Pregnancy Scans
Anomaly Scan / TIFFA Scan
Detailed check of your baby's organs and structure at mid-pregnancy
What is this scan?
The anomaly scan — also called the TIFFA scan (Targeted Imaging for Fetal Anomalies) — is the most comprehensive structural survey of your baby during pregnancy. Done at 18–22 weeks (ideally 19–20 weeks for the best image quality), it systematically checks every major organ system: the brain, face, spine, heart, lungs, abdomen, kidneys, bladder, limbs, umbilical cord, placenta, and amniotic fluid. It is the mid-pregnancy scan that most parents look forward to as a detailed 'health check' for their growing baby.
Why is it done?
The TIFFA scan is done to detect structural birth defects (anomalies) that can be identified by ultrasound at this stage. Many conditions — heart defects, neural tube defects, cleft lip, kidney problems — can be seen at 18–22 weeks. Early detection allows parents and medical teams to prepare: some conditions may be managed during pregnancy, some require delivery at a specialised hospital, and some allow parents time to seek counselling and make informed decisions. The scan also checks placental position (whether it might be covering the cervix — placenta previa), amniotic fluid volume, and estimates fetal size.
What to expect
The scan takes 30–60 minutes depending on the baby's position and cooperation. No fasting is required, though some centres recommend a light meal beforehand to encourage fetal movement. A gel is applied to the abdomen and the sonographer methodically checks each structure in a set protocol. If the baby is not in the right position, you may be asked to walk around, lie on your side, or return another day. Gender can be identified at this scan, but disclosure is regulated in India under the PCPNDT Act — your doctor follows legal guidelines about what can be communicated.
Normal findings
- ✓ All brain structures visible and normal: lateral ventricles, cerebellum, cisterna magna
- ✓ Lips and palate intact (no cleft lip detected on scan)
- ✓ Spine continuous, no neural tube defect
- ✓ Four-chamber heart view normal; outflow tracts visible
- ✓ Stomach bubble visible (baby swallowing — confirms oesophageal patency)
- ✓ Both kidneys present with normal echogenicity
- ✓ Bladder visible
- ✓ Umbilical cord with three vessels (two arteries, one vein)
- ✓ All four limbs present with expected number of bones
- ✓ Amniotic fluid index (AFI) 8–24cm — normal
- ✓ Placenta not covering the cervix (no placenta previa)
- ✓ Fetal growth within expected range for dates
When to be concerned
- Structural abnormality identified in any organ system — referral to fetal medicine specialist recommended
- Soft markers for chromosomal conditions: echogenic bowel, choroid plexus cysts, mild pyelectasis
- Placenta previa (placenta covering the cervix) — usually monitored with repeat scans; often resolves
- Oligohydramnios (low amniotic fluid) — may indicate kidney problems or growth restriction
- Polyhydramnios (excess fluid) — associated with GDM, oesophageal atresia, or fetal conditions
- Fetal growth below expected for dates — possible early growth restriction
Frequently asked questions
Will the doctor tell me the gender of my baby?
In India, disclosure of fetal sex is prohibited under the Pre-Conception and Pre-Natal Diagnostic Techniques (PCPNDT) Act, 1994. This law was enacted to prevent sex-selective abortions. Your doctor and the scanning centre are legally prohibited from telling you the baby's sex, and you should not ask them to do so.
Do I need to fast before the TIFFA scan?
No, fasting is not required. In fact, eating a light meal an hour before may help as a slightly active baby is easier to scan. However, avoid a very heavy or greasy meal. Some centres ask you to drink water to maintain amniotic fluid — follow your centre's specific instructions.
What happens if the scan shows a possible abnormality?
If a possible finding is identified, you will be referred to a fetal medicine specialist for a detailed repeat scan and counselling. A finding on the anomaly scan does not always mean a confirmed problem — some findings are soft markers that resolve, and some require further tests like amniocentesis for a definitive answer. Your doctor will guide you through the next steps.
Is the TIFFA scan 100% accurate in detecting abnormalities?
No. The TIFFA scan has a detection rate of approximately 60–80% for major structural anomalies, depending on the baby's position, equipment quality, and operator experience. Some conditions (especially heart defects and subtle brain changes) may not be visible even on a good scan. A normal TIFFA scan significantly reassures but does not guarantee a normal outcome.
What if I miss the 18–22 week window?
The scan can still be done after 22 weeks, but image quality and the ability to see certain structures decreases as the baby grows and there is less fluid around them. If you are beyond 24 weeks, your doctor will still arrange a detailed scan, but earlier is better.