When Can You See the Heartbeat on Ultrasound?

Seeing your baby's heartbeat for the first time is one of the most emotional moments of early pregnancy. But when exactly can you expect to see it? The answer depends on several factors.

Table of Contents

1. When the Heartbeat Starts
2. When It's Visible on Ultrasound
3. Factors That Affect Visibility
4. What a Normal Heart Rate Looks Like
5. What If You Can't See It?
6. Abdominal vs Transvaginal Scans

When the Heartbeat Starts

The heart rate starts slow — around 80-90 beats per minute (bpm) — and accelerates rapidly, increasing by about 3 bpm per day. By 7 weeks, it's typically 90-120 bpm, and by 9-10 weeks, it peaks at 170-180 bpm before gradually slowing.

When It's Visible on Ultrasound

• Transvaginal scan: The heartbeat is usually visible from about 6 weeks (or 6+0 to 6+3). Because the probe is close to the uterus, it can detect the tiny flicker earlier.
• Abdominal scan: The heartbeat is usually visible from about 7 weeks, sometimes 6+5 in ideal conditions. The abdominal scan has to travel through more tissue, so it detects the heartbeat slightly later.

Most private clinics recommend booking your scan from 7 weeks onwards to maximise the chance of seeing a heartbeat. If you go at 6 weeks and can't see it, you may be asked to come back — which can be stressful and costly.

Factors That Affect Visibility

• Exact gestational age: If your cycle is long or you ovulated late, you might be a few days less far along than you think. This is the most common reason a heartbeat isn't visible when expected.
• Scan type: Transvaginal detects the heartbeat earlier than abdominal.
• Equipment quality: High-end ultrasound machines (common in private clinics) can detect a heartbeat slightly earlier than basic models.
• Your BMI: More abdominal tissue can make an abdominal scan harder, delaying when the heartbeat is visible. Transvaginal scans bypass this issue.
• Uterus position: A retroverted (tilted) uterus can make an abdominal scan harder.
• Sonographer skill: Experienced sonographers may detect the heartbeat slightly earlier than less experienced ones.

What a Normal Heart Rate Looks Like

A heart rate that's within these ranges is reassuring. A slow heart rate (below 80 bpm at 6 weeks, below 100 bpm at 7-8 weeks) can be a sign of concern, though it doesn't always mean the pregnancy will fail — sometimes the heart has only just started beating and will speed up.

What If You Can't See It?

1. Don't panic: The most common reason is that you're earlier than expected. Dating errors of 5-7 days are common, especially with irregular cycles.
2. Ask about the CRL: If the baby measures smaller than expected for your dates, you're probably earlier than you thought. The heartbeat may appear in a few days.
3. Book a repeat scan: The sonographer will usually ask you to return in 7-14 days. By then, the heartbeat should be visible if the pregnancy is progressing.
4. Watch for symptoms: If you experience bleeding, cramping, or a fever, contact your GP or early pregnancy unit immediately.
5. Ask questions: The sonographer should explain what they can and can't see. If you're unsure about anything, ask.

Abdominal vs Transvaginal Scans

• Transvaginal scan: Uses a slim probe inserted into the vagina. The probe sits very close to the uterus, giving a clear, magnified view. This is the best option for seeing the heartbeat at 6 weeks.
• Abdominal scan: Uses a probe on your tummy. The sound waves have to travel through skin, fat, and muscle, so the image is less clear in very early pregnancy. Better from 7-8 weeks onwards.

Most clinics will try transvaginal first at 6-7 weeks and may switch to abdominal from 8 weeks. If you have a preference, tell the sonographer — but trust their judgement about which will give the best view.

Frequently Asked Questions

Almost never. At 5 weeks, the heart is only just beginning to form and is too small and too slow to be detected by ultrasound. You might see a gestational sac, but the heartbeat comes later.

Does seeing a heartbeat guarantee a healthy pregnancy?

Seeing a heartbeat greatly reduces the risk of miscarriage, but it doesn't eliminate it. Once a heartbeat is confirmed at 7-8 weeks, the miscarriage risk drops to around 5% or lower. It's very reassuring but not a guarantee.

What's a slow heartbeat at 6 weeks?

A heart rate below 80-90 bpm at 6 weeks may be considered slow. This can mean the heart has only just started beating. A repeat scan in a week will usually show whether the rate has increased to a normal level.

Further reading:

• NHS — Antenatal care and screening

This article is for informational purposes only and does not constitute medical advice. Always consult your healthcare provider.

Last reviewed: June 2026

Related articles:

• No Heartbeat at 6 Weeks
• No Heartbeat at 7 Weeks
• Slow Heartbeat at 6 Weeks
• Fetal Heart Rate by Week