By the child’s heartbeat in the uterus, the gynecologist can determine whether the baby is receiving enough oxygen and his general condition. In the early stages of pregnancy, the baby’s heartbeat can only be heard with the help of special devices, while from the middle of the second trimester, the doctor listens to the heart with a wooden tube with an obstetric stethoscope.
Young expectant mothers are concerned about the question, when does the heartbeat appear in the fetus during pregnancy? The pulsation of the heart in the unborn child begins on the 21st day after conception. The frequency of its contractions differs in different weeks of pregnancy.
Fetal heart rate at different stages of pregnancy
With each week of embryo development in the uterine cavity, its heart rate also changes, which is caused by the progressive development of the autonomic nervous system, which is responsible for the functioning of the heart. Below is a table of the fetal heart rate by the week of pregnancy.
At the 5th week of gestation, the unborn child’s heart rate is approximately the same as the mother’s heart rate, 80-85 beats/min. Within a month, this indicator increases by several beats every day. Thus, by the end of the 1st trimester of pregnancy, the heart rate of the child is 170-175 beats/min.
Starting from the 15th week of pregnancy and until the end of the entire gestation period, the gynecologist regularly checks the work of the child’s heart in the womb at every appointment in the antenatal clinic – by listening with a stethoscope through the anterior abdominal wall, using ultrasound, portable Doppler. From the 15th week of pregnancy, the number of fetal heartbeats per minute should not exceed 160-170 beats/min if these figures are higher. The onset of oxygen starvation in the baby can be suspected, and if the heart contracts less than 130 beats/min, then they speak of acute hypoxia, which can threaten the development and even the life of the child. Strict heart rate control is also necessary for the baby during delivery, especially during contractions and attempts, normally 140-160 beats/min. Some indications require continuous monitoring of the baby’s heartbeat during childbirth with a CTG device. These include:
- Delayed intrauterine development of the child against the background of severe hypoxia.
- Multiple pregnancies (natural birth of 2 or more fetuses).
- Stimulation of labor activity with a dropper with oxytocin.
- Epidural anesthesia for a woman in labor.
- Delayed pregnancy.
- Childbirth began before the 37th week of pregnancy.
- Chronic diseases in the mother and disorders in the functioning of the nervous system.
What should be paid attention to when listening to the fetal heart?
The heart formation in the embryo begins at the earliest stages of embryogenesis, and the work of this organ is an important indicator of the development of the unborn child and his state of health. Listening to the fetus’s heart rate is necessary throughout pregnancy and during childbirth since these indicators suggest various pathologies of the child’s body at an early stage of their development.
When can a fetal heartbeat be heard on an ultrasound? Even though the pulsation of the rudiment of the heart in the embryo begins from day 21, on ultrasound, you can listen to heartbeats only at 6-7 weeks of gestation since, at this time, the hollow tube begins to turn into a full-fledged four-chamber organ with two ventricles and two atria.
When listening to the heart of an unborn child, pay attention to the following indicators:
- Heart rate – a heart rate of more than 185 beats/min is called fetal tachycardia; less than 100 beats/min is called bradycardia. These conditions are not norm indicators and require clarification of the cause. The fetal heart rate should not exceed 170 beats/min in the second and third trimesters.
- Heart sounds are normal in a healthy child who develops fully in utero, heart tones are clear and resonant, and in the presence of defects or developmental anomalies, contractions are not heard clearly and are blurred.
- Heart rate – myocardial contractions are repeated rhythmically at regular intervals in a healthy fetus that develops according to the gestational age. In acute hypoxia or anomalies in the development of the heart valves, arrhythmia, the gallop rhythm, is heard.
Methods for listening to heartbeats in a child in the womb
There are several ways to listen to the heartbeats of the fetus in the uterus, depending on the gestational age.
Ultrasound
Starting from the 5th week of pregnancy, it is possible to evaluate the work of the heart in an unborn child only with the help of an ultrasound sensor – transvaginally and transabdominal. In the early stages of pregnancy, ultrasound determines whether there are heart contractions, whether the embryo develops, and how many beats per minute the myocardium pulsates. From week 12 to week 20, the doctor evaluates not only the heart rate, but also the location of the organ, the presence of all chambers, and the functioning of the heart valves. It is at these gestational ages that most heart defects are detected in the fetus.
Stethoscope
An obstetric stethoscope is used to evaluate the parameters of the heart muscle contraction after the 20th week of pregnancy. At each appointment in the antenatal clinic, the doctor first determines the location of the baby’s head and position in the uterus, then attaches the tube to the mother’s anterior abdominal wall and listens to the fetal heart sound. You can also use a Stethoscope from the second half of pregnancy, but it is rarely used in obstetrics. In childbirth, the heartbeat is listened to with an obstetric stethoscope every half an hour, while paying attention to the heart sounds before the contraction and immediately after it.
