Pregnancy Scan Schedule: Which Ultrasound in Which Month? (Delhi Guide 2026)

Every visit seems to end with a new slip of paper and a new scan name — dating, NT, double marker, TIFFA, growth, Doppler — and nobody has sat down and explained how they fit together. It is one of the most common sources of quiet anxiety in pregnancy, and it is entirely avoidable.

This guide lays out the whole picture in order: which scan is usually advised in which month, the exact week window each one needs, what it actually checks, and — just as importantly — what it cannot tell you. One honest note before we begin: your obstetrician decides your personal schedule. Every pregnancy is different, and this is a map to help you understand the journey, not a checklist to follow on your own.

The quick answer

Most uncomplicated pregnancies in India involve three to five ultrasound scans, spread roughly like this: a dating scan in the first weeks, an NT scan at 11–13+6 weeks (usually with a double marker blood test), the anomaly or TIFFA scan at 18–22 weeks, and one or more growth scans with Doppler from about 28–32 weeks. Anything beyond these is added only when there is a specific medical reason. Each scan has a fixed window — done too early or too late, it simply cannot do its job.

The pregnancy scan schedule at a glance

When	Scan / test	What it checks
6–9 weeks	Dating / viability scan	Pregnancy inside the uterus, heartbeat, accurate due date, single or twins
11–13+6 weeks	NT scan + double marker	Chromosomal risk screening, early anatomy
11–14 weeks (only if advised)	CVS	Diagnostic genetic test after high-risk screening
14–20 weeks (if first-trimester screening missed)	Quadruple marker	Second-trimester chromosomal risk screening
15–20 weeks (only if advised)	Amniocentesis	Diagnostic genetic test
18–22 weeks	Anomaly / TIFFA scan	Detailed head-to-toe check of the baby’s structure
18–24 weeks (only if advised)	Fetal echocardiography	Detailed study of the baby’s heart
28–32 weeks	Growth scan + colour Doppler	Growth, fluid, placenta, blood flow to the baby
36 weeks onwards (as advised)	Growth scan / Doppler	Growth, position, fluid, wellbeing before delivery

First trimester (weeks 1–13)

Dating / viability scan — around 6 to 9 weeks

This first scan answers the questions that matter most at the start: is the pregnancy in the right place (inside the uterus), is there a heartbeat, is it one baby or more, and — crucially — what is the accurate due date. Early measurement gives a far more reliable date than counting from your last period, and every scan that follows is timed from it. Get this one right and the whole schedule falls into place. Read more in our dating scan guide.

NT scan + double marker — 11 weeks to 13 weeks 6 days

The NT (nuchal translucency) scan measures a small fluid space at the back of your baby’s neck, and is usually paired with the double marker blood test. Together with your age, they produce a single risk estimate for Down syndrome and a few other chromosomal conditions.

Two things are worth understanding clearly. First, the window is strict — the measurement is only reliable when the baby’s crown-rump length is roughly 45–84 mm, which is why the date is not flexible. Second, this is a screening test: it estimates a chance, it does not diagnose. A higher-risk result is not a diagnosis, and most babies in the higher-risk group turn out to be perfectly healthy.

If screening comes back high risk — CVS at 11 to 14 weeks

Where a definite answer is needed early, your doctor may discuss chorionic villus sampling (CVS) — a diagnostic test on a small sample of placental tissue. It is offered, never assumed, and only after proper counselling about what the result would mean for your care.

Second trimester (weeks 14–27)

Anomaly / TIFFA scan — 18 to 22 weeks

If there is one scan not to miss, it is this one. The anomaly scan — also called TIFFA or the level-2 scan — is a careful, systematic examination of your baby from head to toe: the brain and skull, face and lips, spine, the four chambers of the heart and its outflow vessels, the stomach, kidneys and bladder, the abdominal wall, and the arms, legs, hands and feet. It also assesses the placenta, the cord and the amniotic fluid.

It takes time, it is done at a specific window when the organs are large enough to see but the baby still has room to be viewed, and it needs an experienced radiologist. And here is the honest part every parent deserves to hear: no scan can detect every condition. A detailed anomaly scan identifies a majority of significant structural problems, but some conditions are subtle, some develop later in pregnancy, and some cannot be seen on ultrasound at all. A normal report is genuinely reassuring — it is not a guarantee, and any centre that tells you otherwise is not being straight with you.

Quadruple marker — 14 to 20 weeks, if first-trimester screening was missed

If you did not have the NT scan and double marker in time, the quadruple marker blood test offers second-trimester screening instead. It is a fallback rather than a first choice — combined first-trimester screening is generally preferred where the timing allows.

Fetal echocardiography — 18 to 24 weeks, when advised

The anomaly scan already examines the heart. A dedicated fetal echocardiography is a deeper study, advised in specific situations — a family history of congenital heart disease, maternal diabetes, certain medications, an increased NT measurement, or something on the anomaly scan that needs a closer look.

Third trimester (weeks 28 to delivery)

Growth scan + colour Doppler — from about 28 to 32 weeks

The focus now shifts from structure to wellbeing. A growth scan with colour Doppler estimates your baby’s weight and checks it is growing along a healthy curve, measures the amniotic fluid, looks at the position of the placenta, and — through Doppler — studies blood flow in the umbilical cord and the baby’s vessels. That blood-flow information is what can reveal early, treatable problems long before anything feels wrong to you.

