Pregnancy is an exciting journey filled with milestones, and one of the most anticipated steps for many parents is seeing their baby through imaging technology. You’ve probably heard the “sonogram-ultrasound” duo used instead to mean the other, but is a sonogram and ultrasound the same thing? Here’s what these terms mean, their differences and what you can expect during pregnancy.
What Is the Difference Between Ultrasound and Sonography in Pregnancy?
An ultrasound is a medical imaging technique that uses high-frequency sound waves to produce images of the body’s internal structures. During pregnancy, it’s commonly used to monitor the health and development of your baby.
Sonography, on the other hand, refers to the process of using ultrasound technology to create images. The actual image produced by this process is called a sonogram. In essence:
- Ultrasound: The technology and process.
- Sonography: The practice of using ultrasound technology.
- Sonogram: The image produced.
So, while the terms are related, they aren’t exactly the same. Understanding these distinctions can help you better navigate discussions with your healthcare provider throughout the course of your pregnancy.
The Science Behind the Technology
Understanding how ultrasound works can help you appreciate this remarkable technology. The process begins when your sonographer applies a special gel to your skin. This gel helps eliminate air pockets between the transducer and your skin, ensuring clear sound wave transmission.
They then use a device called a transducer that emits high-frequency sound waves. These waves bounce off your internal structures, creating echoes that are converted into detailed images — your sonogram. It’s similar to how a camera captures a moment, but ultrasound uses sound waves to make the picture instead of using light. The transducer sends sound waves at frequencies much higher than human hearing can detect — typically above 20 kilohertz.
As these waves travel through your body, they encounter different types of tissue, each with varying densities. When the waves hit boundaries between tissues, they’re reflected to the transducer, while those that encounter no solid mass continue traveling deeper. The reflected waves create the basis for your sonogram image, with different tissue densities appearing in varying shades of gray.
The Role of Ultrasounds and Sonograms in Pregnancy
Medical imaging has revolutionized prenatal care, making pregnancy monitoring more comprehensive. In fact, pregnancy monitoring represents one of the most widespread applications of ultrasound technology in modern medicine. Healthcare providers regularly use these noninvasive scans to track your baby’s development, screen for potential complications and provide reassurance throughout pregnancy.
Types of Ultrasound Examinations
Different situations may call for various ultrasound techniques. The most common in pregnancy are:
- Obstetric ultrasound: The specialized pelvic ultrasound focuses on the uterus and fetus during pregnancy. It’s the foundation of most prenatal scans and includes standard imaging techniques and more detailed evaluations depending on the stage of pregnancy.
- Transvaginal: This internal ultrasound provides clearer images of your baby’s development early in pregnancy. Your healthcare provider gently inserts a specially designed transducer into your vagina to capture detailed images of your uterus and developing embryo.
- Transabdominal: This is the traditional ultrasound you’re probably most familiar with. Your provider applies gel to your abdomen and moves the transducer across your skin to capture images. This method becomes more effective as your pregnancy progresses.
- 3D and 4D ultrasounds: These advanced imaging techniques offer more detailed views of your baby. 3D ultrasounds create detailed, three-dimensional images of your baby. 4D ultrasounds capture moving 3D images, allowing you to see your baby’s movements in real time.
How Many Weeks Pregnant Do You Get a Sonogram?
Throughout your pregnancy, you’ll likely undergo several ultrasound examinations. The timing and frequency may vary based on your pregnancy and medical needs. However, there are typical milestones when ultrasounds are performed. Here’s what you can typically expect:
First Trimester — Weeks 6 to 13
Your first ultrasound usually occurs between weeks 6 and 8 of pregnancy. During this initial scan, your healthcare provider will:
- Confirm your pregnancy.
- Check your baby’s heartbeat.
- Estimate your due date.
- Screen for multiple pregnancies.
Some ultrasound centers also perform a nuchal translucency scan between weeks 11 and 13 to screen for chromosomal conditions.
