By Yianni Kiromitis — PgC Medical Ultrasound, BSc (Hons). HCPC-registered Sonographer (RA38415)

Medically reviewed by Yianni Kiromitis, HCPC-registered Sonographer (RA38415) — 15 July 2026

Last reviewed: 15 July 2026

An eight-week pregnancy scan checks that a pregnancy is developing well: it usually shows an embryo measuring around 14 to 20 millimetres with a clearly visible heartbeat. It is one of the most reassuring early scans we offer, because by eight weeks there is usually enough to see to give a clear picture of how the pregnancy is progressing.

What the scan shows at 8 weeks

At eight weeks, the embryo measures roughly 14 to 20 millimetres from crown to rump — about the size of a raspberry. The heartbeat is usually clearly visible, flickering rapidly on the screen. The head is large in proportion to the body, and small limb buds are beginning to form. The gestational sac and yolk sac are still visible, though the yolk sac will gradually disappear over the coming weeks as the placenta takes over.

During the scan, the sonographer will confirm the pregnancy is viable and located inside the uterus, measure the crown-rump length (CRL) to give an accurate estimated due date, check the number of babies, and note the heart rate.

Abdominal or internal scan?

At eight weeks, it is often possible to get a reasonable view using an abdominal scan (over the tummy), provided you arrive with a full bladder. However, an internal (transvaginal) scan gives a much clearer, more detailed image at this stage. If the abdominal view is not clear enough, the sonographer will recommend an internal scan. Both are safe and comfortable.

What an 8-week scan cannot tell you

It is too early to determine the baby's sex at eight weeks. The genital structures are not yet developed enough to distinguish. It is also too early for the nuchal translucency (NT) scan, which screens for Down's syndrome — that must be performed between 11 weeks and 13 weeks 6 days.

Preparing for your scan

If you are having an abdominal scan, drink a pint of water about an hour before your appointment and do not empty your bladder. A full bladder lifts the uterus out of the pelvis and gives a better view. If you are having an internal scan, an empty bladder is more comfortable. You can use our scan timing calculator to check exactly when you will be eight weeks.

From our practice

The eight-week scan is often the first time a pregnancy feels real. Seeing a clearly formed embryo with a strong, fast heartbeat — and being able to measure it and calculate a due date — transforms the experience from a positive test into a pregnancy. I love this appointment. Patients often come in anxious and leave smiling. If you would like this kind of reassurance, you can book an early pregnancy scan with us. You might also find our article on the 9-week pregnancy scan helpful for what to expect next.