Many parents eagerly await hearing their baby’s heartbeat for the first time. There’s nothing quite like the revelation that there really is a small person growing in there!
The embryonic heart begins to beat about 22 days after conceiving (5 weeks gestation). Because the heart is so small at this point, it cannot be detected on a Doppler instrument, but an ultrasound will show the tiny heart fluttering away. After 9 or 10 weeks gestation, the baby’s heartbeat is detectable on a Doppler instrument. Sometimes you won’t be able to hear it until the 12-14th weeks of pregnancy. A Doppler is a small hand-held wand that fits in the hand, and amplifies the sound waves that are bounced back from the baby’s heart. Your doctor may apply a lightweight gel to your abdomen to help the sound travel.
A baby’s heart beat, also called fetal heart tones (FHT), starts out at 180 beats per minute (BMP), which is very rapid, much faster than an adult’s. Then around 12 weeks gestation it settles into the normal range of 120-160 BPM for the rest of the pregnancy.
A baby’s heartbeat is checked often to monitor how the baby is developing and coping with the stress of the pregnancy and labor. To measure the heart rate, your doctor will count the number of hearbeats for a full minute, or count for 15 seconds and multiply by 4. Some instruments provide a reading themselves, and some practitioners are so attuned to that all they have to do is listen carefully.
There is an old wives’ tales that suggests you can tell the gender of your baby by listening to the heart rate. A higher fetal heart rate means the mother is carrying a girl, and a lower heart rate means it’s a boy. Unfortunately, this is just a rumor!
image from made-in-china.com