Two-thirds down, one-third to go!

Your routine tests will now be accompanied by procedures that evaluate your baby's health in anticipation for his or her grand arrival.

As always, make sure you talk with your health care provider and fully understand all that is involved before you decide to proceed with any procedure.


What is it?

Using high frequency sound waves, a gel is first rubbed on the woman’s belly, and then a transducer is moved across the belly, producing sound waves that bounce off bones and tissue, providing pictures of the baby (a sonogram).

When is it performed?

Unless you’ve been having routine ultrasounds, you’ve probably been counting the weeks since your last ultrasound, eager to see your little one on screen again! In this third trimester, most women have an ultrasound at 32 weeks. Additional ultrasounds are usually only performed if you go past your due date.

What does it look for?

Your doctor will now be looking to assess your baby’s weight and to make sure that your placenta is in the proper position (not covering the cervix, which would indicate placenta previa).

Who should have the procedure?

All pregnant women can benefit from an ultrasound at some point in their pregnancy.

Why do it?

An ultrasound can give your doctor the most accurate look at your baby’s development and growth – not to mention what’s going on with you.

Why wouldn’t I do it?

When used correctly, ultrasound machines emit less energy than a fetal Doppler. However, if the ultrasound technician is not a physician or trained sonographer, it is wise not to risk exposure to an unknown level of sound waves.


Your doctor will continue to monitor your urine for excess protein, sugar, ketones and/or bacteria.

GROUP B STREP (aka Group B Streptococcus (GBS))

What is Group B Strep?

The group B strep bacterial infection is present in 15 to 40% of all healthy women. During childbirth, a woman who is not receiving antibiotics can pass it along to her baby.

According to the Center for Disease Control, group B strep is “the most common cause of life-threatening infections in newborns.”

How is the procedure done?

Your health practitioner will swab your vagina and rectum to screen for this bacterial infection. If you test positive, you will be given intravenous antibiotics during labor so that you won’t pass along the infection to your baby.

When is it performed?

Between weeks 35 to 37.

Who should have this test?

Every pregnant woman should have this test.


What is it?

This screening test involves a blood test that is performed an hour after you have consumed a sweet, syrupy glucose (sugar) "beverage". If your blood sugar level is high (results will come back in a few days), you’ll need to take a glucose tolerance test, a similar test that takes a bit longer (about three hours).

When is it performed?

Between weeks 24 to 28.

What does it look for?

This screening test looks for gestational diabetes, a form of diabetes that develops during pregnancy.

Who should do the test?

All pregnant women should screen for gestational diabetes.

Additional Notes

Diagnosing and treating gestational diabetes is extremely important. Untreated gestational diabetes can affect the weight of your baby, increase the risk of a C-section, possibly cause complications during labor or could lead to your baby developing diabetes later in life. It can also make babies disproportionately bigger and may lead to a shoulder dystocia, or it could lead to hypoglycemia in the baby, which can lead to seizures.


What is it?

The non-stress test measures your baby’s fetal heart rate, both at rest and during movement, by attaching a monitor to the mother’s belly. Monitoring is done for 20 to 30 minutes, noting any fetal distress.

When is it performed?

This test can be done if you have gone past your due date or during your third trimester if you are having a high-risk pregnancy or if your baby’s movement is not as frequent as it has been.

Who needs it?

As mentioned above, this monitoring is usually done for expectant moms who have gone past their due date. However, sometimes it is performed if you have certain risk factors like gestational diabetes.


What is it?

A "BPP" is a non-stress test, accompanied by an ultrasound, to assess your baby’s health. Specifically, the BPP looks at your baby’s physical movement, breathing movement, the tone on the baby, and amniotic fluid levels. Rated on a scale of 1-10, the results of a BPP can indicate whether or not a C-section is advisable.

Do I need a biophysical profile?

A biophysical profile is usually performed if your non-stress test delivered less than desirable results.

CONTRACTION STRESS TEST (aka The Oxytocin Challenge Test (OCT))

What is it?

This test monitors how your baby reacts during uterine contractions, since contractions lower his/her blood and oxygen supply. Seeing how your baby handles these conditions can be a good indicator of how s/he will handle labor.

When is it performed?

Usually late in the third trimester.

Do I need a contraction stress test?

Your doctor will probably only perform a contraction stress test if your non-stress test and biophysical profile returned abnormal results.

The following conditions, disorders and diseases are mentioned above:

Placenta Previa: When the placenta is abnormally lying in the lower section of the uterus, completely or partially covering the cervix, which would hinder a vaginal delivery.Spina Bifida: A neural tube birth defect where the spinal column doesn’t completely close (occurs in the first month of pregnancy).

Cystic Fibrosis: A hereditary disease that affects the lungs and digestive system — often leading to early death.

Down Syndrome: A genetic disorder where an individual has an extra 21st chromosome, resulting in some mental retardation.

Tay-Sachs Disease: A genetic disorder high among those of Askhenazi Jewish or Eastern European descent resulting in neurological deterioration and early death in children.

This article was reviewed by Anthony Chin, MD. Dr. Chin is an OB/GYN in Beverly Hills, California.