First Trimester Scans: Complete Guide
The first trimester brings your first real glimpses of your baby, and it can be confusing to work out which scans are routine NHS care and which are optional extras you pay for privately. Here's a clear rundown of what's on offer, when it happens, and what each scan is actually looking for.
NHS scans in the first trimester
On the NHS, most people in England, Scotland, Wales and Northern Ireland are offered one scan during the first trimester: the 12-week scan, also called the dating scan, usually carried out somewhere between 11 and 14 weeks.
This scan does three main jobs:
- Dating your pregnancy — measuring the baby from crown to rump to confirm how many weeks pregnant you are and set your official due date, which may shift slightly from a date based on your last period.
- Checking for one baby or more — confirming whether you're expecting a single baby, twins, or more.
- Nuchal translucency (NT) measurement — as part of the combined screening test, the sonographer measures the fluid at the back of baby's neck, which (combined with a blood test and your age) gives you a personalised chance figure for conditions like Down's syndrome, Edwards' syndrome and Patau's syndrome. This screening is optional — you can decline it and still have the dating scan.
You'll usually need a full bladder for this scan, as it helps get a clearer abdominal ultrasound picture. Appointments typically last 20–30 minutes, and most units are happy for a partner or support person to come with you — it's worth checking your hospital's specific visitor policy in advance.
Private early scans
Because the NHS dating scan doesn't happen until 11 weeks or later, many people choose to book a private early scan sooner, purely for reassurance. These aren't diagnostic and don't replace your NHS care — they're an optional extra.
- Viability scan (around 6–8 weeks) — checks for a heartbeat and confirms the pregnancy is developing inside the womb. Very early scans may need to be transvaginal, as the baby is too small to see clearly through the abdomen yet.
- Early reassurance scan (around 7–9 weeks) — often booked by people who've had previous miscarriage or after fertility treatment, to confirm things are progressing as expected.
- Gender scans via nub theory (around 12–13 weeks) — some private clinics offer an early guess at baby's sex based on the angle of the genital tubercle, though this is far less reliable than a formal anomaly scan later on and should be treated as a bit of fun rather than a confirmed result.
Private scans are widely available on the high street and in hospitals with private wings; prices and what's included (photos, video, extra checks) vary, so it's worth asking exactly what you'll get before booking.
What to expect at your scan
Whether NHS or private, the process is broadly similar:
- Gel is applied to your abdomen and a handheld probe (transducer) is moved over the area to create the ultrasound image. If it's very early in pregnancy, a transvaginal scan may be used instead for a clearer view.
- The sonographer will point out what they can see on the screen, though they're generally not able to give you full results or a definitive diagnosis during the scan itself — findings usually get confirmed afterwards.
- Most scans are painless, though a full bladder for an early abdominal scan can be uncomfortable.
- You'll typically be offered printed photos for a small fee, and some units allow you to record video on your phone — ask beforehand.
Getting ready
- Check your appointment letter for whether you need a full bladder, and drink water accordingly beforehand.
- Bring your maternity notes or booking paperwork if you have them.
- Wear something that makes it easy to access your lower abdomen.
- Write down any questions in advance — appointments can move quickly and it's easy to forget what you wanted to ask.
Frequently Asked Questions
When is the first NHS scan?
The first routine NHS scan is the 12-week (dating) scan, offered between 11 and 14 weeks of pregnancy. It confirms your due date, checks how many babies you're carrying, and includes the optional NT screening measurement. If you're worried before this point, contact your midwife or GP — an earlier scan can sometimes be arranged for medical reasons.
Can I have a private scan before 12 weeks?
Yes, private clinics widely offer viability and early reassurance scans from around 6 weeks onwards, usually for a fee. These are for peace of mind rather than routine screening and don't replace your NHS dating scan or antenatal care. If a private scan raises any concerns, contact your midwife or GP promptly so it can be followed up through the NHS.
Do I need a full bladder for a first trimester scan?
Often yes, particularly for very early abdominal scans, as a full bladder pushes the womb into a better position for imaging. Your appointment letter should specify what's needed — if it doesn't say, it's sensible to have a comfortably full bladder just in case, since a transvaginal scan can be used instead if required.
This article is for informational purposes only and does not constitute medical advice. Always consult your midwife, GP, or another qualified healthcare professional about your individual pregnancy.
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