Private Dating Scan in London

When should I have my dating scan?

Between 10 and 15 weeks, with 11 to 13 weeks the sweet spot for the most accurate dating. Many parents know it as the 12-week scan. If you are earlier than 10 weeks, an early pregnancy scan is the right appointment; if you are past 15 weeks, the gender and wellbeing scan or the anomaly scan is the next step. Unsure of your dates? Tell us when you book and we will guide you to the right scan.

How accurate is a dating scan?

Very: between 10 and 13 weeks the crown-rump measurement dates a pregnancy to within about five days, which is why both NHS and private clinics use it as the gold standard for setting a due date. Accuracy falls slightly after 14 weeks as babies start to grow at different rates, so earlier is better if dating is your main reason for coming.

Can a dating scan change my due date?

Yes, and it often does. If the scan date differs from the date worked out from your last period, the scan date is usually adopted, because ovulation and conception vary so much from person to person. The exception is IVF: if your embryo transfer date is known, that date stays, and the scan simply confirms your baby is growing as expected.

Can I just use my last period to work out my due date?

You can estimate it: add 40 weeks to the first day of your last period. But that assumes a regular 28-day cycle with ovulation on day 14, which is not true for many people, and it fails completely if your cycles are irregular, you were breastfeeding or you conceived on contraception. A dating scan measures the baby directly, so it does not depend on any of that.

Can a dating scan detect twins?

Yes. By 10 weeks a twin pregnancy is clearly visible, and your sonographer will also record the chorionicity: whether the twins share a placenta or each have their own. That single detail shapes the rest of your care, because twins sharing a placenta are monitored more closely, so it is one of the most important things a dating scan tells you.

Does a dating scan check for abnormalities?

It includes an early anatomy check for the small number of major problems that can already be seen at this stage, such as abnormalities of the skull, abdominal wall or limbs. It is not the detailed anomaly scan, which comes at 18 to 24 weeks, and it does not screen for chromosomal conditions such as Down’s syndrome: for that, NIPT can be added to the same visit from 10 weeks.

Does the dating scan include a nuchal translucency (NT) measurement?

The nuchal translucency measurement is the ultrasound part of the NHS combined screening test at 11 to 14 weeks, where it is interpreted together with blood markers to give a chance result for Down’s syndrome. Our dating scan is focused on dating, viability, the number of babies and the early anatomy. For chromosomal screening we recommend NIPT, which reads your baby’s DNA from a blood sample and detects more than 99% of cases, far more accurately than the combined test; it can be added to the same appointment.

Can a dating scan tell me the sex of my baby?

Not reliably. The external genitals are only just forming at 12 weeks and even an experienced sonographer cannot call it with confidence, so we do not guess. From 16 weeks the gender and wellbeing scan can tell you, and NIPT can report the sex from 10 weeks if you would like to know early.

Do I need a full bladder for a dating scan?

No. The scan is performed transvaginally as standard, so your bladder should be empty: please use the toilet just before you go in. Only if you ask for the scan through the tummy do you need a full bladder, drinking a litre of water 45 to 60 minutes before.

Will I need an internal scan at my dating scan?

Yes, as standard: a transvaginal scan gives the clearest, most accurate measurement for dating. It is gentle, not painful, takes a few minutes and is only done with your consent. If you would prefer the scan through your tummy, tell us when you book and arrive with a full bladder.

How long does a dating scan take?

Around 20 minutes. That includes a short chat about your dates, the measurements, a count of the number of babies, the heartbeat, the early anatomy look, and time for your sonographer to explain everything on screen while you watch. Your scan images and the written report are ready before you leave.

What if my baby is measuring small or large for my dates?

In most cases it simply means your dates were slightly out, and the scan date becomes your new due date. If the heartbeat and development look as expected, a difference of a few days is nothing to worry about. If your sonographer sees anything that genuinely needs attention, they explain it in the room and arrange the right next step, including a consultant review the same day.

How much does a private dating scan cost in London?

£160 at Harley Street Ultrasound, all fees inclusive: the scan, your sonographer’s time, your scan images and your written report, with nothing added on the day. You can book online without a referral, and the same-day and next-day appointments mean you are not waiting weeks for your first look at your baby.

Can I have a dating scan on the NHS as well?

Yes. The NHS offers a dating scan between 10 and 14 weeks, and a private scan with us does not replace it or affect it. Many parents book privately for an earlier appointment, a longer and more relaxed scan with a partner and children welcome, or extra reassurance between NHS visits. If anything needs attention, we write to your midwife or GP.

What if something needs a closer look?

Your sonographer tells you in the room, gently and in plain English, and explains exactly what it means. You are never sent home to wait for a letter. Most of the time a finding simply needs a repeat scan in a week or two, or a measurement checked again at the next routine scan.

If something genuinely needs attention, a consultant review is available the same day, and we arrange the next step for you: a referral to a fetal medicine specialist or early pregnancy unit, with your report and images, through our hospital partners. You will not be left alone with a worry.

Do I need a referral?

No. Harley Street Ultrasound is a private clinic, so you can book a dating scan in London directly online or by phone, with no GP or midwife letter and no waiting list. Same-day and next-day appointments are usually available, and we are at 99 Harley Street, a short walk from Regent’s Park and Oxford Circus stations.

The price is published before you book: £160, all fees inclusive, covering the scan, your sonographer’s time, your scan images and your written report. Pregnancy scans are usually self-pay; if you are insured, check whether your policy covers pregnancy scanning before you book.

How soon will I have the written report?

The same day. You will already know what was seen, because your sonographer explains everything on screen as the scan happens, and your written report is published to your secure patient portal with your images before the day ends, ready to share with your midwife, GP or consultant.

Your scan images are on your secure portal the same day.

Is ultrasound safe for my baby?

Yes. Ultrasound uses sound waves, not radiation, and has been used in pregnancy for more than fifty years with no confirmed harmful effects on babies. Our sonographers keep scan times to what is clinically needed and use hospital-grade equipment, so a scan can be repeated safely whenever it is useful.

Can I still have my NHS scans afterwards?

Yes, completely. A private scan with us never affects your NHS maternity care: keep every NHS appointment as planned. Many parents book with us for extra reassurance between NHS scans, or for a scan the NHS does not routinely offer. If anything needs attention, your sonographer writes to your midwife or GP so that you re-enter the NHS pathway with the findings already in hand.