When you hear a fetal heartbeat on ultrasound
Scanning with ultrasound during pregnancy the most safe and effective method for monitoring the dynamics of the prenatal development of the fetus. This diagnostic method allows to hear the first heartbeat already in the early stages when the baby is just starting its long path of formation. And to identify pathological deviations from a baby at different stages of development to see his first movement.
The formation of the cardiovascular system in the fetus
From the beginning of the development of the cardiovascular system in the embryo until the heart rate is only 28 days. During this short period are the most important stages of formation, and if something goes wrong, then you can receive a variety of heart defects.
Formation of the heart and palpitations
The third week begins to form the heart of the double folds of the mesoderm. In the first stage of development there are two primary endocardial tubes, which after a certain time, are connected to form one double-layer of the primary heart tube. At this stage, the heart looks like a tube that does not have cameras.
At the beginning of the fourth week, the heart tube begins to split into two halves — left and right. The division is the primary partition, which at the rear there is an oval hole, it is stored until delivery. Only after when your child takes its first breath and starts the pulmonary circulation, the blood will cease to flow from the right to the left atrium, and the foramen ovale in the septum closes. Blood circulation in the fetus at this stage of development occurs from the right chamber of the heart to the left. Discharge of blood takes place in one direction.
From the fifth week of fetal heart begins to form the interventricular septum from the endocardium and myocardium, which will grow in 2-3 weeks. Between the Atria and ventricles in the septum there is a hole, it will start to close the valve since the beginning of the seventh week of gestation. Valve develops from the germinating follicles.
Obstetric on the sixth week, the heart of the embryo starts to shrink. From this period of intrauterine development of the embryo, becomes heard his heartbeat on an ultrasound.
The eighth week of the final, when the heart of the two-chamber four-chamber becomes.
On week 8 the embryo is only 1.5-2 cm, but he had already formed all the internal organs and it has its circulation.
Ultrasound: terms, when we heard the heartbeat
A fetal heartbeat can be heard at the early pregnancy ultrasound diagnosis. Using this method of research already in the period of 5 weeks is seen the fertilized egg, having the dimensions of about 7 mm, and audible heart rate that is approximately 100 beats per minute. For more informative survey on early pregnancy requires good equipment, which is able to read even the small changes.
During the study determined the presence of the ovum and its point of attachment in the uterus, counted the number of fertilized oocytes. In the embryo, it listens for the heartbeat, we study extraembryonal structure of the fetus. Uzist-gynecologist exclude the presence of hypertonicity of the uterus, which contributes to spontaneous abortion, a pathology of development of the ovum and abnormalities in reproductive organs in females (infectious diseases, neoplasms). In the Protocol of ultrasonic examination, the doctor will take the first measurements after the screening of the embryo — SVD and CTE, which will give hands on the patient after the procedure.
SVD (average inner diameter of the ovum) is the sum of the length and width of the rear of the front wall of the ovum. Each period has its own specific parameters SVD, which allow to calculate the exact date of conception.
CTE (kopchik-parietal size) — the length of the baby from crown to tailbone. This measurement also plays an important role to determine the period of fertilization. The error performances of gestational age is ±3 days. Therefore this measurement is considered the most informative.
Gynecologist-uzist has a special obstetric table, which shows all the parameters at a certain stage of fetal development. This table is included in the program of the ULTRASONIC scanner. The table allows to track the dynamics of the prenatal development of the embryo and to identify pathological discrepancies.
If you hold ultrasound in 7-14 days, then the test shows the fetus has developed arms and legs. In this period, the child makes his first movement.
If ultrasound examination in the early stages of the embryo are seen, but the gestational SAC noted, and SVD is larger than 1.5 cm, in this case, the doctor makes an unmistakable diagnosis of missed abortion.
When diagnosing an ultrasound shows gestational SAC and the embryo, but the heartbeat of the embryo is missing. Such an outcome is not a reason to panic. After all, with an irregular cycle of menstruation, it is impossible to establish the exact date of conception. Therefore, ultrasound examination will take 7-14 days. A second survey will give accurate results.
The informative value of ultrasonic examination depends on the correct calculation of gynaecologist date of conception.
If the menstrual cycle in women irregular, then the diagnosis can not hear the heartbeat of the baby. In this case, the gynecologist-uzist will reassign the procedure to another week. It is important to remember, the better the instrument is for research, the sooner you will be noticed by heartbeat. But if the size of the VDS exceeds 1.5 cm and the embryo is absent in the ovum, then it is 100% non-viable pregnancy.