Growth Scan in Pregnancy: How I Track Your Baby's Size and Blood Flow

Growth Scan with Doppler: What Each Part Adds

A growth scan answers one question: is the baby growing as expected? I measure the head, the abdomen and the thigh bone (femur). From these I estimate the baby's weight and plot it on a chart, so that I can follow the trend over several scans.

Doppler adds information about blood flow - in the umbilical cord, in an artery in the baby's brain and, sometimes, in a vein close to the heart. It helps me tell apart a baby who is healthy but small from one whose placenta is struggling. That decides how often we scan and when the baby should be born.

Growth and Doppler monitoring is a routine part of the high-risk pregnancy care I provide, so I do the scan myself and make the care plan in the same sitting. Neonatal support is on site at the hospital, and its staff cover labour and emergencies 24×7.

What I Measure at a Growth and Doppler Scan

• Head circumference, abdominal circumference and femur length - together they give the estimated fetal weight.
• Centile and trend - where the baby sits on the growth chart and how that has changed since the last scan.
• Amniotic fluid - the deepest pool (normally about 2–8 cm) or the amniotic fluid index.
• Umbilical artery Doppler - the resistance in the placenta.
• Middle cerebral artery Doppler and cerebroplacental ratio - blood flow to the baby's brain.
• Ductus venosus Doppler - in early, severe growth restriction.
• Uterine artery Doppler - the mother's side of the placenta.
• Placenta and presentation - where the placenta lies and which way the baby is lying in the third trimester.

Small Baby or Growth Restriction: Telling Them Apart

Small for gestational age (SGA) means the estimated weight is below the 10th centile. Many of these babies are healthy and simply small by build.

Fetal growth restriction (FGR) means the baby is not reaching its growth potential, usually because the placenta is not supplying enough. By the Delphi consensus, FGR is diagnosed when the baby is below the 3rd centile, or is small and has abnormal Doppler, or has dropped across centiles between scans.

FGR affects roughly 5–10% of pregnancies and is one of the more common causes of stillbirth that can be foreseen - which is why careful monitoring matters.

• Early-onset FGR (before 32 weeks) is usually more severe, with clear changes on Doppler.
• Late-onset FGR (after 32 weeks) is more common, shows milder Doppler changes and is easier to miss.

Who Is More Likely to Have a Baby With Growth Problems

• High blood pressure or pre-eclampsia, now or in a previous pregnancy.
• Diabetes from before pregnancy with blood-vessel disease, kidney disease, lupus or APLA.
• A previous baby who was small or stillborn.
• Smoking or chewing tobacco, including gutka and mishri.
• Moderate to severe anaemia, or a very low weight before pregnancy.
• Twins, especially monochorionic twins who share a placenta.
• Age over 40
• Low PAPP-A, or abnormal uterine artery Doppler, in early pregnancy.

Growth Scan Report: Reading the Doppler Values Vessel by Vessel

A growth scan report usually opens with the measurements (HC, AC, FL) and the estimated fetal weight with its centile. It then gives the amniotic fluid (deepest pool or AFI), the placenta and the baby's presentation. A "normal" report means the weight sits within the expected range for your weeks, and the trend since the last scan is steady. It also means the fluid is in range and the Doppler values are normal for gestation. The Doppler lines are the ones patients find hardest to read, so here is what each vessel tells me:

How Doppler Findings Shape Monitoring and the Timing of Birth

• Normal growth and Doppler: your routine care carries on
• SGA with normal Doppler: I recheck growth every 2 weeks with a Doppler in between; birth is often planned at 37–38 weeks.
• Abnormal umbilical artery Doppler: scans become more frequent - sometimes twice a week - together with CTG.
• Absent end-diastolic flow: birth is usually planned by about 34 weeks.
• Reversed flow: birth by about 30–32 weeks, or earlier if the ductus venosus or the CTG gets worse.

If birth before 34 weeks looks likely, I give steroid injections to help the baby's lungs mature. Before 32 weeks I also give magnesium sulphate to protect the baby's brain, and the neonatal team meets you beforehand.

For a baby who is small but otherwise well, the most common plan is induction at 37–38 weeks with continuous CTG during labour. With every growth scan, my aim is to time the birth well - neither too early nor too late.

Doppler Scan in Pregnancy: Is It Mandatory?

No - a Doppler scan in pregnancy is not a routine requirement for every woman. In a low-risk pregnancy with a baby growing normally, adding Doppler has not been shown to improve outcomes, so I do not ask for it by default.

It becomes important when there is a reason to look at how well the placenta is working:

• A baby measuring small, or growth slowing across scans.
• High blood pressure, pre-eclampsia, or diabetes with blood-vessel disease.
• APLA, lupus or kidney disease.
• A previous small baby or stillbirth.
• Monochorionic twins
• Low PAPP-A or raised uterine artery resistance in early pregnancy.
• Reduced fluid, or a change in the baby's movements.

