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See your baby's heartbeat, confirm your due date, and check early development. The most reassuring and emotional moment of early pregnancy. From 8–14 weeks. £235 all-inclusive.
Secure online booking · Immediate confirmation · No hidden fees
A dating ultrasound-scan is the first detailed assessment of your pregnancy, typically performed between 8 and 14 weeks of gestation. It is the most accurate method available for establishing your estimated due date (EDD) and confirming that the pregnancy is developing as expected.
The scan uses crown-rump length (CRL) measurement — the distance from the top of your baby's head to the base of the spine — to calculate gestational age. CRL measurement at this stage is accurate to within 5–7 days, making it significantly more reliable than a date calculated from your last menstrual period (LMP), particularly if your cycles are irregular.
At Sonoworld, the dating ultrasound-scan is performed by HCPC-registered sonographers at our CQC-registered clinic at 29 Weymouth Street, Marylebone. No GP referral is required. Same-day appointments are available for urgent cases.
The NHS offers a routine 12-week scan, but many expectant mothers choose a private dating scan earlier — from 8 weeks — for reassurance, especially after a previous pregnancy loss, IVF, or fertility treatment. A private scan also means a shorter wait, a longer appointment, and printed photos to take home on the day.
| Price | £235 all-inclusive |
| Duration | 20–30 minutes |
| Gestation | 8–14 weeks |
| Approach | Transabdominal (transvaginal if needed) |
| Bladder prep | Comfortably full bladder recommended |
| Photos | Printed photos included |
| Report | Verbal findings on the day; written on request |
| Partner | Welcome to attend |
| GP referral | Not required |
The dating ultrasound-scan provides a systematic assessment of six key areas. Each finding is explained to you in real time by your sonographer as the scan progresses.
| What Is Assessed | What the Sonographer Looks For | Why It Matters |
|---|---|---|
| Gestational sac | Size, shape, and position within the uterus | Confirms intrauterine pregnancy; rules out ectopic implantation |
| Yolk sac | Presence and appearance | Supports early fetal nutrition; absence at >5.5 weeks may indicate a non-viable pregnancy |
| Fetal pole & CRL | Crown-rump length measured in millimetres | Most accurate method for gestational age dating; calculates EDD to within 5–7 days |
| Fetal heartbeat | Cardiac activity confirmed; heart rate measured in bpm | Confirms viability; normal range 110–175 bpm at 8–14 weeks |
| Number of fetuses | Single or multiple gestation; chorionicity if twins | Identifies twin or higher-order pregnancies; determines placental sharing |
| Uterus & adnexa | Uterine structure, ovaries, and adnexal region | Identifies fibroids, ovarian cysts, or other incidental findings |
CRL is measured from the top of the fetal head (crown) to the bottom of the buttocks (rump). At 8 weeks, the CRL is approximately 16 mm; at 12 weeks, it is around 60 mm. The measurement is plotted against established reference charts (NICE CG62 / ISUOG guidelines) to calculate gestational age and EDD. CRL dating is more accurate than LMP-based dating in women with irregular cycles, recent hormonal contraception use, or uncertain last period dates.
CRL measurement is most accurate between 8 and 13 weeks 6 days. After 14 weeks, head circumference (HC) and biparietal diameter (BPD) measurements are used instead. If you are unsure of your gestation, a scan between 10 and 12 weeks gives the clearest images and most reliable measurements.
Many expectant mothers choose a private dating ultrasound-scan for reasons that go beyond what the NHS 12-week scan can offer in terms of timing and access.
Early reassurance before the NHS 12-week scan. Seeing a heartbeat and getting an accurate due date at 8–10 weeks removes weeks of uncertainty and anxiety.
After a miscarriage or stillbirth, early viability confirmation provides immediate reassurance. A heartbeat seen at 8 weeks significantly reduces the statistical risk of further loss.
IVF pregnancies require early dating as the LMP is not a reliable indicator of gestational age. The scan also confirms the number of embryos that have implanted and identifies chorionicity in twin pregnancies.
Irregular cycles, recent hormonal contraception, or an unknown LMP make period-based dating unreliable. CRL measurement provides an accurate EDD regardless of cycle length, which is important for maternity leave planning and NHS booking-in appointments.
