The 6th week of pregnancy has a fetal heart, but the 9th week does not have a fetal heart, why?

Question
Hello doctor,
I went to the antenatal clinic at 6 weeks and had a fetal heartbeat. Now I am 9 weeks, I went to the doctor again and there was no fetal heartbeat. The doctor told me the 6th week of pregnancy has a fetal heart, but the 9th week there is no fetal heart, what is the reason? Thank you doctor.
Nguyen Thi Ngoc Diem (1984)
Answer
Answered by Specialist I Nguyen Thi Minh Huyen - Obstetrician and Gynecologist - Department of Obstetrics and Gynecology, Vinmec Nha Trang International General Hospital.
Hello,
With the question "The 6th week of pregnancy has a fetal heart, but the 9th week does not have a fetal heart, why? , the doctor would like to answer as follows:
During fetal development, the heart begins to form quite clearly and beat about 22 days after conception, often before the mother realizes she is pregnant. Fetal heartbeat will usually appear at 6-7 weeks of pregnancy, at this time with modern ultrasound techniques, we can hear the fetal heartbeat.
However, in many cases, it is not until about 8 - 10 weeks of pregnancy that the fetal heartbeat can be heard, this depends on the menstrual cycle as well as the development of the embryo. During this stage, the heart develops from a simple tube shape then twists and divides, eventually forming the four chambers and heart valves (which open and close blood to release blood from the heart to all over the baby's body). From the 20th week onwards, the fetal heart beat has become strong and now just need to use normal headphones to be heard.
An embryo at 9 weeks, the image of the embryo is also quite clear, so it is easy to observe the fetal heart activity and record the fetal heart doppler. When no fetal cardiac activity is recorded and no fetal heart rate doppler is recorded, it means: The fetus has stopped progressing. As for the reason for the stillbirth and how to handle the stillbirth, the obstetrician will give you detailed advice. Therefore, you should visit your doctor for specific advice.
If you still have questions about the 6th week of pregnancy with the fetal heart but the 9th week without the fetal heart, you can go to the hospital of Vinmec Health System for further examination and advice. Thank you for trusting and sending questions to Vinmec. Wishing you lots of health.
Best regards!