When Do You First Hear a Heartbeat in Pregnancy?

When Do You First Hear a Heartbeat in Pregnancy?

The journey of a baby's heartbeat begins approximately 22 days after conception, marked by embryonic cardiac activity, which represents the earliest pulses of what will eventually become your baby's cardiac cells. However, during this initial stage, this "heartbeat" remains elusive, despite pulsing at an average rate of 110 times per minute. Nevertheless, thanks to the marvels of ultrasound technology, you and your doctor will soon have the opportunity to hear your baby's heartbeat. However, with advancements in technology and a heartwarming twist, parents now have the opportunity to record and cherish their baby's first heartbeat using a special keepsake - the recordable heartbeat teddy bear.

Around 5 to 6 weeks into pregnancy, a flickering of cells emerges within the embryo's torso, signaling the formation of the heart tube. However, it's important to note that the heart, at this point, is far from the fully developed, four-chambered organ we recognize. Instead, it assumes a tube-shaped structure that requires further development. This heart tube undergoes intricate twists and turns, gradually evolving into the complete heart, including its chambers.

The American College of Obstetrics and Gynecologists (ACOG) designates this early movement as "cardiac activity," refraining from terming it a heartbeat since the heart has not yet assumed its final form. As ACOG explains, what pregnant individuals may perceive as a heartbeat on ultrasound machines is actually the translation of electronic impulses representing fetal cardiac activity into the familiar sound pattern of a heartbeat? ACOG advises waiting until the heart is fully formed before using the term "heartbeat."

The development of a baby's heart is one of the earliest and most critical milestones, as it is essential for delivering oxygenated blood and nutrients to other developing organs within the growing fetus.

Key stages in the development of the heart include:

1. The heart tube undergoes twisting and bending, gradually assuming an S-shaped configuration. The lower portion of the line eventually forms the two upper heart chambers, known as the atria.

2. The middle section of the heart tube transforms into the two lower chambers or ventricles.

3. Walls develop to divide the heart chambers, creating distinct entrances and exits for the flow of blood.

4. Valves form between the ventricles and major blood vessels like the aorta and pulmonary artery.

Around the 10 to 12-week mark of gestation, the heart reaches its fully formed state. During this period, small blood vessels begin to form and fill with blood. At birth, the opening between the two atria closes, marking the baby's oxygen supply transition from the placenta to the lungs.

Read Also:- Parents Should Limit Screen Time

What to Expect at Your First Pregnancy Ultrasound

Following a positive pregnancy test, your doctor may recommend an early pregnancy ultrasound around 7 1/2 to 8 weeks. Some practices schedule it between 11 and 14 weeks. It can be as early as 6 weeks if you have a medical history or complications.

During this appointment, the doctor or ultrasound technician will:

1. Confirm a viable pregnancy and rule out molar or ectopic pregnancies.

2. Verify the baby's heartbeat.

3. Measure the baby's crown-to-rump length to determine gestational age.

4. Assess for any abnormal gestation.

5. Monitor the baby's heart rate.

Typically, the baby's heartbeat ranges from 90-110 bpm at 6 to 7 weeks and increases to 140-170 bpm by the ninth week. However, you might not hear the heartbeat during the first ultrasound, often due to early pregnancy or other factors.

Possible reasons for not hearing the heartbeat include a tipped uterus, a large abdomen, or being less far along than expected. If no heartbeat is detected, your doctor may recommend a follow-up ultrasound in 1 to 2 weeks.

In cases where there's no fetal heartbeat in an embryo with a crown-rump length over 5 millimeters after week 6, further evaluation and tests may be necessary. A 1999 study showed that if a heartbeat is detected at 6 weeks, there's a 78 percent chance of the pregnancy continuing, rising to 98 percent at 8 weeks and 99.4 percent after 10 weeks.

Read Also:- Where to Donate Stuffed Animals for Kids?

Which Instruments Are Employed to Listen to a Baby's Heartbeat?

During your initial prenatal scan, either your healthcare provider or a skilled ultrasound technician will utilize specific devices to detect and monitor your baby's heartbeat. These devices include transvaginal ultrasound, 2D ultrasound, and 3D ultrasound.

The transvaginal ultrasound is commonly employed in the early stages of pregnancy to obtain a detailed image of the developing embryo. This procedure helps in assessing the embryo's growth and development with precision.

In addition to the transvaginal ultrasound, 2D ultrasound is frequently used. It provides a two-dimensional, flat image of the fetus and surrounding structures. This type of ultrasound is valuable for monitoring the baby's progress and ensuring its well-being.

For a more comprehensive understanding of the fetus's dimensions and the position of surrounding organs, a 3D ultrasound may be utilized. This advanced technique offers a three-dimensional view, enabling healthcare providers to assess the width, height, and depth of the fetus and its relationship to its internal organs. This added dimensionality can provide valuable insights into the baby's development and overall health.

Read Also:- Interesting Facts About Teddy Bears

Changes in Fetal Heartbeat Across Pregnancy

During the course of pregnancy, your baby's heart undergoes significant developmental changes. Initially, the fetal heartbeat starts at a rate of 90 to 110 bpm in the early weeks of pregnancy. As pregnancy progresses, it gradually increases, reaching a peak at around weeks 9 to 10 when it typically falls between 140 and 170 bpm.

Subsequently, in the second and third trimesters, a normal fetal heartbeat is considered to be between 110 and 160 bpm. It's important to note that your baby's heartbeat can exhibit variations throughout pregnancy, with fluctuations occurring at each prenatal appointment.

Your healthcare provider may express concern if your baby's heartbeat is excessively slow, fast, or irregular. In such cases, there is a rare possibility of an underlying heart condition in your baby. To ensure your baby's well-being, your doctor will closely monitor the heartbeat at each prenatal checkup.

If your doctor harbors any concerns regarding the development of your baby's heart, they may recommend a fetal echocardiogram, a specialized ultrasound examination designed to provide a comprehensive assessment of your baby's cardiac health.

Are Home Fetal Dopplers Safe to Use?

The Food and Drug Administration (FDA) advises caution when using at-home fetal Doppler devices. These handheld Doppler units are classified as "prescription devices" by the FDA, and their usage is recommended only under the supervision of a healthcare professional.

It's important to note that there is no conclusive evidence suggesting that Doppler devices pose a direct risk to the developing baby or the expectant individual. However, in cases of low-risk pregnancies, most experts do not encourage excessive prenatal testing.

While these devices are not known to cause harm, there is an ongoing debate regarding whether regular, unsupervised use to check for a fetal heartbeat is advisable.

Back to blog

Leave a comment

Please note, comments need to be approved before they are published.