Special Fetal Testing in Your Third Trimester
The third trimester of pregnancy begins around week 28. With only three months left in your pregnancy, your prenatal appointments will pick up in frequency. Instead of visiting the doctor every month, you’ll have an appointment every two weeks from week 28 through 36 and then every week throughout the rest of your pregnancy.
Many of the appointments during the third trimester are routine appointments, which means your vital signs and fundal height will be taken but little else will be done. The exceptions to this are the diabetes screening already discussed here on the blog, the group B strep screening that we’ll discuss in our next blog post, and special fetal testing that you may need or want.
Why you might need special fetal testing
After 32 weeks of pregnancy the doctor will monitor you closely for potential problems, especially if you are at risk for delivering a stillborn baby or have any of the following problems:
- Blood disorders
- Thyroid disease
- Heart disease
- Kidney disease
- High blood pressure
- Decreased fetal movement
- Too much or too little amniotic fluid
- Fetal growth problems
- Post-term pregnancy
- Multiple pregnancy, if there are complications
Types of special fetal testing
Most special fetal testing will check to see how active the baby is and how the baby is growing. The following is a brief overview of each test.
Fetal movement counts: This testing takes place at home and is up to you to complete. I will give you more specific instructions, but you’ll basically need to relax on your back for awhile and count the number of kicks/movements you feel. You should be able to count to 10 within two hours.
Nonstress test: Using electronic monitoring, we make an assessment of the baby’s health by comparing movements to heart rate.
Ultrasound: I often recommend an ultrasound to determine the size and position of the baby somewhere around 34 weeks of pregnancy. (Learn more about prenatal ultrasounds.)
Doppler ultrasound of the umbilical or other artery: This special ultrasound checks for blood flow and is done when the baby is at risk for anemia.
Biophysical profile (BPP): Combining a nonstress test and ultrasound, the BPP assesses the health of the baby when you’ve gone past your due date or your baby is not growing the way I would like.
Contraction stress test: Not done often, the contraction stress test measures heart rate when the uterus contracts.
This is one of several articles published as part of a series to discuss what moms-to-be can expect in Connecticut prenatal care. Check back regularly for more information.