In these situations the evidence is clearer: umbilical artery Doppler helps decide when closer monitoring or birth is needed. For you, Doppler simply adds a few minutes to the ultrasound - no needle, no injection and no special preparation.

Growth Scan in Which Week? Timing in the Last Three Months

Most growth scans fall between 28 and 36 weeks - the seventh to ninth months - because that is when growth problems linked to the placenta usually show up. When the risk is higher, for example after a previous growth-restricted baby, I start earlier, at about 24–28 weeks.

Growth itself is not re-measured more often than every two weeks. The measurements carry an error of their own, and a shorter gap can make the trend look worse or better than it really is. Doppler is different - when the placenta is under strain it may be repeated once or twice a week, with a CTG.

If your bump measures larger or smaller than expected at a routine visit, a growth scan is usually arranged within days rather than at a fixed week. Near term, a final scan may be timed for about 36 weeks to check size, fluid and the baby's position before the birth plan is confirmed.

Growth Scan in Pregnancy: Other Reasons I Ask for One

• When the baby seems large - for example in gestational diabetes, an abdominal circumference above the 95th centile tells me sugar control needs tightening.
• To assess too much fluid (polyhydramnios) or too little (oligohydramnios).
• To compare the two babies in a twin pregnancy.
• When the fundal height differs from the number of weeks by more than 2 cm.

For Indian women, I prefer growth charts suited to our population so that healthy babies are not wrongly labelled as small; INTERGROWTH-21st charts are commonly used.

On diet, I suggest protein (dal, paneer, curd, eggs, pulses), green leafy vegetables and iron-rich foods (ragi, dates, and jaggery in moderation). Please also take the iron and calcium tablets you have been prescribed. A diet like this can help keep anaemia under control and support the placenta, but it cannot reverse growth restriction once it has set in.

Growth Problems and Your Next Pregnancy

After FGR or early pre-eclampsia, the chance of it happening again is higher. For the next pregnancy I usually advise first-trimester screening, low-dose aspirin from 12 weeks where it is indicated, and growth scans from about 24–28 weeks.

Placental problems can also be an early signal about heart health later in life. So I advise checking your blood pressure, weight and sugar from time to time in the years ahead.

How I Run Growth Surveillance at Divine Women's Hospital

• I perform the growth and Doppler scans myself and plot each one against all your earlier scans on a single chart.
• If the Doppler is abnormal, a CTG can be done at the same visit.
• If pre-eclampsia is a concern, I add blood pressure, urine and blood tests.
• From about 28 weeks, I ask you to keep track of the baby's movements. There is no fixed kick count - what matters is your baby's usual pattern.
• If the movements reduce, come in the same day, at any hour.
• When an early birth is likely, planning includes a meeting with the neonatal team, the steroid and magnesium plan, and a shared decision on the timing and mode of birth.

Growth Scan Price in Ahmedabad: Why There Is No Single Figure

The charge for a growth scan depends on what each visit has to include, so I do not print one figure here. Current charges are available from the hospital on request.

What makes the difference:

• Growth only, or growth with Doppler - and which vessels are studied (umbilical, middle cerebral, ductus venosus, uterine).
• One baby or twins - each twin is measured and assessed separately.
• A CTG at the same visit - added when the Doppler is abnormal or movements have changed.
• How many scans you need - a single reassurance scan differs from a series every two weeks, or Doppler twice a week.
• Other tests - blood pressure, urine and blood tests when pre-eclampsia is a concern.

If you have a prescription from another doctor, bring it when you enquire; it shows which parts of the scan have been asked for.

Your Growth Scan Visit, Step by Step

1. Measurementsthe head, abdomen and femur; the estimated weight goes onto your personal growth chart.
2. Fluid and placentaI check the amniotic fluid, where the placenta lies and the baby's presentation.
3. Dopplerthe umbilical and brain vessels, and the uterine and venous vessels where needed.
4. InterpretationI compare the findings with your previous scans and add a CTG if needed.
5. Plan until the next scanyou leave with the date of the next scan, the warning signs to watch for and the likely birth plan.

When to Ask for a Growth Scan

• Your bump measures smaller or larger than expected for your dates.
• You have high blood pressure, pre-eclampsia, diabetes, kidney disease or APLA.
• A previous baby was small, stillborn, or born early because of poor growth.
• An earlier scan showed low fluid, a small baby or an abnormal Doppler.
• You are expecting twins.
• Your NT scan showed low PAPP-A or abnormal uterine artery Doppler.

Myths About Small and Big Babies

Questions Patients Often Ask Me About Growth and Doppler Scans