Light bleeding (spotting) in early pregnancy is common but always warrants prompt assessment. A dating scan confirms the pregnancy is intrauterine, the heartbeat is present, and rules out ectopic implantation. Same-day appointments are available.
Many couples simply cannot wait until the NHS 12-week scan. A private dating scan at 8–10 weeks gives you your first look at your baby, printed photos to share with family, and the reassurance to start telling people your news.
Seek urgent assessment if you experience
Heavy vaginal bleeding, severe one-sided pelvic pain, shoulder-tip pain, or dizziness in early pregnancy. These may indicate an ectopic pregnancy, which requires immediate medical attention. Call 999 or attend your nearest A&E. Same-day appointments are also available at Sonoworld — call 020 3633 4902.
Drink 3–4 glasses of water 1 hour before your appointment. A comfortably full bladder lifts the uterus into a better position for transabdominal imaging.
Wear a two-piece outfit — you will need to lower your waistband slightly to expose the lower abdomen. Loose-fitting trousers or a skirt are ideal.
Bring the date of your last menstrual period if known. If you have had a previous scan, bring the report. For IVF pregnancies, bring your embryo transfer date.
Arrive 10 minutes before your appointment time. Bring your booking confirmation email. Your partner or a support person is welcome to attend.
If the transabdominal images are unclear — which can happen at earlier gestations or with a retroverted uterus — your sonographer may offer a transvaginal scan. This uses a slim probe and requires an empty bladder. The procedure is performed with your full consent and can be stopped at any time. It provides a significantly clearer image at 8–10 weeks.
From arrival to leaving with your photos — a step-by-step guide to your appointment.
Arrive at 29 Weymouth Street 10 minutes before your appointment. The reception team will greet you. Your partner is welcome in the waiting area and scan room.
Your HCPC-registered sonographer takes a brief history: LMP or embryo transfer date, any symptoms (bleeding, pain), previous pregnancy history, and whether this is a natural or assisted conception.
You lie comfortably on the examination couch. Warm gel is applied to your lower abdomen. The sonographer systematically assesses the uterus, measures CRL, checks the heartbeat, and confirms the number of fetuses. Everything is narrated to you on screen in real time.
Findings are discussed straight away. You receive your estimated due date (EDD) based on CRL measurement, printed photos, and a verbal explanation of everything seen. Questions are encouraged throughout.
You receive guidance on your next scan — the NHS 12-week anomaly scan, a gender scan from 16 weeks, or a follow-up if any concerns were identified. A written report is available on request for your GP or midwife.
One price. Everything included. No hidden fees, no additional charges for photos, and no surprise extras.
Private health insurance accepted. Contact us to confirm coverage before booking.
4.9 out of 5 · 342 verified reviews for the dating scan
"Seeing my baby's heartbeat for the first time was the most emotional moment of my life. I cried happy tears. The sonographer was so lovely and patient, explaining everything on the screen. My partner and I left with printed photos and so much reassurance."
"After two previous miscarriages, I was so anxious in this pregnancy. Seeing that strong heartbeat at 9 weeks was the biggest relief. The sonographer was so understanding of my anxiety and took extra time to reassure me. I am now 20 weeks and baby is doing great."
"IVF pregnancy and we could not wait for the 12-week NHS scan. Booked privately at 10 weeks and discovered we are having twins! The sonographer showed us both heartbeats and explained they have separate placentas. My husband and I were in happy shock."
"I had some light bleeding at 11 weeks and was terrified. Sonoworld got me in the same day. Seeing my baby's heartbeat strong and healthy was the most reassuring thing ever. The staff were so kind and supportive. Cannot recommend enough for worried mums-to-be."
"I had irregular cycles and no idea when I conceived. The dating scan gave me an accurate due date which was two weeks different from my estimate. Super important for planning maternity leave. Quick, professional, and the sonographer made me feel so comfortable."
CQC-registered private diagnostic ultrasound clinic in central London. A short walk from Regent Street, Oxford Circus, and Regent's Park tube station.
29 Weymouth Street, Marylebone, London W1G 7DB
Nearest tube: Regent's Park (Bakerloo) · Great Portland Street (Circle / Metropolitan / Hammersmith & City)
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