Cardiotocography (CTG)
From the beginning of the third trimester of pregnancy, the fetal heart rate parameters are evaluated by CTG at least once for each pregnant woman. During childbirth, this is a mandatory procedure that shows not only the number of heartbeats per minute in a child but also registers the reaction of the fetal heart muscle to each contraction.
Listening to the heartbeat of a child by week
At what week of pregnancy can you calculate the heart rate in the fetus? The only way to do this in the early stages is only with the help of an ultrasound machine. If at six weeks there is no heart pulsation on the monitor screen, then there is a possibility that the pregnancy has stopped. In such situations, the woman needs to be re-examined on another device.
At what week is the heartbeat heard in the fetus through the abdominal wall? You can hear how the baby’s heart contracts through the mother’s belly from the 20th week of pregnancy by attaching an obstetric stethoscope to the anterior abdominal wall, only first you need to determine the location of the fetus in the uterus and its position to know which side and at what height to put the tube in otherwise, nothing will be heard.
Sometimes with the help of an obstetric stethoscope, it is not possible to listen to the baby’s heart – this may be due to some conditions:
- Multiple pregnancies.
- Polyhydramnios.
- Heart defects in the unborn child.
- Overweight and edema in a pregnant woman.
- Attachment of the placenta along the anterior abdominal wall.
In such situations, a different way of listening to the parameters of the fetal heart is used. If the doctor suspects heart defects in the unborn child during an ultrasound examination, then additional fetal echocardiography is prescribed. The procedure will be informative from the 20th to the 28th week of pregnancy. Echocardiography allows you to study in detail all parts of the heart in a child and evaluate blood flow and valve function. This procedure is a mandatory study for expectant mothers over 35 years of age and for those pregnant women who already have children born with heart defects.
Starting from 28-30 weeks, all expectant mothers have been prescribed the CTG procedure, a special sensor is attached to the anterior abdominal wall, which records the parameters of the fetal heartbeat during pregnancy for a certain period. Repeated performance of such a procedure is required for women with a complicated course of pregnancy, namely:
- Late toxicosis.
- The presence of scars on the uterus after surgery and cesarean section in the past.
- Aging of the placenta ahead of time.
- Chronic diseases in the expectant mother.
- Decrease or increase in the amount of amniotic fluid.
- Intrauterine growth retardation.
- Pregnancy over 42 weeks.
CTG indicators are evaluated on a 12-point scale: 9-12 points – the child’s normal condition, he receives enough oxygen and develops fully 6-8 points – there are signs of oxygen starvation, CTG should be repeated every other day and, if necessary, prescribe treatment to a pregnant woman, 5 points or less – there is a threat to the life of the child, he suffers from acute hypoxia, the woman needs to have a cesarean section. When conducting CTG, the basal rhythm and its changes during the child’s movements are determined. Normally, the first heart rate indicator should be 130-160 beats in a calm state of the fetus and up to 190 beats with movements. Rhythm changes show how the heart rate parameters deviate on average from basal indicators, normally in a healthy fetus, no more than 5-25 beats/min.
How to listen to the fetal heartbeat on your own at home?
Many pregnant women are interested in whether it is possible to listen to the baby’s heart at home. This is quite difficult, especially in the early stages of pregnancy. Starting from the 25th week, a Stethoscope
can be applied to the abdomen, so the mother can hear her baby’s heart beating. The future dad can hear the baby’s heartbeat from the beginning of the third trimester of pregnancy, putting his ear to his wife’s stomach. In the first trimester, a woman can independently listen to the baby’s heart with the help of modern fetal dopplers.
How to determine gender by heartbeat?
There is a theory that by the number of heartbeats per minute in a baby in the womb, you can determine its gender – as if the heart beats less often in boys than in girls. Scientifically, this fact has not been confirmed in any way, although the ultrasound revealed that the heart beats evenly and rhythmically in the male fetus. At the same time, in girls, it is somewhat chaotic. The heart rate can change with the baby’s movements, a change in his body position in the uterus and stress in the mother. Therefore, by counting the number of heartbeats of the child, one or another gender can only be assumed.
Evaluation of the parameters of the heart rate of the baby in the womb is an integral part of monitoring the normal course of pregnancy. Of the nature and frequency of heart attacks in a child, the doctor may suspect development violations and complications in the expectant mother.
