What can a 22-week ultrasound show?

An ultrasound scan during pregnancy involves sound waves bouncing off of the fetus and structures in the body to create a rough picture. The scan is not a photo and cannot capture every detail.

The most common type is a 2D ultrasound, which offers a simple, somewhat grainy black and white image.

Process

During an ultrasound, the pregnant woman lies on a table. The healthcare provider, possibly a technician, applies gel to the woman’s bare abdomen.

They then use a handheld tool called a transducer to generate sound waves, and gently move the tool around the abdomen while checking the relayed images on a monitor.

For the best images, it may help to have a full bladder, which helps the sound waves to travel more effectively.

A vaginal ultrasound may offer a better image, especially when the fetus is in a certain position. This involves placing a thin transducer into the vagina.
This may cause pressure, but it should not be painful.

A 22-week ultrasound to check on the anatomy of the fetus may last about an hour.

During the anatomy scan, the healthcare provider will check:

• the number of fetuses, if this is the first ultrasound of the pregnancy
• the fetus’s organs, organ systems, and structures, including the brain, skull, heart, face, bones, hands, and feet
• for some congenital disabilities and some early signs of developmental issues
• the fetus’s sex, to see whether the genitals are developing in the usual way
• the health of the woman and the pregnancy, which may involve looking for signs of problems such as placenta accreta and placenta previa and measuring fluid levels

If an ultrasound technician performs the scan, they may not be able to answer questions. Instead, a doctor will meet with the woman shortly afterward to go over the results.

Ultrasounds cannot detect all pregnancy complications, and they may even suggest issues that are not there. In most cases, however, they are accurate — particularly if a skilled doctor analyzes the images and does a follow-up scan.

3D and 4D scans offer greater detail than traditional 2D ultrasound images.

A 3D ultrasound works by sending sound waves from multiple angles. This produces a 3D image, and the added detail makes it easier to see smaller structures, such as fingers and toes, as well as facial features.

A 4D ultrasound sends sound waves across multiple planes, with numerous waves per second. The result is an even more detailed image that makes it possible to see the fetus moving.

These scans may be standard, or facilities may offer them for an extra fee. A doctor might also order a 3D or 4D scan if they need more detail than a 2D scan is providing.

For example, if the fetus’s face looks unusual in a 2D image, the doctor might need added dimension to see whether the fetus has a cleft palate.

On a 3D or 4D ultrasound, a person might see:

• the fetus moving, kicking, or moving their mouth
• the fetus’s face, which may or may not resemble their appearance at delivery
• fine details of the brain, heart, and other organs
• the fingers and toes

While 3D and 4D scans may be common commercially, they are not frequently used for medical purposes in the United States.

The Food and Drug Administration (FDA) and pregnancy experts recommend avoiding any imaging that is not medically necessary.

The 22-week ultrasound can show the sex of the fetus, the development of their organs, and sometimes even the fetus’s face.

It can also give information about any health risks to the woman and indicate how the pregnancy is progressing. A woman and her doctor may start planning the delivery based on the results of the ultrasound.

Confirm with the doctor what the scan can and cannot reveal, and whether it will be possible to take a few images home.