Pregnancy

When can the baby's heartbeat be seen on ultrasound? OB/GYN in Seoul, Korea

The short answer

A heartbeat usually becomes visible on transvaginal ultrasound at around 5–6 weeks of pregnancy, when the embryo is about 4–5 mm long. If your dates are uncertain or you ovulated late, it may not be visible yet, and a repeat scan about a week later is common and not a cause for alarm.

By 8 weeks the embryo is about 2 cm; by 12 weeks about 6–7 cm with visible movement. See early pregnancy symptoms and week by week.

Answered by Dami Women's Clinic (다미산부인과의원), Yeouido, Seoul · Dr. Ko Sang-hyun, OB/GYN. General information, not a diagnosis. Emergencies in Korea: call 119. Medical disclaimer · International Patient Center