One of the most important stages of a healthy pregnancy follow-up is the second level ultrasound examination, in which all organs and formations of the developing baby are examined in detail.
Different names are given to this examination, such as second trimester ultrasonography scan, detailed fetal examination, and detailed fetal anatomical examination. Among the people, it is also misnamed as color ultrasound.
Detailed ultrasonography 18-24. can be done within weeks. During this period, the baby and its organs have grown enough and the amount of water around the baby is abundant in order to obtain a better image. Another reason why it is done during this period is that it is not too late to terminate the pregnancy in case a possible anomaly is detected. In our center, the application is 20-22. done between weeks.
It is appropriate to use an ultrasound device with superior technical features in order to make the evaluation soundly.
It is ideal that detailed ultrasonography be performed by people who have received special training in this regard.
The aim of detailed ultrasonography is to detect congenital defects that can be seen in the baby and to detect anomalies that may occur in some genetic diseases and to carry out further examination if necessary. However, despite all these developments in technology, only 70-80% of congenital defects can be noticed even in the presence of the best devices and the most experienced specialists.
How is detailed ultrasonography done?
In detailed ultrasonography; uterus structure, placenta (baby partner) and baby are reviewed systematically.
The expectant mother is examined in the supine position by looking at the abdomen. The process takes about 15-20 minutes. After the general evaluation of the baby and routine measurements, the head, neck, rib cage, heart, abdomen, genital area, arms and legs and spine are examined in detail, respectively.
What is checked in detailed ultrasonography?
1) The shape, structure, diameter and circumference of the head are measured.
2) Brain cavities, choroid plexus (choroid plexus), midbrain, posterior pit (posterior fossa), lateral ventricles, which are intracranial formations, are examined and their measurements are made. The baby’s cerebellum is seen in the back of the brain in the form of a spectacle. The length of this structure usually gives the gestational week. Detection of enlargement of the ventricles or cysts in the choroid plexuses may be important.
3) On the face, the general profile of the baby, the nasal bone, the eyeballs and the distances between them are examined. The lens in the baby’s eye is observed in ultrasonography.
4) It is examined whether there is any cyst or mass in the neck. Nape thickness may also give clues in terms of genetic diseases in this period.
5) The entire spine is examined from top to bottom and in cross-sections to determine whether there is an opening. The entire spine is examined from the nape to the coccyx.
6) The general structure of the heart is examined, and it is checked whether there is an abnormality in the beat rate and rhythm. The ventricles and atria (ventricles and atria) are examined, and it is investigated whether there is a mass or an abnormal appearance in them. It is checked whether there is a hole between the ventricles or atria. The structure of the aorta, which is the main artery coming out of the heart, and the main vessels that carry the dirty blood to the lungs are examined.
7) The structure and shape of the thorax is examined, it is checked whether the lungs and diaphragm appear normal.
8) Stomach, liver, kidneys, bladder, abdominal wall, the area where the umbilical cord enters the baby and the course of the vessels after they enter the baby are examined and the abdominal circumference is measured. In addition, the ultrasound image of the intestines can give an idea in terms of genetic diseases.
9) Arms and legs All bones in the arms and legs are measured. These are the humerus between the shoulder and the elbow, the radius and ulna bones between the elbow and the wrist, the femur between the hip and the knee, and the tibia and fibula between the knee and the ankle. By examining the structure of the hands and feet, it is investigated whether there is a number and deformity. For example, the absence of the bone in the middle of the little finger is interpreted in favor of Down syndrome.
Basically, many major anomalies can be detected in detailed ultrasonography, but it is not possible to detect all anomalies with 100% certainty.
Evaluation of the baby’s development with ultrasound depends on several factors. Among these, the most important ones are the mother’s body weight and the amount of fat and the position of the baby in the womb. The amount of amniotic fluid also affects the quality of the ultrasound examination. In some cases, the baby’s posture may not allow the examination of certain areas. This occurs in approximately 10-15% of pregnant women.
In general, more than half of the anomalies can be detected by ultrasonography. Accordingly, the fact that detailed ultrasonography findings are normal does not guarantee that the baby is absolutely healthy.
