It is important to know the answer to the question of when the fetus’s heartbeat begins for the pregnant woman to know when her fetus is at risk, and when the situation is healthy, and the following paragraphs explain the stages of the development of the fetus’s heartbeat and the number of its heartbeats each week, in addition to methods of measuring the pulse, and disorders that may affect the fetus’s heart.
When does the fetal heartbeat start?
The heart of the fetus is formed and developed with the passage of the fourth week of pregnancy, but the pulse does not start here; The heart still looks like a twisted and divided tube, and during the fourth week of pregnancy the heart and valves are formed (to be ready to pump blood to the fetus), and by the fifth week, the heart tube begins to beat spontaneously, but it cannot be heard, and during the first few weeks, blood vessels begin The precursor is also in development in the fetus.
In the sixth week, a baby's heart can beat at 110 per minute, and it contains four hollow chambers, each with an inlet and outlet to allow blood to flow in and out of each chamber.
With the development of the baby’s heart, the mother will be able to hear the baby’s heartbeat for the first time during the ninth or tenth week of pregnancy, and its pulse will be about 170 beats per minute, and then it will slow down from now on, and the fetus’s heartbeat can be heard from the Doppler device upon ultrasound examination.
Fetal heartbeat development stages
It is possible to see the first visible sign of the fetal heart known as (the fetal pole) when the pulse begins around the fifth or sixth week of pregnancy, but before the eighth week of pregnancy, the doctor will not be able to hear the baby’s heartbeat on the device, and by the tenth week it can be heard clearly The following are the stages of fetal heartbeat development from its beginning to the tenth week:
- Week 5: The developing heart consists of two tubes fused in the middle, creating a stem with four branching tubes. The heart begins to beat and can be detected by transvaginal ultrasound.
- Sixth: The heart of the fetus changes a lot; Because the main cardiac tube has been formed, the heart is in the shape of an S and the ventricle region begins to develop.
- Seventh: The ventricles and atria of the heart begin to separate and develop.
- Eighth: The valves are formed between the atria and ventricles in the heart.
- In the ninth and tenth weeks: The aorta and the pulmonary vein are formed, and by the tenth week, the fetus's heart is fully developed.
- During the 18th and 22nd weeks of pregnancy: the fetal heart can be examined using ultrasound; To detect any congenital defects, its general heart rate is between 110 and 160 beats per minute.
Fetal heart rate method
The woman is subjected to an examination to detect the heartbeat of the fetus in several stages of pregnancy, and the first examination may be as early as the seventh week, especially if the woman suffers from bleeding or problems in a previous pregnancy.
- Vaginal examination: In the early stages of pregnancy, usually before week 11, a transvaginal ultrasound can help detect the fetus's heartbeat, and can also be useful after week 11, if an abdominal examination does not provide a clear picture of the fetus.
- Abdominal examination: During the second and third trimesters of pregnancy, an examination of the abdomen can help in evaluating pregnancy, through an ultrasound machine; Because by the second trimester of pregnancy, the fetus's heart is fully formed, and the doctor must see the heart beating in the examination.
- Monitoring the fetal heart rate: There are two ways to monitor the fetal heart rate at the time of labor, they are auscultation with a stethoscope or a Doppler device or electronic fetal monitoring that uses specialized internal or external equipment to measure the heart rate.
- Dopson: It is a non-prescription fetal heart rate monitor that can be used at home, but it may expose the fetus to unsafe energy levels.
Possible heart defects in the fetus
Heart defects can develop in the womb, and if the heart and blood vessels fail to develop properly during fetal development, this may cause the following:
- A blockage that blocks blood flow around the heart and arteries.
- Abnormal blood flow through the heart, such as openings in the walls separating the two sides of the heart.
- Congenital defects in parts of the heart.
Causes of heart defects in the fetus
In about eight in 10 cases, the cause of a congenital heart defect is unknown, and some known causes of coronary artery disease include the following:
- Genes: 20% of cases have a genetic cause.
- Other birth defects: such as the child having certain birth defects, such as Down syndrome; are more likely to have heart defects.
- Maternal diseases: A mother's illness during pregnancy with German measles, for example, increases the risk of congenital heart disorders.
- Medications and drugs: Medications (over-the-counter or prescription) or drugs that the mother takes during pregnancy can increase the risk of congenital heart disorders.
- Alcohol: Alcohol during pregnancy increases the chance of developing congenital heart disorders.
- Maternal health: Factors such as uncontrolled diabetes and poor nutrition during pregnancy increase the risk.
- Maternal age: Babies of older women are more likely to have birth defects than children of younger women.
Delayed fetal heartbeat
There are several possible reasons for the absence of a heartbeat in the fetus or the lack of detection of the pulse using ultrasound, and when the heartbeat is not heard, it is recommended to repeat the ultrasound examination after a week, and the possible causes are the following:
- Ultrasound type: The transvaginal ultrasound is much more accurate than the abdominal ultrasound at the beginning of pregnancy, and before the eighth week it is preferable to use transvaginal ultrasound.
- Gestational age: If the gestational age is less than seven weeks, it is unlikely that an ultrasound will help to hear the fetus's heartbeat.
- Accuracy of appointments: If the fetal heartbeat does not appear using the transvaginal ultrasound in the seventh week, the estimation of the gestational age may be wrong, and the pregnant woman needs to wait another week.
Reasons for a delayed fetal heartbeat
If the pregnant woman undergoes an ultrasound a week after the last examination, and the pulse has not yet appeared, the possibility of miscarriage is great, in contrast, if the cycle was not regular before pregnancy, the gestational age may be wrong, and it has not passed 7 weeks after pregnancy, and you can wait for the 12th week For another ultrasound, especially if the mother has previously heard the fetus's heartbeat.
Maintaining the heartbeat of the fetus
Monitoring the fetal heart rate is useful if the pregnancy is very dangerous, that is, when the pregnant woman has high blood pressure, diabetes, or if the child's development is not as it should, and there are two ways to monitor the fetal heart, external and internal:
External monitoring of the fetal heart
In this method, a device (Doppler) is used to listen to and record the fetal heartbeat through the abdomen, an ultrasound device, which is often used during prenatal visits to determine the number of the fetus’s heartbeat, and can be used during labor, and used by installing the ultrasound probe abdominal ultrasound; To send the fetal heart sounds to the computer, and to display the rate and pattern of the fetal heart rate on the screen.
Internal fetal heart monitoring
This method uses a thin wire that is placed on the fetus's scalp through the cervix and is attached to a monitor. This method gives better readings. Because movement does not affect it, it cannot be used if the fluid-filled sac surrounding the baby ( amniotic sac ) has ruptured and the cervix has opened, and it is used only when external monitoring does not give a good reading.
Dealing with abnormal pulse defects
The early heartbeat may not have any effect on the fetus, but if the heartbeat accelerates or slows, it causes heart failure, whether in the womb or at birth, and supraventricular tachycardia may require prenatal treatment; Because it may lead to heart failure, and treatment is through medications and monitoring in the hospital, but after birth, the child may or may not need treatment.
The previous paragraphs talked about the answer to the question of when the fetus’s heartbeat begins. Usually, the pulse begins by the sixth week. But if the pregnancy date is calculated incorrectly, the pulse will be delayed at least a week, and the pregnant woman needs to know the rate of the fetus’s heartbeat every week; To notice any heart muscle problems that require medical treatment.
Comments
Post a Comment