What Is An Fetal Anomaly Scan?

An Fetal anomaly scan is an ultrasound scan taken around 20 weeks of your gestation. This scan gives detailed information on possible structural abnormalities in your baby’s  organs, the amniotic fluid level and the placental position.

An Fetal anomaly scan is the first indicator of possible abnormalities during pregnancy and is also called a mid-pregnancy ultrasound scan. 


Detailed information on all these is to be discussed in the later sections of this page.

During an anomaly scan procedure, special attention is given to the anatomy of the skull, brain structure, face, two eye orbits with lens, nose, lips, chin, heart structure, lungs, stomach, two kidneys, intestines, bladders, segments of limbs, hands and toes. 

A  baby’s ears and the number of fingers and toes are examined only if there are any abnormalities with the other mentioned parts. In addition, this is also examined if you have a genetic disorder in your family

Best Anomaly Scan Centre in Chennai

Jammi Scans at T. Nagar  is the top choice for Anomaly Scan in Chennai by many moms-to-be. Getting your anomaly scan at Jammi Scans means you can entrust your baby’s welfare in the hands of an award-winning Obstetrician and Gynecologist in the city, Dr Deepthi Jammi.

When Will The Anomaly Scan Procedure Be Done?

To be precise, an anomaly scan procedure can be taken anytime between the 18th and 22nd week of pregnancy.

Hence, it is also termed “Mid-pregnancy scan”. This is one of the common routines of your antenatal care.

Will The Anomaly Scan Provide 100% Confirmation Of The Structural Development?

The answer is NO.

While most babies are born healthy, only a small percentage of them stand the risks of developing complications. An anomaly scan cannot detect such complications that evolve during the later phases of gestation.

That’s why people say that even a normal anomaly scan cannot guarantee a healthy baby.

What If There Are Signs Of A Problem In An Anomaly Scan?

If your ultrasound anomaly scan shows any abnormalities, the defect revealed will be studied in detail. Following this, Your doctor will offer you genetic counseling.

This is to discuss your family history to check if anybody had the same abnormality as your child. A repeat scan is done during the later stages of your gestation might be recommended.

You may also be offered the option of undergoing an amniocentesis test for chromosomal abnormalities.

How Can Patients Prepare For An Anomaly Scan?

Unlike the first trimester scans, patients don’t need a full bladder for this scan. The baby is now big enough and high enough in the abdomen to be seen very clearly by a scan conducted via the abdomen.

The only prerequisite for an anomaly scan would be a mom’s strong belief to deliver a healthy baby. Be confident in the suggestions recommended by your healthcare provider if guided with other treatment options.

What does your Fetal Medicine specialist examine during an anomaly scan?

The ultrasound waves help with a black and white 2-D image of your baby. This helps your fetal specialist carefully examine all the vital organs and take the measurements.

These are some of the examinations done,

Will the baby's weight be included in the Anomaly Scan Report Details?

In addition to the above details, your anomaly scan report details three other measurements done to gauge the baby’s growth and weight:


The measurements taken during the anomaly scan should match upto what’s expected for the baby, depending on when the due date is. 

Abnormal conditions are extremely serious, which may mean that a baby can’t survive. Or they may be treatable conditions, once the baby is born. If the condition is treatable, the fetal medicine specialist will collaborate with the obstetrician to enable adequate care once the child is born.

Fetal parts not mentioned under the ISUOG guidelines are not evaluated in an anomaly scan.

Can Down syndrome or chromosomal abnormalities be identified in the anomaly scan?

Only an amniocentesis test (testing the fluid surrounding the baby for its chromosomes) done during the first trimester can diagnose Down’s syndrome perfectly. In comparison, the ultrasound anomaly scan detects just 30% to 50% of cases of Down syndrome.

Sometimes babies with chromosomal abnormalities have signs called ultrasound markers. These include thick skin behind the neck (nuchal fold), absent nasal bone, mild fluid within the brain’s ventricles, an aberrant subclavian artery in the neck, occasionally short arms or legs. It is important to note that many normal babies also show these signs. The only way to accurately exclude or diagnose a chromosomal problem is to have an amniocentesis test.

Limitations of the anomaly scan

Frequently Asked Questions

An anomaly scan is usually done between 18 and 22weeks of gestation. A fetal structure abnormality scan done anytime before this period shows only 22% accuracy.

You can take the anomaly scan during any time of the day without fasting or getting the bladder full. With the help of an ultrasound probe, your sonographer will be able to view a black and white 2-D image of your baby on the screen. Your baby’s essential body anatomy, placental position, and amniotic fluid levels are checked with the ultrasound waves.

The total scan procedure approximately takes about 30minutes to complete. If additional tests are required, this might extend briefly.

No. Anomaly scans are not painful. 

Chennai Women’s Clinic being one of the best places for anomaly scan in Chennai gives the assurance of taking one step further in providing the most comfortable, safe, and clean scanning experience.

We are quite fast (10 – 15minutes approximately) in delivering your report. Your reports are generated parallelly when your scan is done. We make sure all your photo reports are laminated for you to treasure them for a lifetime

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