In most cases, a fetal Doppler will be able to detect a heartbeat by the end of the first trimester (around 12 weeks). Some providers do not begin checking for the heartbeat with a Doppler device before then to avoid causing unnecessary worry.
What Is a Baby Doppler?
A fetal Doppler, also known as a baby Doppler, is a handheld ultrasound device used to detect a fetal heartbeat. The device detects movement through sound waves. It is traditionally used in a medical office by healthcare providers to hear your baby’s heartbeat. To check for a fetal heartbeat, your provider uses a Doppler wand along with some ultrasound gel. The procedure is similar to a transabdominal ultrasound used to visualize a fetus in the uterus. Most baby Dopplers have a digital screen, which displays the fetal heart rate number. At six weeks of pregnancy and beyond, the normal fetal heart rate is between 110 and 160 beats per minute, but it may vary slightly.
Why Can’t I Hear My Baby’s Heartbeat With a Doppler?
If your provider did not find your baby’s heartbeat with a handheld Doppler and you have not yet reached 12 weeks gestation, it may just be too early. There are other reasons for not hearing a heartbeat with a baby Doppler, too. These include gestational age, position of the placenta, position of the uterus, and potential pregnancy loss.
Gestational Age
Gestation is how far along you are in your pregnancy. A doctor will usually use a transvaginal ultrasound in early pregnancy to visually see on a monitor how a fetus is developing. If your due date has been miscalculated (perhaps you are not as far along as you had guessed), it’s possible a heartbeat won’t be detectable with a Doppler just yet.
Position of the Placenta
The fetal heartbeat could be muffled depending on the location of the placenta. If you have an anterior placenta (a placenta located toward the anterior or “front” of the uterus), it can serve as an additional layer between the Doppler and the fetus that makes the heartbeat more difficult to detect.
Position of the Uterus
A tilted uterus, also known as a tipped or retroverted uterus, can contribute to the inability to detect a fetal heartbeat. Retroverted simply means that the uterus is positioned toward the spine rather than horizontally over the bladder. This position is a normal body formation that occurs in one in five people with a uterus. A retroverted uterus may initially make it hard to hear baby’s heartbeat. But as pregnancy progresses, the uterus will often turn toward its intended position by 14 to 16 weeks.
Pregnancy Loss
If a doctor does not find a heartbeat during a fetal Doppler exam, particularly if they have heard one previously, it is possible you may be experiencing a miscarriage. Your doctor may order further diagnostic testing to determine exactly what is happening.
Home Baby Doppler Cautions
The idea of being able to check in on your baby’s heartbeat whenever you like can be extremely tempting, especially for people with high-risk pregnancies or those who are pregnant with a rainbow baby. It can be difficult to wait until the next routine prenatal visit to get reassurance that everything is OK. While fetal Dopplers are available over the counter, most experts caution against using them. For one, the Food and Drug Administration (FDA) advises against unregulated home use of fetal Dopplers. The FDA notes there are unknown long-term effects of such devices, and uncontrolled exposure could potentially be harmful. Additionally, when a heartbeat monitor is used without a healthcare professional’s supervision, it can lead to problems. For example, an expecting parent might not consult their doctor when they should because of the false sense of security provided by hearing what they believe is their baby’s heartbeat. But there is the issue of accuracy: You may think you’re hearing baby’s heartbeat with an at-home fetal Doppler when in fact, you could be hearing your own blood flow or that of the placenta. Conversely, without training, you may not easily find a heartbeat when there is one, which can cause a lot of unnecessary anxiety. A trained healthcare professional can best recognize and interpret the sounds from a Doppler device.
A Word From Verywell
Many expecting parents look forward to hearing a heartbeat with a fetal Doppler at their prenatal visits, but the lack of an audible heartbeat—even for just a few moments—can cause a flood of negative feelings. In addition to having regular prenatal care and an open dialogue with your provider, knowing about the limitations of baby Doppler devices can ease any anxiety.
