When an Ultrasound Shows a Heartbeat in Early Pregnancy | 合法醫療器材資訊網

2021年3月9日—Atransvaginalultrasoundmayshowafetalheartbeatby8weeksofpregnancy.Later,doctorsuseabdominalultrasoundsandDopplerstosee ...

While the heart of a fetus[1] is still developing, it may be detectable by ultrasound as early as 6 weeks[2] gestation. Technically, it is not a fetus at this point but an embryo, and the heartbeat is only visible on an ultrasound, not audible this early in pregnancy. 

The babys heart develops from two tubes that join together in the middle to create a chamber with four tubes extending from it. It starts to beat between 5 and 6 weeks gestation and may be detected via ultrasound[3] around this time as well. The heart of the embryo continues to develop over the next several weeks. It is fully formed around 10 weeks gestation.