What Does a 20-Week Anatomy Scan Actually Look at? Everything You Need to Know

Reaching the halfway point of pregnancy brings one of the most exciting and widely anticipated appointments on your prenatal care calendar. The fetal anatomy scan at 20 weeks gives your healthcare provider a thorough look at your baby's developing body. For many parents, this is also the moment they confirm the baby's sex. Understanding what this scan covers helps you walk in feeling prepared, informed, and confident.

Why the 20-Week Scan Matters

The fetal anatomy scan at 20 weeks is a standard, essential, and routine part of prenatal care. It gives doctors a structured opportunity to assess fetal growth, check organ development, and identify any concerns well before birth.
Unlike earlier scans focused on confirming the pregnancy or estimating due dates, this one is detailed and highly methodical. Each part of your baby's body is reviewed systematically from head to toe throughout the appointment.

What the Sonographer Is Looking For

Your sonographer follows a standard, comprehensive checklist during the fetal anatomy scan. Each structure on that list gives your care team useful information about how your baby is growing and developing inside the womb this week.

The Brain and Skull

The sonographer examines your baby's brain structures carefully and very methodically during this appointment. The cerebral ventricles, cerebellum, and the fluid-filled spaces around the brain are measured and observed to confirm healthy neurological development at this stage.
The shape and size of your baby's skull are also carefully evaluated by the sonographer. Any unusual findings in these areas are noted for further follow-up with your doctor or a maternal-fetal medicine specialist if needed.

The Face and Neck

Facial features, including the eyes, nose, lips, and profile, are checked for structural completeness and proper formation. The sonographer looks for signs of a cleft lip or palate, which can be detected during a careful facial view.
The neck is assessed for any unusual fluid accumulation or structural irregularities. This part of the scan is quick but important, as certain findings in this area can indicate chromosomal or developmental considerations worth monitoring closely.

Your Baby's Heart

Cardiac assessment is one of the most detailed and thorough portions of the scan. The sonographer checks the four chambers of the heart, the valves, and the major blood vessels entering and exiting the heart.
A properly formed heart at 20 weeks shows clear separation between chambers and normal outflow tracts. Congenital heart conditions are among the most common fetal abnormalities, making this part of the scan especially important to complete.

Your Baby's Spine

Your baby's spine is carefully examined from multiple angles throughout this detailed scan. The sonographer looks at each vertebra along the length of the spine to check for conditions such as spina bifida or other neural tube defects.
The scan assesses both the bony structure of the spine and the overlying skin. A closed spine with intact skin covering is the normal, expected finding that sonographers are looking for at this gestational stage.

The Abdomen and Organs

The stomach, kidneys, bladder, and bowel are each carefully evaluated during the abdominal portion of the scan. The stomach should appear as a small fluid-filled bubble, confirming that the baby is swallowing amniotic fluid normally.
The kidneys are measured, and the bladder is observed carefully for signs of normal filling. The abdominal wall is also closely checked to ensure all organs are properly contained within the body and not protruding outward.

The Limbs and Hands

Each arm and leg is carefully measured and observed during the scan. The sonographer checks the long bones of the limbs, including the femur, humerus, tibia, and fibula, to assess proper growth proportional to gestational age.
Hands and feet are also observed when the baby's position allows for a clear view. While counting individual fingers and toes is not always possible, the sonographer looks for normal structural formation of the hands and feet.

The Placenta and Amniotic Fluid

The exact position of your placenta is carefully recorded and noted during this scan. Placenta previa, a condition where the placenta covers the cervix, can be identified and monitored throughout the remainder of your pregnancy.
Amniotic fluid levels are also measured and carefully evaluated. Too little or too much fluid can point to potential complications, so this measurement gives your care team a useful snapshot of your baby's overall environment and health.

Making the Most of Your Scan

The fetal anatomy scan at 20 weeks covers far more ground than many parents expect. From brain development to placental position, every detail contributes to a fuller picture of your baby's health. Whether you schedule through your OB or choose an additional elective session with a studio like Tummy Vision, arriving prepared makes the experience more meaningful. Bring your questions, stay hydrated, and enjoy this remarkable milestone in your pregnancy journey.