Prenatal Ultrasounds: When and Why They’re Done

Prenatal care aims to ensure you and your baby stay as healthy as possible while your pregnancy progresses to term. Ultrasound screenings are an invaluable component of this vital care at Panhandle Obstetrics and Gynecology in Amarillo, Texas.

Ultrasound imaging allows your obstetrician to monitor fetal development and well-being — and keep tabs on your health — during pregnancy. It’s a safe, easy, and effective way to observe your growing baby and detect problems early, when they can often be corrected or minimized. 

Here, our obstetrics team discusses the ins and outs of pregnancy ultrasounds, including how many you might get, when, and why they’re so important. 

A short tutorial on pregnancy ultrasounds

A prenatal ultrasound — a fetal or pregnancy ultrasound — uses harmless soundwaves to produce sonogram images of your baby and uterus. The test is quick and straightforward: A handheld transducer emits high-frequency sound waves, which then bounce back to the device in the form of echoes. 

Ultrasound echoes paint a detailed picture of the internal structures they encounter, which the device then translates into live visual images in real time on a video monitor. 

How ultrasound supports prenatal care

A prenatal ultrasound provides visual information that helps your obstetric team check fetal health and development, monitor your pregnancy, and detect congenital anomalies. 

Besides giving us a way to confirm your pregnancy, ultrasounds can reveal complications related to fetal health as well as the pregnancy itself. 

For example, we can see whether your baby is growing as expected and detect serious problems with their brain, heart, kidneys, and bones. We can also spot problems with the location of the placenta (i.e., over your cervix) or amniotic fluid volume. 

Discovered early, these concerns can often be managed effectively to support a healthy pregnancy and protect fetal and maternal well-being. Essentially, the information we obtain from a fetal ultrasound helps us tailor our prenatal care to your specific needs. 

The typical prenatal ultrasound schedule 

Basic prenatal care in a normal, healthy pregnancy typically includes two standard ultrasound scans: One in the first trimester and another in the second. 

First-trimester ultrasound 

An early ultrasound scan is often done around week 8 of pregnancy but can take place as late as week 12. Known as a fetal dating ultrasound, we use this scan to rule out an ectopic pregnancy and: 

• Detect fetal heartbeat 
• Measure fetus size
• Estimate gestational age
• Confirm probable due date
• Check for twins or triplets

First-trimester ultrasounds are typically transvaginal, meaning the slender, wand-like transducer is covered in a latex sheath, lubricated, and gently inserted into your vagina. This ultrasound technique provides the clearest images in early pregnancy. 

Second-trimester ultrasound

In your second trimester, you can expect a standard ultrasound scan between 18-22 weeks of gestation. Known as a fetal anatomy scan or anomaly ultrasound, this scan reveals even more information about your growing baby. We use it to:

• Assess fetal heart activity
• Evaluate fetal movement 
• Estimate fetal size and weight
• Examine fetal development 
• Check amniotic fluid levels
• Study placental placement
• Reveal fetal gender if desired

An ultrasound anatomy exam involves checking the development of fetal organs (i.e., brain, heart, lungs, kidneys, bladder, stomach, intestines) and body parts (limbs, spine, face). We also check umbilical cord attachment and blood flow. 

We can detect signs and markers of common congenital anomalies at this stage, ranging from cleft palate and neural tube defects to Down syndrome and congenital heart disease. 

Starting in your second trimester, all ultrasounds are transabdominal, meaning we pass the transducer across your abdomen after lubricating your skin with a water-based conductive gel. 

When additional ultrasounds are advised 

If you have a healthy pregnancy and your standard ultrasound scans are normal, you likely won’t have any more fetal ultrasound screenings before you deliver — most pregnant women only have two prenatal ultrasounds. 

You may require additional ultrasounds, however, if:

• You have a high-risk pregnancy (i.e., multiples)
• You have a known or suspected health condition
• We suspect your baby has a health condition
• You have concerning symptoms (i.e., bleeding)
• You had complications in previous pregnancies

For example, we may perform a limited ultrasound to investigate vaginal bleeding, checking fetal heartbeat and the location of your placenta. Periodic specialized ultrasound exams can help us monitor your baby more closely if we notice a problem, like abnormal growth, on a standard ultrasound. 

Simply put, the health and progression of your pregnancy help determine the type and number of prenatal ultrasounds you may need. 

Your prenatal ultrasound imaging experts

Two-dimensional (2D) ultrasounds are the norm in prenatal care. Our team also offers dynamic three-dimensional (3D) ultrasound imaging — also known as a four-dimensional (4D) ultrasound. With 4D ultrasounds, you can view your baby in moving pictures, like a 3D video. 

To learn more about prenatal ultrasound exams, call us at 806-359-5468 to schedule a visit at Panhandle Obstetrics and Gynecology today.