The Mid-Pregnancy Anatomy Scan in Ajax: What to Expect

There is a common belief that the mid-pregnancy anatomy scan is mainly about finding out whether the baby is a boy or a girl. For many families, that question is part of the excitement, and that is perfectly understandable. But the anatomy scan is really one of the most thorough medical examinations a baby has before birth. It is a structured, organ-by-organ review, and understanding that can make the appointment feel more meaningful and a little less mysterious.

This post is for expecting parents in Ajax, Pickering, Whitby and across Durham Region who have been given a requisition for a detailed mid-pregnancy ultrasound. It walks through what the sonographer is generally looking at, why the appointment can run longer than you expect, and what a request for a follow-up scan usually means. For where this scan sits among the other ultrasounds of pregnancy, see our trimester-by-trimester overview.

Timing: why the middle of pregnancy

The anatomy scan is often done somewhere around 18 to 22 weeks, though your provider will advise on the timing that suits your pregnancy. There are practical reasons for this window. By then, the baby’s major structures have formed and are large enough to be seen in useful detail. At the same time, the baby is still small enough to be viewed in sections without being too crowded, and there is usually a good amount of amniotic fluid around the baby, which helps sound waves travel and makes images clearer.

Earlier than this, some structures are too small to assess well. Much later, the baby’s size, position and bones can make certain views harder to obtain. The middle of pregnancy tends to be a sweet spot, which is why so many care plans place a detailed scan here.

A head-to-toe tour of what is checked

Every facility follows a structured protocol so that nothing is skipped. While the exact list varies, a mid-pregnancy anatomy ultrasound generally includes views of the following areas. Knowing them helps explain why the sonographer keeps moving the probe and pausing.

Head and brain

The sonographer looks at the shape of the skull and takes measurements of the head. Several views of the brain are recorded to check that the main fluid spaces and structures look as expected for the stage of pregnancy.

Face

Views of the face may include the profile, the eyes and the upper lip. These are often among the trickier images to capture, because babies tend to put their hands near their faces or turn toward the uterine wall.

Spine

The spine is followed along its length in more than one direction, checking its alignment and the skin covering it. This takes careful positioning and sometimes a change in the baby’s posture.

Heart

The heart receives particular attention. The sonographer generally records the heart’s position in the chest, its chambers, and the major vessels leaving it. Heart views often need the baby to be lying in a helpful position, so this is a common reason for extra time or a return visit.

Chest and abdomen

Views may include the lungs, diaphragm, stomach, kidneys and bladder, and the area where the umbilical cord enters the baby’s abdomen. Seeing fluid in the stomach and bladder is part of the picture of how the baby is developing.

Arms, legs, hands and feet

The long bones of the arms and legs are measured, and the hands and feet are looked at. Counting fingers and toes is not always possible, as hands are often closed or tucked away.

Umbilical cord, placenta and fluid

Outside the baby, the sonographer usually documents the number of vessels in the umbilical cord, where the cord attaches, where the placenta is located, and how much amniotic fluid there is. In some cases, a measurement of the cervix may also be included.

Growth measurements

Throughout the scan, measurements of the head, abdomen and thigh bone are combined to estimate the baby’s size. These are compared with what is typical for the gestational age that was set earlier in pregnancy. If you are curious how that age was established in the first place, our article on the dating ultrasound explains it.

How the appointment usually unfolds

Because of all those views, the anatomy scan tends to be one of the longer ultrasounds of pregnancy. Here is a general picture of the visit:

1. Check-in. Bring your health card and requisition. You will confirm your details and any preparation instructions. At our Ajax clinic, parking is free and the entrance is on the ground floor, so there are no stairs to manage.
2. Settling on the bed. You will lie on your back, perhaps tilted slightly, with your abdomen uncovered. Gel is applied and the scan begins.
3. The structured survey. The sonographer works methodically through each area, often quietly, because concentration is needed to capture each standard view.
4. Pauses and position changes. You may be asked to roll onto your side, walk around briefly, empty your bladder, or simply wait while the baby moves. These are routine tricks to get a better angle.
5. Finishing up. Once the required images are captured, the gel is wiped away and you are free to go. The images are reviewed and a report is sent to the provider who ordered the scan.

