The 8-week ultrasound: what changes from last week

What is visible

A fetal pole of roughly 14 to 20 mm — about the size of a rajma bean — with a clearly separate head and body beginning to form.

A strong heartbeat, typically around 150 to 170 beats per minute at this stage, which is faster than an adult's and faster than it will be later.

Limb buds for arms and legs, and sometimes small flickering movements — the embryo does move at this stage even though you will not feel anything for months.

The yolk sac is still present and will gradually disappear as the placenta takes over.

What the scan is for

Confirming location, heartbeat and number, and refining the due date. Dating at eight weeks remains highly accurate.

Checking for a subchorionic haematoma if there has been bleeding, and looking at the ovaries and uterus.

In a twin pregnancy, confirming chorionicity — whether the twins share a placenta — which is best established now and drives the whole monitoring plan.

One thing applies to every scan in India: determining or disclosing the sex of the fetus is a criminal offence under the PCPNDT Act, for the doctor, the clinic and the person who asks. The sonographer will not tell you, and asking puts them at risk of losing their registration.

Between now and the next scan

The next routine scan is usually the NT scan at 11 to 14 weeks, so this is often the last look for a month — which many women find hard.

Nausea is typically at or near its peak around now, and its presence or absence tells you nothing reliable about the pregnancy.

Keep taking folic acid, register the pregnancy if you have not, and get the booking bloods done if they are still pending.

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, severe or one-sided pain, fever, vomiting that keeps nothing down, or burning urination — urinary infections are common in pregnancy and need prompt treatment.

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: The heart rate was 172. Is that too fast? — No. Early pregnancy heart rates run high and peak around 9 to 10 weeks before settling. Your doctor reads it in context.

Q: My dates moved by a week after the scan. — Normal. Early scan dating is more accurate than period-based dating, and the new date becomes the official one.

Q: Can I have a scan without a doctor's referral? — In India, diagnostic ultrasound in pregnancy is regulated under the PCPNDT Act and requires proper documentation at a registered centre. Go through your obstetrician.

Q: Should I be worried if I feel nothing? — Movements are not felt until roughly 16 to 22 weeks. Nothing at eight weeks means nothing at all.