How Early In Pregnancy Can A Heartbeat Be Detected On Abdominal Ultrasound?

On the abdominal ultrasound its safter to see the heartbeat at 10 weeks (8 weeks after conception). For a vaginal ultrasound you can probably see it at 6 weeks (4 weeks after conception). This depends on if you have your conception dates right as it may still be smaller than 6 weeks so it causes a lot of panic unnecessarily. 6 week vaginal ultrasounds should at most just eliminate tubal pregnancies and the heartbeat being seen be a bonus.
 
To hear the heartbeat you have to be 12 weeks (ultrasounds before that can only see them).
 
Its very easy to miss a heartbeat even at 8 weeks on an abdominal ultrasound due to fatty tissue, position of cervix, scarring if from a previous c section or endometriosis or other. Usually if there is any problem a follow up scan needs to be done a few days or a week or two later.

Though there is no hard and fast rule as such about how many weeks it takes for the heartbeat in the foetus to be detected, it is usually done at the end of the first trimester of a woman's pregnancy. A Doppler is a highly sensitive instrument which is used to detect the foetal heartbeat. It can pick up the heartbeat of a foetus by the tenth or twelfth week of the pregnancy. That is to say that when a woman is about two-and-a-half to three months into her pregnancy, the Doppler can easily pick up the faintest signs of the foetal heartbeat.

An ordinary stethoscope, on the other hand, can only pick it up during the fifth month of pregnancy. That is, by the time the ordinary stethoscope detects the foetal heartbeat, the woman is already into her 17th or 18th week of pregnancy. Other factors that affect the delay in detecting the foetal heartbeat are the excess fat which has been accumulated on the woman's body during her pregnancy and the possibility of a miscalculated due date. It is important to be patient, and if necessary, consult a doctor about getting an ultrasound scan done, which can pick up the foetal heartbeat as effectively as the Doppler.

My babys heart beat was detected by ultrasound till I was 6weeks and 6 days pregnant every pregnancy is different and sometimes its difficult to get the heartbeat when the baby is so small x

Went for a vaginal scan today and nurse said she could not find heart beat and wants me to have another scan on the 22nd may  does that mean it has miscarried or could still be alive .I'm 5 weeks pregnant they said and my last period was the 5th april

A heartbeat can usually be heard as early as 4 weeks after conception. It can be heard 3-6 weeks at the start of the pregnancy.

with my daughter it was about 2 weeks.

6 weeks