The 7-week ultrasound: what you will see

What is visible

A gestational sac, a yolk sac, and a fetal pole measuring roughly 8 to 13 mm — about the size of a blueberry.

A heartbeat, usually clearly seen by now, typically between about 120 and 160 beats per minute. Hearing or seeing it at this stage is meaningful: it substantially lowers the statistical risk of miscarriage from that point.

Not yet visible: recognisable limbs, facial features, or anything that could indicate sex — which is in any case illegal to determine or disclose in India.

This is usually a transvaginal scan, because at seven weeks it gives a far clearer picture than an abdominal one.

What it is for

Confirming the pregnancy is inside the uterus, which rules out an ectopic pregnancy — the most important thing an early scan does.

Confirming a heartbeat and the number of babies.

Dating: the crown-rump length at this stage dates the pregnancy within a few days, which is more accurate than any later measurement.

And checking the ovaries and uterus — fibroids, cysts and a subchorionic haematoma are all things that may be noted.

If the scan is uncertain

A scan at seven weeks by dates may show less if ovulation was later than assumed. A repeat in one to two weeks is standard, and it is not a diagnosis of anything.

Terms you may hear: 'no cardiac activity seen, repeat scan advised' means exactly that and is not yet a conclusion. hCG blood levels, measured twice 48 hours apart, are often used alongside.

This waiting period is genuinely hard. Ask for the repeat date before you leave, and see our guide on first-trimester anxiety.

When to see a doctor

Go to hospital immediately for heavy bleeding, severe or one-sided abdominal pain, fainting or dizziness, shoulder-tip pain, or fever with pelvic pain. Call 108 if you cannot travel quickly.

Same-day: bleeding, one-sided pain, dizziness or shoulder-tip pain, which together can indicate an ectopic pregnancy and are a medical emergency.

This article is general information, not medical advice, and is no substitute for personal medical advice. For any decision about your or your child's health, please consult your doctor.

Frequently asked questions

Q: My scan showed a sac but no fetal pole at seven weeks. — It can mean the dates are earlier than thought. A repeat scan in one to two weeks is the standard next step before anything is concluded.

Q: Is a transvaginal scan safe with spotting? — Yes. It does not cause miscarriage and is often exactly what is needed to find the cause.

Q: What heart rate is normal at seven weeks? — Roughly 120-160 beats per minute, and it rises through the early weeks. Your doctor interprets it alongside the measurements.

Q: Can twins be seen at seven weeks? — Yes, usually, including whether they share a sac or placenta — which is the single most important thing to establish early in a twin pregnancy.