28 Week Scan
The third trimester gets underway and the 4D HD Live bonding window hits its stride. Baby's face has filled out, the eyes can blink, there's still generous room to move, and our Gosforth scan room is set up so partners, grandparents and older siblings can all share the screen.
Quick Answer
At 28 weeks, baby is roughly 38cm from head to heel and weighs in around 1kg. The face has filled out with subcutaneous fat to give it that soft, recognisable look, the eyes can finally open and blink, the brain is developing at pace, and the lungs are rehearsing breathing motions. This is the sweet spot of the 24–34 week 4D HD Live window: baby is plump enough for photorealistic facial features but not yet so cramped that finding a clear view becomes a challenge. At our Gosforth clinic the 4D Baby Scan is £78 and the premium Luxury 4D package is £125.
What's Happening at 28 Weeks
Twenty-eight weeks officially marks the start of the third trimester, and it's a developmental turning point. Your baby is roughly aubergine-sized now, around 38 centimetres head to heel and weighing in at about a kilogram. The big structural building work of the first two trimesters is essentially behind us. From here, the focus shifts to growth, lung maturation, and the deep brain development that will continue rolling on for years after birth.
This is also the week the eyes open for the first time. Up until 28 weeks the eyelids have been fused shut to protect the developing retinas. Now they're physically capable of opening and closing, and baby will spend much of the third trimester practising, blinking, focusing on the dim light that filters through your abdominal wall, even reacting to a torch held against the bump. The lungs are producing surfactant, the substance that allows alveoli to inflate and deflate properly once baby is breathing air, and practice-breathing motions are well under way despite there being no air to draw in yet.
Externally, baby has rounded out. Where 20-week babies looked lean and slightly bony, 28-week babies are soft, plump and recognisable; there's enough fat under the skin to give the face that cherubic appearance parents tend to picture. The brain is developing folds and grooves quickly, and on a 4D HD Live bonding scan the hair on the head is now often visible. By this point most mums are feeling strong, regular movement: kicks, stretches, hiccups, the unmistakable rhythm of a sleep-wake cycle starting to hold.
Why 28 Weeks Is the 4D Sweet Spot
A good 4D HD Live image relies on three things falling into place at once: subcutaneous fat (so the rendered face looks soft and recognisable rather than gaunt), generous amniotic fluid (so there's a clear acoustic window between probe and face), and enough room to manoeuvre (so baby's face isn't pinned against the placenta or buried in the spine). All three peak somewhere in the 24–34 week stretch, and 28 weeks lands right in the middle.
Try too early, say 22 or 23 weeks, and the fat layer hasn't built up yet, so the rendering reads as bony. The technology works, it just doesn't deliver the image parents are picturing. Try too late, 35 or 36 weeks, and the fat is there in spades but baby is now so large that fluid volume drops and finding a face-up angle becomes hard work. Plenty of third-trimester babies spend that final stretch face-against-the-placenta or with hands and feet permanently arranged in front of their features.
If you can only book one 4D appointment, 28 weeks is the gestation we'd point you towards. If you want maximum flexibility, booking with the understanding that you can come back within the 24–34 week window is the better approach; and our policy is straightforward: we don't charge twice when baby's position is what stopped us getting a clear image the first time. For the standard 30-minute experience, the 4D Baby Scan is the right choice; for an extended 45-minute keepsake package the premium Luxury 4D Baby Scan is the upgrade.
Scan Packages for Week 28
4D Baby Scan
24–34 weeks
30-minute 4D HD Live appointment. Photos, digital images, USB and written report included.
View package →Luxury 4D Baby Scan
24–34 weeks
Extended 45-minute scan with the full keepsake package: multiple prints, USB with session recording, premium photo formats.
View package →Growth & Presentation Scan
From 24 weeks
Detailed clinical scan with full growth measurements, baby's position, fluid level, placenta location, the 2D late-pregnancy reassurance option alongside (or instead of) a 4D scan.
View package →Book Your 28 Week 4D Scan
The strongest single window for 4D HD Live bonding imagery. CQC-regulated, experienced and registered sonographers using GE Voluson equipment, two years on Bakers Yard, part of the award-winning Numi Scan group.