changes in your blood pressure that might indicate a need for bed rest or even early delivery.

• Non-stress test: A non-stress test involves strapping an external fetal monitor across the mother’s abdomen to measure the baby’s heart rate as it moves. In low-risk pregnancies, non-stress tests usually begin in the last few weeks of pregnancy and then weekly or twice a week until delivery.

The test takes about 20 to 40 minutes. To take it, your doctor will place two belts across your abdomen. One belt measures the pattern of the baby’s heart rate and the other detects the strength of your baby’s movements in response to stimuli (such as having cold water placed on your belly). This test is typically done twice weekly starting at 32 weeks.

• Contraction stress test: An unborn baby is connected to the mother by its umbilical cord, so it is important to predict how well it will cope with the stress of labour. Contractions may be stimulated with a drug called Pitocin. The strain of the contractions is monitored by a fetal monitor, and how your baby handles them is measured by a continuous recording of the baby’s heart rate. Doctors use these measurements to predict how well your baby will cope with the stress of labour.

• Ultrasound: An ultrasound is a test that uses sound waves to create a picture of your growing baby and surrounding areas. An ultrasound can help your care team monitor the health of your babies, and can also help them detect multiples earlier in pregnancy.

An ultrasound may be recommended more often than just once if you are pregnant with twins. Your doctor may choose to combine non-stress tests with an ultrasound to check the breathing motions, body movements, muscle tone, and amount of amniotic fluid.

• Biophysical profile: A biophysical profile, or BPP, is a test done during the third trimester of pregnancy to check how your baby is doing. It is used during the late second trimester or the third trimester to check how your placenta, amniotic fluid level, and baby’s movement are doing. This is usually done weekly when there are signs of fetal distress.

• STI (Sexually Transmitted Infection) Tests: Sexually transmitted infections can be passed to your baby during delivery. These include HIV, syphilis, gonorrhoea, and chlamydia. If these conditions are detected in time during pregnancy, they can be treated to prevent infecting your baby at birth.

• Amniocentesis: An amniocentesis is a test you may receive during pregnancy if your doctor thinks there may be a bacterial infection in your womb called chorioamnionitis, or if they are concerned about fetal anaemia. The test is often done during the second trimester of pregnancy to detect chromosomal issues, like Down syndrome, or to test for fetal lung function. This test is rarely performed in the United States after 24 weeks of pregnancy.

Amniocentesis is a simple and safe procedure that takes about 20 minutes and must be performed in the prenatal ward of your doctor. It results from an ultrasound to know the position of the baby and avoid puncturing Amniocentesis can give you more information about your growing baby, but it also carries a small risk of miscarriage or premature delivery. Sometimes the doctor will recommend inducing delivery if they discover an infection during the procedure.

• Pelvic exams: Pelvic exams are done to help your doctor decide if it is the right time to induce labour or let labour start on its own. Your health care provider may also do a test called amniotomy. This test helps find out how much amniotic fluid is still around your baby. Ripening is a process that takes place before labour begins. Your doctor will start doing pelvic exams again during the last few weeks of pregnancy.

During the third trimester, your health care provider will continue to perform routine exams. These may include a physical exam, checking your blood pressure and weight, and measuring the fundal height of your uterus.

Many factors such as age, race, and even the number of previous pregnancies can play a role in when your cervix starts to thin out and open. This can happen in the days or weeks before your expected due date. While there are some things you can do to help get cervical changes started if you are past your due date, it is often best to wait for labor to start on its own. Inducing labor at this stage may increase your risk of complications.

In the last three months of pregnancy, your cervix is preparing for labour by starting to efface and dilate. Cervical dilation is a way for doctors to test whether your body is ready for childbirth. If you are past 37 weeks and are 3 or more centimetres dilated, then your doctor will not be concerned. Talk with your doctor about how you can best prepare for birth in your final trimester.

Keep asking queries to your Doctor

During your third trimester, talk to your health care provider about how to recognize the signs of labor and how you will be informed when it is time to go to the hospital or birthing center. It is a good idea to confirm what number to call and when – whether it is day or night, who will answer the phone, and how quickly you can expect someone to respond. Discuss who needs to be notified if you give birth before your due date and who might be able to care for siblings while you are in the hospital. You may want to know when to call your health care provider and what happens during delivery. Learn more about third-trimester tests and ask a lot of questions.