It is very normal for the sonographer not to give a running commentary. Their focus is on obtaining complete images; interpretation and explanation come later through your provider.

Why a second visit is so common

Many parents are surprised, and some are worried, when they are asked to come back for another look. In most cases the reason is simple: one or more of the required views could not be captured clearly. Common causes include:

• The baby lying face-down or curled in a way that hides the heart or spine
• Hands or the umbilical cord covering the face
• An early stage of pregnancy where some structures are still small
• Tissue in the abdominal wall that makes sound waves travel less easily
• A placenta location that is worth rechecking later in pregnancy

An incomplete scan is about the picture, not necessarily the baby. A follow-up allows the team to complete the survey. If your provider has a specific reason for wanting another look, they will explain it to you, and you can ask what it means in your situation.

What an anatomy scan cannot do

It is worth being clear about the limits. An anatomy ultrasound is a valuable tool, but it cannot detect every condition, and some findings are only seen later in pregnancy or after birth. A normal scan is reassuring, but it is not a guarantee. Equally, an unexpected finding does not always mean a serious problem; many are followed up and turn out to be minor or to resolve. Your provider will guide any next steps and can refer you for additional assessment if needed.

Sex, keepsakes and the difference between the two

If you would like to know the baby’s sex, ask when you book and again at the start of the appointment, because whether and how it is shared at a diagnostic scan can depend on clinic practice and on whether the baby cooperates. If you would rather not know, say so clearly at the outset so the team can keep it private.

Some families also plan a separate keepsake session later on. Our 3D/4D ultrasound is an optional experience, often booked between about 23 and 28 weeks for the clearest facial views, with family and friends welcome. It is a lovely addition, but it never replaces the diagnostic anatomy scan your provider has arranged. For more on timing a keepsake session, see the best time for a 3D/4D ultrasound.

Frequently asked questions

Do I need a full bladder?

Requirements vary. Many mid-pregnancy scans do not need a very full bladder, but some facilities ask for a moderately full one. Follow the instructions you receive with your appointment, and call us if you are unsure.

Can my partner or a support person come in?

Many patients bring a support person. Please call ahead to confirm current guidance on guests in the exam room for diagnostic scans, as this can differ from a keepsake session.

Will I get pictures to take home?

This depends on the type of exam and clinic practice, so ask when you book rather than assuming.

How long will the scan take?

It varies with the baby’s position and how easily views can be obtained. Plan for a longer visit than an early pregnancy scan, and avoid booking anything tightly afterwards.

I live outside Ajax. Can I still book here?

Yes. We regularly see patients from Pickering, Whitby, Oshawa, Clarington and eastern Toronto. Our areas we serve page lists the communities we welcome.

When not to wait for your appointment

Your anatomy scan is a scheduled check, not an emergency service. In the second trimester, contact your health-care provider promptly, or go to the hospital or emergency department, if you have vaginal bleeding, fluid leaking from the vagina, severe or persistent abdominal pain, regular cramping or tightening, a severe headache with vision changes, or a fever. Call 911 if you feel very unwell. Do not hold symptoms until your scan.

Booking your anatomy scan

Obstetrical ultrasound is part of our ultrasound service at Rossland Diagnostic Clinic, Unit 102, 300 Rossland Road East, Ajax. We have free parking and ground-floor access, and we are open Monday to Friday from 9:00am to 5:00pm and Saturday from 8:00am to 3:30pm. When you have your requisition, call us at 905-426-3111 or request an appointment. Give yourself a relaxed morning or afternoon for this one; it is worth not rushing.