Later scans — 36 weeks onwards, as advised

Closer to delivery your doctor may advise another scan to check growth, the baby’s position, the fluid level and general wellbeing, which helps in planning the birth. In pregnancies with diabetes, high blood pressure, twins, a low-lying placenta or a growth concern, scans may be repeated more often — each one for a specific clinical reason.

What about a 3D/4D scan?

A 3D or 4D ultrasound is an optional addition, usually between 26 and 32 weeks, that shows your baby’s surface features and movements. It is lovely to have — and it is not a medical scan. It does not replace the anomaly scan or the growth scan, and it should never be presented to you as though it does.

Are all these scans safe?

Yes. Ultrasound uses sound waves, not radiation, and has been used in pregnancy for decades with an excellent safety record. The professional principle is prudent use: scans should be performed by trained personnel, for a clinical purpose, for a sensible duration — rather than repeatedly and casually. That is also the sensible answer to a question many parents ask: more scans are not automatically better care. The right number is the number your doctor has a reason to order.

What if I have missed a scan window?

First — do not panic, and do not blame yourself. Tell your obstetrician the dates honestly and they will adjust. Some windows can be substituted (first-trimester screening can be replaced by the quadruple marker), some can be done slightly late with a note about reduced accuracy, and some simply move to the next appropriate test. What matters is picking the schedule back up, not the missed date itself.

A legal point every parent in India should know

Under the PC-PNDT Act, determining or disclosing the sex of an unborn baby is illegal in India. No doctor, sonologist, laboratory or diagnostic centre may reveal it — at any scan, at any stage, however the question is put. Registered centres follow this without exception, and a facility that offers otherwise is committing a serious offence. Everything else about your scan is fully yours to discuss and understand.

Pregnancy scans at Edge Imaging & Diagnostics, West Delhi

Edge Imaging & Diagnostics is a NABH-accredited diagnostic centre in West Delhi where obstetric scans are performed and reported by experienced radiologists on high-resolution ultrasound, with the marker blood tests done in an in-house pathology lab. Having your dating, NT, anomaly, growth and Doppler scans at one centre means your measurements are compared consistently over time — which is exactly what makes a growth curve meaningful. We are fully PC-PNDT compliant, most reports are ready the same day, and our units in Paschim Vihar, Raghubir Nagar (Tagore Garden) and Moti Nagar serve families across Rajouri Garden, Punjabi Bagh, Janakpuri, Kirti Nagar and West Delhi. Indicative pricing for each scan type is in our ultrasound cost guide.

📩 Book your pregnancy scan on WhatsApp  |  Call 9555999960

Several of these scans measure the amniotic fluid around the baby. A report of “excess fluid” or polyhydramnios is usually mild and just re-checked; for what happens when it is severe, see amnioreduction and polyhydramnios treatment.

Frequently asked questions

How many ultrasound scans are done in pregnancy?

Most uncomplicated pregnancies involve about three to five scans — a dating scan, an NT scan at 11–13+6 weeks, an anomaly scan at 18–22 weeks, and one or more growth scans with Doppler in the third trimester. Additional scans are advised only when there is a specific medical reason.

Which scan is done in which month of pregnancy?

Roughly: dating scan in month 2, NT scan in month 3, anomaly (TIFFA) scan in months 5 to 6, and growth scans with Doppler from month 7 onwards. Your obstetrician sets the exact dates based on your individual pregnancy.

Which pregnancy scan is the most important?

Each has a distinct job, but the anomaly (TIFFA) scan at 18–22 weeks is the most detailed structural examination of your baby. The dating scan matters greatly too, because every later scan is timed from it.

Are ultrasound scans safe for the baby?

Yes. Ultrasound uses sound waves, not radiation, and has an excellent safety record in pregnancy. The accepted principle is that scans should be done by trained personnel for a clinical purpose and a sensible duration.

Can the anomaly scan detect every abnormality?

No. A detailed anomaly scan detects a majority of significant structural conditions, but not all — some are subtle, some appear later in pregnancy, and some cannot be seen on ultrasound. A normal scan is reassuring but is not a guarantee.

What happens if I miss a scan window?

Tell your obstetrician your dates honestly and they will adjust the plan. Some tests have alternatives — for example, the quadruple marker can replace missed first-trimester screening. Missing one window does not mean losing the rest of your care.

Do pregnancy scans tell the baby’s gender?

No. Under India’s PC-PNDT Act it is illegal to determine or disclose the sex of an unborn baby, and no registered centre or doctor will do so at any scan.

The bottom line

Pregnancy scans are not a random series of appointments — they are a sequence, each with a purpose and a window: confirm and date the pregnancy, screen early for chromosomal risk, examine the baby’s structure in detail at mid-pregnancy, then watch growth and blood flow as delivery approaches. Understand that sequence and the slips of paper stop being frightening and start making sense. Keep your obstetrician in charge of the schedule, have the scans done properly at an accredited centre, and let the rest of your pregnancy be about what it should be.

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Obstetric ultrasound at Edge Imaging & Diagnostics, West Delhi — a NABH-accredited diagnostic centre — is performed and reported by experienced radiologists in full compliance with the PC-PNDT Act. This article is general patient information only. It does not replace your obstetrician’s advice, and your scan schedule should always be decided by your treating doctor based on your individual pregnancy. Last updated: 2026.