How Long After Fetal Pole Should Heart Beat (And Why)?

Exact Answer – 6th week of gestation period (Approx)

One thing in this universe which can make us forget all our problems, ups and downs is a child’s smile. A child is the best gift for his/her parents. We cannot imagine the happiness which the parents would be experiencing when they see their child’s face for the first time, it’s like a dream come true for them.

The development of the baby is a beautiful process which requires a lot of patience and care. The fetal pole is the first and the earliest evidence that a fetus is developing during early pregnancy. A Fetal pole may also be referred as an embryo and it is sometimes also written as foetal pole. A fetal pole is detected by transvaginal ultrasound around 6 weeks gestation age. It occurs in the fifth week of pregnancy. The foetal pole grows at the rate of one mm per day. In a viable pregnancy, continues to grow and develop into a fetus and finally into an infant.

How Long After Fetal Pole Should Heart Beat

How Long After Fetal Pole Should A Heart Beat ?

Fetal pole is a curved structure ‘C’ shaped. One end of the fetal pole is called head and the other is called tail. The distance between the head and the tail is called the crown-to-rump length. The fetal poles length is used to find it’s age that for example if the length of the fetal pole is 6 mm then the age of this fetal pole is considered to be 6 weeks, however it is just an approximation. The doctor might suggest you to go through a transvaginal ultrasonography procedure through which the formation of the fetal pole and it’s heartbeat could be detected.

When the fetus is about six or seven weeks old, the heartbeat of the fetus could be detected. Normal range of heartbeat is 100 to 160 beats per min. The heartbeat of the fetus is around double the heartbeat of an adult. The heartbeat should not be lower than 90beats per min other it could be a non-viable pregnancy. There are some cases when a fetal pole could be seen but it’s heartbeat could not be detected. In these cases the results could be that the pregnancy will not progress further or will end in miscarriage. These results are like the worst nightmares parents could ever have.

A fetal pole is detected if the CRL is more than 5mm. Fetal pole is the source which provides nutrition to the embryo. The following table represents the fetal pole development and heart week detection week by week-

Fetal Pole
Number of WeeksHeartbeatCRL
5 weeksNot detectable5 mm approx
6 weeksDetectable nearly
100-120 bpm
7 weeksDetectable nearly
120-159 bpm
7 mm or greater

Why Does It Takes So Long?

Women’s get very anxious and excited after listening the news of pregnancy. But this is a long process and involves nearly 4 stages.

  • Stage 1
  • Stage 2
  • Stage 3
  • Stage 4

That is why it takes time for the fetal pole to develop and detect heartbeat. And doing ultrasound again and again is not going to help as repeating this process could not develop heartbeats to the fetus rather only increase the anxiety.

Fetal Pole

What if there is a missing fetal pole?

Factors involved in the detection of the fetal pole are-

  • Size of the gestation sac
  • menstrual cycle
  • measurement error, etc.


This whole process is long and requires time. Sometimes the heartbeat of the fetal pole could not be heard at first ultrasound, which could be due to too early in the pregnancy. It could also happen because of a large abdomen or having a tipped uterus.

Missing fetal pole could have different meanings-

  • Pregnancy is dated incorrectly can range between 6 weeks and nine weeks.
  • The pregnancy has failed.

Devices used are-

For the first scan the transvaginal ultrasound or a 2D or a 3D abdominal ultrasound. A transvaginal ultrasound is also used for getting a clear image of an embryo.



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Hi! I'm Nidhi.

Here at the EHL, it's all about delicious, easy recipes for casual entertaining. So come and join me at the beach, relax and enjoy the food.


    1. Perhaps the part about the transvaginal ultrasound might make mothers uncomfortable. Any focus on that aspect in your opinion?

  1. This article provides crucial information, especially for those who are soon to be parents. Great insights about the fetal pole and the development process.

  2. The authors did a great job with this article. It’s jam-packed with vital information and truly gets to the heart of the subject matter.

  3. The information given here is really useful for people. It is amazing that these tests can be so precise and give out so much infomation through just a sound.

    1. I could not agree more, it is an incredible process and all this knowledge availability is a blessing to parents.

  4. Honestly, I understand that it is a long process but I think the amount of ultrasounds that the mothers have to go through should not be a problem. It is all for the healthy development and peace of mind.

    1. It is a tricky balance, but I believe that it is more about understanding the process than making it about the amount of ultrasound checks.

    2. But there is a limit to it, right? It can cause unnecessary anxiety all the time. There should be a better way to check the heartbeat without putting so much anxiety on the parents always.

  5. Such a great piece. The recommendations are great and well put together, but still a little too general in some aspects.

  6. This is really interesting information and important to know, especially for those who are soon to become parents. However, could the article be more engaging?

  7. Interesting read. A bit more precision on the final recommendations phase would have been appreciated, though.

    1. Yes, it is always good to have a clear understanding of the recommendations provided. Would be great to have that information.

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