Second Trimester — Weeks 14 to 27
The most anticipated ultrasound, the anatomy scan, typically occurs around week 20. During this detailed examination, your healthcare provider will:
- Examine your baby’s physical development.
- Determine your baby’s sex — if you choose to know.
- Check vital organs and structures.
- Evaluate the position of your placenta.
Third Trimester — Weeks 28 to 40
Additional ultrasounds during the third trimester aren’t routine for low-risk pregnancies but may be recommended if:
- Your baby’s growth needs routine monitoring throughout the pregnancy.
- You have pregnancy complications.
- Your placenta requires evaluation.
- Your healthcare provider needs to check your baby’s position before delivery.
Understanding Your Ultrasound Results
During your ultrasound appointments, your healthcare provider will take various measurements to track your baby’s growth and development. These include:
- Crown-rump length (CRL): This measurement helps determine your baby’s gestational age with remarkable accuracy in early pregnancy. It measures the length from the top of your baby’s head to their bottom.
- Biparietal diameter (BPD): Measuring your baby’s head circumference helps track brain development and overall growth. It becomes particularly important during the second trimester.
- Femur length (FL): By measuring your baby’s thigh bone, healthcare providers can estimate their height and check for proper bone development.
- Abdominal circumference (AC): This measurement helps track your baby’s growth and can indicate whether they’re receiving adequate nutrition.
After your ultrasound, your healthcare provider will discuss the findings with you. They may use terms like:
Within Normal Limits
This means your baby’s measurements fall within the expected range for their gestational age.
Percentiles
These numbers help compare your baby’s growth to other babies at the same gestational age. Being in a lower or higher percentile isn’t necessarily concerning. Your provider will explain what these numbers mean for your specific situation.
Follow-up Required
Sometimes, your provider might recommend additional scans to monitor specific aspects of your pregnancy. This doesn’t always indicate a problem but is a thorough monitoring of your baby’s development to ensure they miss nothing.
Common Misconceptions About Pregnancy Ultrasounds
It’s important to address some common misinterpretations about pregnancy ultrasounds:
Frequency of Scans
While some parents believe more scans are always better, the number of ultrasounds you’ll need depends on your specific situation and any potential risk factors. Your healthcare provider will recommend the appropriate number of scans for your pregnancy.
Gender Determination Accuracy
Though many parents are eager to learn their baby’s sex, remember that ultrasound accuracy for gender determination isn’t perfect. Factors like fetal position, gestational age and equipment quality can affect accuracy.
Commercial Ultrasound Services
While non-medical ultrasound facilities might offer attractive packages for “keepsake” images, these services shouldn’t replace medical ultrasounds performed by qualified healthcare professionals.
Preparing for Your Ultrasound
To make the most of your ultrasound appointment:
- Follow any specific instructions from your healthcare provider.
- Get a good night’s sleep before your appointment.
- Wear comfortable clothing and removable shoes.
- Arrive with a comfortably full bladder if requested.
- Bring your partner or support person.
- Consider asking for photos or videos if permitted.
The Future of Pregnancy Ultrasound Technology
As medical technology advances, new developments in ultrasound imaging are inevitable. These innovations include:
- AI-enhanced imaging: Artificial intelligence can help analyze ultrasound images more accurately and identify potential concerns earlier.
- Portable ultrasound devices: New compact ultrasound devices may make monitoring more accessible, especially in remote areas or for high-risk pregnancies requiring 24/7 frequent monitoring.
- Advanced 3D/4D capabilities: Improvements in 3D and 4D imaging technology continue providing clearer, more detailed views of developing babies, helping medical professionals and parents better understand fetal development.
Now You Know
Remember that ultrasound technology is just one tool in your prenatal care journey. While these images provide valuable information, they work alongside other prenatal tests and regular checkups to ensure your pregnancy progresses smoothly.
Stay engaged with your healthcare team, ask questions when needed and trust in the process. Your healthcare providers have extensive experience interpreting these images and will guide you through each stage of your pregnancy with expertise and care.
