The first meaning is 'metre' which is a measurement of length. If the 'm' stands alone it is metre. The second meaning is 'milliâ¦' which means a thousandth. In this case 'm' can not stand alone, we need to know what we have a thousandth of; if it is weight, length or some other thing. Example: mg means 'milligram', a thousandth of a gram. Example: mm means 'millimetre', a thousanth of a meter.
At about six weeks into pregnancy (four weeks from conception), you should be able to see your baby's heartbeat on ultrasound. The typical heart rate at this age is about 100 beats per minute.
How soon can my babyâs heart beat be heard? Prenatal Testing No comments Your babyâs heart begins beating around 22 days after conception, about 5 weeks after your last period. At this stage, the heart is too tiny to hear even with an ultrasound. However, it may be detected as early as 4 weeks after conception as a flickering in the chest via ultrasound. After 9 or 10 weeks of pregnancy, you might be able to hear your babyâs heartbeat. Typically your physician will use a Doppler instrument to do this. A Doppler instrument bounces sound waves off the fetal heart. These sounds return, affected by what they bounced off of, and the changes in these waves are picked up by the receiver in the Doppler.