Ultrasound in Pregnancy: What to Expect Each Trimester

Ultrasound is the primary imaging tool used during pregnancy. It uses sound waves — not radiation — to create real-time images of your baby. It is safe for both mother and baby and provides your doctor with essential information at every stage of pregnancy.

Here is what to expect during ultrasound exams in each trimester at Advanced Medical Imaging.

First Trimester (Weeks 1–12)

What the Scan Checks - Confirm the pregnancy — verify that the embryo is in the uterus (not ectopic) - Heartbeat — the heart is usually visible by 6 to 7 weeks - Due date — measuring the embryo gives the most accurate estimated due date - Number of babies — twins or multiples are detected early - Viability — confirming the pregnancy is progressing normally

What You Will See At this stage, the baby is very small — sometimes just a flickering dot (the heartbeat) inside a small sac. You may have a transvaginal ultrasound (a small probe inserted into the vagina) for the best views in early pregnancy.

Nuchal Translucency Screening (11–13 Weeks) This specialized ultrasound measures the fluid at the back of the baby's neck. Combined with blood tests, it screens for Down syndrome and other chromosomal conditions. The American College of Obstetricians and Gynecologists (ACOG) recommends this screening be offered to all pregnant women.

Second Trimester (Weeks 13–26)

The Anatomy Scan (18–22 Weeks) This is the most detailed ultrasound of your pregnancy. Often called the "20-week scan," it checks:

• Brain, spine, and skull development
• Heart — all four chambers and major blood vessels
• Face — lips, nose, and eye sockets
• Organs — kidneys, stomach, bladder, and diaphragm
• Limbs — arms, legs, hands, and feet
• Placenta — location and health
• Amniotic fluid — too much or too little can indicate problems
• Gender — if you want to know (and if the baby cooperates!)

What You Will See By 20 weeks, you will see a recognizable baby profile, fingers, toes, and often movement. Your sonographer will point out key structures during the exam.

Cervical Length Check If you are at risk for preterm labor, your doctor may order a transvaginal ultrasound to measure your cervix length during the second trimester.

Third Trimester (Weeks 27–40)

What the Scan Checks - Baby's position — head down (vertex) or breech - Growth — estimated fetal weight to make sure the baby is growing on track - Amniotic fluid levels — monitored closely in the final weeks - Placenta location — confirming it is not blocking the birth canal (placenta previa) - Biophysical profile — combines ultrasound with fetal heart monitoring to assess well-being

What You Will See At this stage, the baby fills most of the screen. You may see the face, yawning, thumb-sucking, or hiccups. Because the baby is larger, it can be harder to get a full-body picture.

Non-Stress Tests with Ultrasound In high-risk pregnancies, your doctor may order regular ultrasound monitoring along with fetal heart rate testing to ensure the baby is thriving.

How to Prepare for a Pregnancy Ultrasound

• First trimester: You may be asked to drink water and arrive with a full bladder, which helps create a clearer image
• Second and third trimester: Usually no special preparation needed
• Wear comfortable, two-piece clothing so your abdomen is easily accessible
• Bring your partner or support person — seeing the baby together is a special moment

Is Ultrasound Safe During Pregnancy?

Yes. According to the FDA, diagnostic ultrasound has been used safely during pregnancy for decades. It does not use ionizing radiation, and no harmful effects have been confirmed when used by trained professionals for medical purposes.

That said, medical organizations recommend against non-medical "keepsake" ultrasounds performed by non-clinical staff.

Prenatal Ultrasound in Seminole, FL

At Advanced Medical Imaging, our experienced sonographers provide detailed prenatal ultrasound using advanced equipment. All scans are reviewed by board-certified radiologists, and results are sent to your OB/GYN promptly.

Call (727) 398-5999 or schedule online.