The last trimester of pregnancy is a crucial time filled with anticipation and joy. And as you prepare to welcome your little bundle of joy into the world, there are some essential scans and tests that you should know about to ensure both your and your baby’s well-being
From measuring your baby’s growth and position to monitoring your health, these scans and tests play a crucial role in keeping both mum and baby in tip-top shape.
In this article, we will be talking about the scans and tests that you should have during your third trimester. You may be advised to undergo all tests, or it will depend on your pregnancy and your condition.
Table of Contents
Third Trimester Scans and Tests
Checking on Baby
Throughout your pregnancy, you will want to know how your baby is growing. Prenatal tests and scans can offer valuable information about your health and your baby.
During your prenatal visits in the third trimester, you will have to undergo weight and blood pressure checks. Your doctor or midwife will measure the size of your uterus (fundal height) and feel your belly. This is for checking your baby’s growth and position.
Later in the third trimester, you may have a fetal ultrasound to know your baby’s weight, check if there are any irregularities with his movement, and confirm your baby’s position. your doctor or midwife will check to see how your baby’s head drops nearer to your pelvis.
If your baby is not head-down after 36 weeks, your care provider may try an approach to gently move the baby into a head-down position.
Electronic fetal heart rate monitoring is usually for confirming if the baby is healthy. This type of monitoring is also needed during labour and delivery. You might have this monitoring after the 2oth week of gestation while having your prenatal checkups.
Image Source: iStock
Checking on Mum
1. Checking Cervical Dilation
Towards the end of your pregnancy, your doctor may perform a cervical exam to check if your cervix has started to dilate or open. This helps determine if labour is approaching or if any interventions are needed.
2. Pelvic Width Exam
The pelvic width exam evaluates the size and shape of your pelvis to assess if it can comfortably accommodate the baby during childbirth. It aids in understanding the birthing process and ensures a safe delivery for both you and your little one.
3. Complete Urine Examination
A complete urine examination helps monitor your kidney function and identifies any signs of urinary tract infections or other complications. Timely detection and treatment can prevent potential issues during pregnancy.
4. Blood Chemistry Tests
Blood chemistry tests are essential for assessing your overall health during the third trimester. These tests check for conditions like anaemia, gestational diabetes, and other metabolic disorders that may affect your pregnancy.
5. Blood Pressure Monitoring
During the third trimester, regular monitoring of your blood pressure is essential. High blood pressure, also known as hypertension, can develop during pregnancy and may lead to serious health problems if left untreated. It hinders blood flow to vital organs, such as the uterus and placenta, potentially resulting in fetal growth restriction and early delivery.
If gestational hypertension is left untreated or worsens, it can progress to a more severe condition called preeclampsia. Preeclampsia is characterized by high blood pressure and protein in the urine and can have life-threatening consequences for both the mother and the baby.
These tests are vital components of antenatal care, providing valuable insights into your health and your baby’s development. Regular check-ups and monitoring in the third trimester help ensure a smooth and safe pregnancy journey.
If your doctor recommends a scan or test, make sure that you will learn about the risks and benefits. Most mums find that prenatal checkups offer them peace of mind while in preparation for their baby’s arrival. But, it will be always your choice to accept or decline a test.
Common Scans and Tests During Your Third Trimester
During the last trimester of pregnancy, your doctor may suggest that you have certain diagnostic tests. These recommended tests are all safe and will ensure the optimised welfare of both the mother and baby.
The following are some of the most common tests pregnant women should have:
1. Group B Streptococcus screening
Group B Strep (GBS) is a type of bacteria that exists in the female reproductive tract without causing symptoms. An estimated 30 per cent of healthy women may carry GBS, and usually, it does not cause any health problems.
However, sometimes it might lead to a serious infection in the bloodstream, infection of the placenta, or urinary tract infection. Group B Strep can also have serious consequences for the baby, causing potentially life-threatening infections in the newborn. These infections might include meningitis, pneumonia, and sepsis.
Testing is simple and may involve taking a sample from the vagina and from the rectum using a cotton swab. The swab to be used is cultured in the laboratory to see if GBS is present.
If the result is positive, your doctor may give you antibiotics during labour to reduce the risks of infection in the baby. The test is usually done between the 35th and 37th weeks of pregnancy.
2. The non-stress test (NST)
The non-stress test or NST involves a fetal monitor strapped to your abdomen to quantify the baby’s heart rate as it moves. This test is called non-stress because literally, no stress is placed on the baby for the test.
Additionally, this test is performed on a weekly basis in high-risk pregnancies. It is administered after the 28th week of pregnancy, though most commonly after 32 weeks. Usually, a doctor may take measurements of your baby’s heart rate for 20 to 30 minutes.
Furthermore, an NST may be recommended if you feel the baby moves oddly or is not normal. This is recommended by the doctor if you are past the due date, or if the doctor wants to ensure the placenta is healthy and functioning well.
There are no known issues with the NST for both the mother and baby.
3. A biophysical profile
A biophysical profile (BPP) synthesizes the information from an NST with an ultrasound scan of the baby for a more precise evaluation.
4. A contraction stress test
A contraction stress test or CST, like the NST, quantifies the fetal heart rate. However, in this test, your baby’s heart rate is measured in response to uterine contractions that are extracted through giving oxytocin or by stimulation of the nipples.
The test is sometimes called as oxytocin challenge test.
Third Trimester Ultrasound Scans
An ultrasound is a safe and painless test that uses sound waves in making images that show your baby’s shape and position in the uterus.
An ultrasound scan may be performed in the third trimester if needed to aid in evaluating your baby’s growth and look for problems with the placenta. Sometimes, it may be a part of BPP to see whether your baby is getting enough oxygen.
Mothers with results in tests of high-risk pregnancies might have multiple ultrasound scans in their third trimester.
- If medically the baby may feel larger or smaller than expected during the gestation
- When the mother has a medical condition that could influence the baby’s growth and well-being
- If the placenta was low-lying on the mid-trimester ultrasound
- When a doctor is unsure of the baby’s fetal head position
- If there is pain or bleeding
- When the fetus is not moving well
- If a fetal abnormality was noted on an earlier ultrasound
- Fetal anatomy, although late in pregnancy, the views of the baby’s parts may be difficult to see.
- fetal position
- placental position
- fetal size
- baby’s welfare
- The blood flow in the umbilical cord gives an idea of placental function.
Image Source: iStock
Here at theAsianparent Singapore, it’s important for us to give information that is correct, significant, and timely. But this doesn’t serve as an alternative for medical advice or medical treatment. theAsianparent Singapore is not responsible for those that would choose to drink medicines based on information from our website. If you have any doubts, we recommend consulting your doctor for clearer information.