The frequency and nature of the heartbeat of a baby's future is in fact a mirror of his condition. The heart develops more complex and longer than other human organs. His embryo is laid on the fourth week of pregnancy and externally represents a hollow tube. Somewhere in the week of the 5th, the first contractions appear, and by 8-9 weeks the heart of a small man in the womb becomes the same structure as an adult: a four-chambered one, consisting of two atria and two ventricles. However, the heart of the fetus is still different in the womb of the mother: it has an oval window (a hole between the right and left atria) and an arterial duct (a vessel that connects the aorta and the pulmonary artery), since the baby does not breathe on its own, and such a structure of the heart allows access to the oxygen of the mother in all his organs. The oval window closes, and the arterial duct subsides immediately after the baby is born.
Palpitation of the baby is the main indicator of its viability. If it is less than 85-100 beats per minute or more than 200 beats - this is a serious reason to worry. If a baby, when he reached his embryonic length to 8 mm, does not hear a heart, then the pregnancy is likely frozen.
Rare can be cardiac contractions due to the fetal placental insufficiency and intrauterine hypoxia of the fetus. This may be the case with pelvic presentation of the fetus. It's bad if the baby does not have more than 70 beats per minute for more than a minute.
The longer the gestation period, the better the heart is heard. The doctor must - with every examination - listen to these tapping. Listens to the doctor by his
method of auscultation. By the way, this is the easiest way. The doctor listens to the baby with an obstetric stethoscope. It's such a small tube with a wide funnel.
The point where the heart is heard is best, below the navel: on the right or on the left, depending on where it turned the backrest. But this is only with the head preposition. If the presentation is transverse, the heartbeat is well audible at the level of the navel: again, to the right or to the left, looking where he turned the head. And above the navel, the heart is tapped when the baby is in the pelvic position.
At the very beginning of pregnancy, the fetal heart rate is determined through ultrasound. With vaginal uzi, embryonic heart lesions are detected at 5-6 weeks of gestation. If the sensor has a doctor on the stomach, then the heart can be heard in 6-7 weeks. The frequency of contractions does not change in the first trimester of pregnancy. But further - it goes to increase. In 6-8 - it's 110-130 beats per minute, in 9-10 weeks - 170-190 strokes, and from the 11th week and until the birth - 140-160. All this is connected with the development of that part of the nervous system, which is responsible for the internal organs of the fetus.
In later terms, the frequency of contractions depends on the movement of the baby, what kind of load goes to the mother (including, and illness, and cold, and excessive heat). If the oxygen is not enough, the number of cuts increases - above 160 beats per minute (tachycardia). And then - on the contrary - reduces to 120 strokes (bradycardia).
Ideally, the baby should have rhythmic tones - arise at regular intervals. Arrhythmic in children with congenital heart defects or intrauterine hypoxia. The tone of the heartbeat should be clear: they are very clearly heard. If they are deaf, then the baby does not rule out hypoxia.
You can not hear the baby's heart badly and if the placenta is located on the front wall of the uterus, or if the mummy has water hydration or low blood pressure. Still it is possible from a multiplicity, excessive thickness of a forward abdominal wall at adiposity, excessive activity of the baby itself.
In the second and third path of ultrasound, more attention is paid not so much to the palpitations as to the correct location of the heart in the chest.
You can also conduct echocardiography - this is a more detailed study of the baby's heart. And at week 32, you can examine the heart - cardiotocography. Then the heartbeat of the fetus and uterine contractions are simultaneously recorded.