Precise measurements of your baby's head, abdomen, and femur to calculate estimated weight and growth percentile. Expert assessment from 28 weeks, with same-day appointments available.
HCPC-registered sonographers · Detailed written report included · Printed photos to take home
A growth ultrasound-scan provides precise measurements of your baby's size and development in the third trimester. Using standardised growth charts, your sonographer can tell you which percentile your baby is tracking and whether growth is progressing normally.
Three key parameters are measured β head circumference (HC), abdominal circumference (AC), and femur length (FL) β to calculate your baby's estimated fetal weight (EFW). This identifies babies who are smaller or larger than expected for their gestational age, allowing for appropriate monitoring and delivery planning.
Whether you have risk factors such as gestational diabetes or high BMI, your midwife has concerns about fundal height, or you simply want reassurance that your baby is thriving, a growth scan provides expert assessment with a detailed written report to share with your healthcare team.
| Best gestation | 28–40 weeks (third trimester) |
| Appointment length | 20–30 minutes |
| Preparation | No special preparation needed |
| Approach | Transabdominal (gel on abdomen) |
| Report | Detailed written report included |
| Photos | Printed photos to take home |
| Partners | Welcome in the scan room |
| Price | £164 all-inclusive |
The NHS 20-week anomaly scan checks for structural abnormalities. A growth scan is a separate third-trimester assessment focused on measuring your baby's size, weight, and wellbeing. The NHS does not routinely offer growth scans to all pregnancies β they are recommended for specific risk factors or when your midwife has concerns about fundal height.
Every growth scan includes nine components. Together, they build a complete picture of your baby's development, growth velocity, and placental function.
Measured around the widest point of your baby's head to assess brain growth and overall development. HC is plotted against gestational age on standardised growth charts.
The most sensitive indicator of growth restriction or macrosomia. AC reflects liver size and nutritional status, making it the single most important measurement in a growth scan.
Measurement of your baby's thigh bone assesses skeletal growth and contributes to the estimated weight calculation alongside HC and AC.
Calculated from HC, AC, and FL using validated Hadlock formulae. EFW is accurate to within 10–15% of actual birth weight and is the primary output of a growth scan.
Your baby's measurements are plotted on customised growth charts (INTERGROWTH-21st or Fetal Medicine Foundation). A percentile between the 10th and 90th is considered normal.
Low fluid (oligohydramnios) or high fluid (polyhydramnios) can indicate placental insufficiency, fetal anomaly, or gestational diabetes. Fluid assessment is included in every growth scan.
Position, appearance, and grade of the placenta are checked to confirm it is functioning correctly. Placenta praevia (low-lying placenta) is also assessed if relevant.
If growth restriction is suspected, Doppler ultrasound assesses blood flow through the umbilical artery and middle cerebral artery. This is included at no extra charge when clinically indicated.
A comprehensive written report with all measurements, percentiles, fluid assessment, placental findings, and clinical recommendations β ready to share with your midwife or obstetrician.
| Percentile | Classification | What it means |
|---|---|---|
| Below 3rd | Severely small for gestational age | Referral to fetal medicine consultant recommended |
| 3rd–10th | Small for gestational age (SGA) | Closer monitoring; serial growth scans advised |
| 10th–90th | Normal range | Baby growing appropriately for gestational age |
| 90th–97th | Large for gestational age (LGA) | Monitor for macrosomia; assess for gestational diabetes |
| Above 97th | Severely large for gestational age | Delivery planning discussion with obstetrician advised |
A growth scan is especially valuable when you have risk factors or your midwife has concerns. Many women also choose to book for reassurance alone β and that is a perfectly valid reason.
Regular growth scans monitor for macrosomia (large baby) and guide delivery planning. NICE guidelines recommend serial growth scans from 28 weeks if gestational diabetes is diagnosed.
If your midwife's fundal height measurement is more than 3 cm above or below the expected range for your gestation, a growth scan provides the precise measurements needed to assess growth properly.
A history of intrauterine growth restriction (IUGR) or macrosomia increases the risk of recurrence. Serial growth scans from 28 weeks provide early identification and appropriate management.
Maternal BMI below 18.5 or above 30 can affect fetal growth patterns. Fundal height measurement is also less reliable at extremes of BMI, making ultrasound assessment particularly valuable.
A reduction in your baby's movements from 28 weeks warrants assessment. A growth and wellbeing scan checks estimated weight, fluid levels, and placental function alongside a movement pattern review.
Many parents book a growth scan simply to see their baby and confirm that growth is on track. Knowing your baby's estimated weight and percentile in the third trimester provides genuine reassurance.
Significantly reduced or absent fetal movements · Severe abdominal pain · Heavy vaginal bleeding · Signs of pre-eclampsia (severe headache, visual disturbance, sudden swelling). Contact your midwife, maternity triage, or call 999 immediately. Do not wait for a private scan appointment.
A growth scan is performed transabdominally (gel on your abdomen). Unlike an early pregnancy scan, you do not need a full bladder. You can eat and drink normally before your appointment.
If you have risk factors, serial growth scans every 2–4 weeks provide a growth trajectory rather than a single snapshot. A single measurement cannot reliably distinguish a constitutionally small baby from one with growth restriction β the trend over time is what matters.
| Indication | Suggested timing |
|---|---|
| Gestational diabetes | 28, 32, 36 weeks |
| Previous IUGR | 28, 32, 36 weeks |
| Fundal height concern | At concern, repeat in 2–4 weeks |
| Reassurance only | 32–36 weeks |
Choose your appointment time at our booking page or call 020 3633 4902. Same-day and next-day slots are often available.
29 Weymouth Street is easily accessible from Regent's Park tube (Bakerloo) and Great Portland Street (Circle / Metropolitan). Your partner is very welcome to join you.
Your HCPC-registered sonographer takes a brief history β your gestation, any risk factors, and the reason for your scan β before beginning the examination.
Warm gel is applied to your abdomen. Your sonographer takes precise HC, AC, and FL measurements, assesses amniotic fluid and placenta, and performs Doppler if clinically indicated. You watch on the screen throughout.
Your sonographer calculates the estimated weight, explains which percentile your baby is tracking, and discusses what the findings mean for your pregnancy and any recommended next steps.
You receive printed ultrasound photos and a comprehensive written growth report with all measurements, percentiles, and clinical recommendations to share with your midwife or obstetrician.
Many private health insurance policies cover growth scans when medically indicated. Contact your insurer before booking to confirm coverage. Self-pay patients pay £164 at the time of booking β no additional fees apply.
4.9 out of 5 β β β β β · Based on 487 verified reviews
"I have gestational diabetes so was worried about my baby's size. Had a growth scan at 32 weeks and another at 36 weeks. The measurements were so reassuring and the sonographer explained everything clearly. Baby was tracking perfectly on the 60th percentile. Highly recommend for anyone with GD."
"My midwife said my bump was measuring small so referred me for a growth scan. The sonographer was wonderful β she took her time with all the measurements and showed me baby was actually growing beautifully on the 45th percentile. Such a relief. The detailed report put everyone's mind at ease."
"Had my first baby at 8lbs 12oz so wanted to monitor this one's growth. Growth scans at 28, 32, and 36 weeks showed baby tracking on the 85th percentile but not too big. Really helpful for planning my delivery. Professional service and same-day appointments available."
CQC-registered private diagnostic ultrasound clinic in central London. A short walk from Regent's Park, Great Portland Street, and Oxford Circus tube stations.
29 Weymouth Street, Marylebone, London W1G 7DB
Nearest tube: Regent's Park (Bakerloo) · Great Portland Street (Circle / Metropolitan / Hammersmith & City)