The mother's first acquaintance with her baby occurs during the first ultrasound study. Each study has its own tasks and must be carried out at a certain time. The first planned ultrasound is from the tenth to the twelfth week. The purpose of the first ultrasound is the elimination of chromosomal abnormalities, the clarification of the gestation period and the elimination of gross malformations of the fetus.
In the second ultrasound study, which is conducted during the period from the twentieth to the twenty-second week, the specialist considers the structure of the organs, examines the central nervous system and the possible vices of the cardiovascular system. Right now you can already determine the sex of the child.
The terms of the third ultrasound in pregnancy lie within the limits of 32-34 weeks. The main goal of this study is to determine the presenting part of the fetus and to exclude the delays and malformations of the baby.
The tasks of the third planned ultrasound in pregnancy
Ultrasound of the 3rd trimester is the last screening ultrasound , that is obligatory, which passes the future mother.
Explanation screening ultrasound 3 trimester will enable:
- Determine the position in which the baby is in order to determine the strategy of conducting labor: natural or caesarean section.
- Specify the anatomical data of the fetus: the size, the expected mass, and also the correspondence of the obtained data to the term of pregnancy. On ultrasound in the 3rd trimester, it is possible to detect infection of the fetus, due to the transmitted infections by the mother herself, some vices that were not identified at earlier times. Also, screening for ultrasound in the trimester can detect changes in the cerebral cortex.
- Determine the amount of amniotic fluid. If the amount of amniotic fluid significantly deviates from the norm in a greater or lesser direction, this may indicate a change in the anatomical data of the fetus. First of all, pay attention to the stomach, the bladder of the fetus.
- Eliminate possible complications, such as the appearance of voluminous formations, incompetence of the cervix, i.e. Those that could prevent spontaneous childbirth.
During the ultrasound examination, the respiratory and motor activity of the fetus is assessed, the placenta is examined: its location and thickness, the presence of pathological inclusions in its structure. This study also makes it possible to determine the maturity of the fetus and the expected date of delivery.
Norms of the third ultrasound in pregnancy
For the conduct of ultrasound in the 3rd trimester, there is a rigid protocol, according to which the physician should conduct an examination of the pregnant woman and obtain accurate data on the development of the fetus. This protocol gives a clear idea to the obstetrician about the condition of the pregnant woman and her future child. This document will help the doctor promptly respond in any situations that may occur during childbirth. In the norm of ultrasound, the trimester should carry the following information.
The number of fruits, their position. It is good, if the fetus has a head previa. Also, the conclusion of ultrasound has such indicators:
- BPR - the norm of 7,6-9,1 cm;
- OZH - the norm of 8-10.3 cm;
- OG - the norm of 8.7-10.4 cm;
- LZR - the norm of 9.9-11.7 cm;
- DB - the norm of 5.7-7.1 cm.
When 3 ultrasounds are done (32-34 weeks), the weight of the fetus should be within the range of 2248-2750 g. The thickness of the placenta should not go beyond 26.8-43.8 mm. The placenta ends the migration by the beginning of the third trimester and takes the position in which it will be before delivery. Also assess the degree of maturity of the placenta, starting at 34 weeks, it should have a second degree of maturity. The amount of amniotic fluid should not be more than 1700 ml. Many or little water can indicate the presence of pathologies in the fetus.