Anomaly Scan (20-Week Scan): What It Checks and Why It Matters

One of the Most Important Scans

The anomaly scan — often called the 20-week scan, usually done between 18 and 22 weeks — is a detailed ultrasound that checks your baby's development in depth. It is a milestone many parents look forward to, and it is an important safety check as part of prenatal screening.

Dr. Sanjana L makes sure mothers across HSR Layout and Attibele understand what this scan is for, so it feels reassuring rather than nerve-wracking.

What the Scan Checks

The sonographer systematically examines:

• The brain and skull
• The face, lips and palate
• The heart and its major vessels
• The spine
• The stomach, bowel and kidneys
• The limbs, hands and feet
• The placenta position and the amount of amniotic fluid
• Your baby's growth and measurements

Why It Matters

The scan can detect many structural differences early, which allows for planning, further tests if needed, and the right specialist care to be arranged before birth. In the large majority of cases, it provides welcome reassurance that development is on track.

What It Does Not Do

The anomaly scan is not a guarantee that everything is perfect — some conditions cannot be seen on ultrasound. It also is not primarily a gender-reveal scan; in India, by law, the sex of the baby is not disclosed during pregnancy.

Preparing for the Scan

There is little to do beyond attending on time. The scan is painless and usually takes 20 to 45 minutes. If your baby is in an awkward position, you may be asked to walk around and return so the sonographer can complete all the views.

Frequently Asked Questions

At how many weeks is the anomaly scan done?

Usually between 18 and 22 weeks, most often around 20 weeks, when the baby's organs are well enough developed to examine in detail.

Is the anomaly scan safe?

Yes. Ultrasound is a safe, widely used part of pregnancy care with no known harm to you or your baby.

Will the scan tell me my baby's gender?

In India, disclosing the sex of the baby during pregnancy is not permitted by law, so this scan is used for medical assessment, not gender reveal.

What if the scan finds something?

Many findings are minor or need only monitoring. Where needed, your doctor arranges further tests and specialist input, and explains the next steps clearly.

Consult Dr. Sanjana L

Dr. Sanjana L (MBBS, MS — OBG, Gold Medalist) ensures your scans are done at the right time and their results explained clearly. Learn more about Dr. Sanjana, see her HSR Layout and Attibele clinics, or book an appointment.