One of the most exciting milestones of pregnancy is the second trimester anatomy scan, often called the 20-week ultrasound or mid-pregnancy anatomy scan. This detailed ultrasound gives you the opportunity to see your growing baby while allowing your healthcare provider to carefully evaluate your baby's development.

For many parents, it's also the appointment where they may learn their baby's sex, if they choose to find out. More importantly, this scan provides valuable information about your baby's anatomy, growth, placenta, and overall pregnancy health.

This guide walks you through what to expect, how to prepare, what your sonographer is looking for, and important questions you may want to ask.

The anatomy scan is a detailed prenatal ultrasound usually performed between 18 and 22 weeks of pregnancy.

Unlike earlier ultrasounds that focus primarily on confirming pregnancy and dating, this examination takes a comprehensive look at your baby's developing body and the pregnancy itself.

The goal is to assess your baby's growth and identify any findings that may require additional evaluation.

It helps your healthcare team check your baby's growth and development, evaluate major organs, measure bones and body parts, and assess the placenta.

It also checks amniotic fluid levels, evaluates the umbilical cord, confirms your due date if needed, screens for certain structural differences, and monitors your overall pregnancy.

Most anatomy scans are reassuring — many pregnancies have normal results.

Most women have their anatomy scan between 18 and 22 weeks pregnant.

This timing allows your baby to be developed enough for detailed imaging while still leaving time for follow-up testing if necessary.

Your provider will let you know if any preparation is needed. You may be asked to wear comfortable clothing, arrive a little early, and bring your insurance card and ID.

Drink water before your appointment if instructed — a moderately full bladder may improve imaging in some cases. Bring a support person if your clinic allows.

Policies on guests, children, photography, and video recording vary by clinic, so ask in advance.

The scan is usually performed with an abdominal ultrasound. You'll lie comfortably on an exam table, warm gel is applied to your abdomen, and the sonographer moves a handheld transducer over your belly.

Images of your baby appear on screen, and measurements are recorded for your healthcare provider to review.

The appointment typically lasts 30 to 60 minutes, though it may take longer if your baby is in a position that makes certain structures difficult to see.

Brain: brain structure, cerebellum, fluid spaces within the brain, and skull shape.

Face: eyes, nose, lips, and jaw — helping evaluate facial development.

Heart: heart chambers, valves, rhythm, and major blood vessels. Because the heart is constantly moving, it can take time to obtain all the necessary views.

Spine: examined from the neck to the lower back to assess development and alignment.

Abdomen: stomach, kidneys, bladder, liver, and bowel — evaluated for normal appearance and development.

Arms and legs: upper arms, forearms, thigh bones (femurs), lower legs, hands, and feet are measured to help assess growth.

Growth measurements commonly include head circumference, abdominal circumference, and femur length, compared with expected growth for your stage of pregnancy.

Placenta: location, appearance, and distance from the cervix (when relevant). If low-lying at this stage, a follow-up ultrasound may be recommended because the position often changes as the uterus grows.

Umbilical cord: number of vessels, cord insertion, and blood flow (when indicated).

Amniotic fluid: assessed to ensure it's within an expected range.

Cervix: often measured to help assess the risk of early cervical shortening or preterm birth, particularly with specific risk factors.

If your baby is in a position that allows visualization and you'd like to know, the anatomy scan may reveal the baby's sex.

Keep in mind: not every baby cooperates, position can make it difficult to determine, and some families choose to keep it a surprise.

Babies love to keep us guessing. If your baby is curled up, facing away, or moving constantly, the sonographer may ask you to change positions, walk for a few minutes, empty your bladder, or return for another scan to complete the exam.

This is common and usually isn't a cause for concern.

About growth: Is my baby measuring appropriately for my stage of pregnancy? Is growth on track? Are all measurements within the expected range?

About the scan: Were all of the baby's organs seen clearly? Did you obtain all the images needed? Does anything need to be rechecked?

About the placenta: Where is it located? Is it functioning normally? Will I need another ultrasound because of its position?

About amniotic fluid & cord: Is my amniotic fluid level within the expected range? Does the umbilical cord appear normal?

About my pregnancy: Any precautions I should take? Is it safe to continue exercising? When is my next visit? Will I need any additional testing or ultrasounds?

Hearing that additional imaging or testing is recommended can feel overwhelming, but many findings turn out to be minor or resolve on their own.

Sometimes a structure simply couldn't be seen clearly because of the baby's position. Follow-up ultrasounds are common and do not necessarily mean there is a serious problem.

Your provider will explain any findings, what they may mean, and whether further evaluation is recommended.

Your healthcare provider reviews the images and report, and results are discussed either during the visit or at a follow-up appointment.

If everything appears normal, you'll continue with your routine prenatal care. If additional evaluation is recommended, your provider will explain the next steps.

Can I eat before my anatomy scan? In most cases, yes — unless your provider gives specific instructions.

How long does the scan take? Usually 30 to 60 minutes, though it can take longer if extra images are needed.

Will I get pictures of my baby? Many clinics provide printed photos or digital images, but policies vary — ask your sonographer.

Is the anatomy scan safe? Ultrasound has been used in pregnancy for decades and does not use radiation. It's generally considered safe when performed by trained professionals for medical purposes.

Wear comfortable clothing, arrive a little early, and bring your list of questions.

Stay hydrated if instructed, and consider bringing a loved one if permitted.

Be patient if your baby needs extra time to cooperate — and celebrate this exciting milestone.

The anatomy scan is one of the most memorable moments of pregnancy — a chance to see your baby moving, stretching, and growing while your care team gathers important information.

Whether you discover your baby's sex, hear reassuring news, or simply enjoy watching your little one on the screen, this appointment is a meaningful step in your journey.

Every baby develops at their own pace, and not every scan goes exactly as planned. Trust your healthcare team, ask questions, and enjoy this special opportunity to connect with your growing baby.