Ultrasonography is the main tool in detecting congenital anomalies (birth defects) before birth. Detailed fetal ultrasonography is an ultrasonographic examination that evaluates the external and internal anatomy of the baby and detects major structural anomalies (structural defects that cause death or serious disability in the baby), as well as detecting suspicious findings in terms of chromosomal anomalies and genetic syndromes. This examination is also called detailed fetal examination, fetal anomaly screening, second trimester ultrasonography or second level ultrasonography. There are also misnomers among the public, such as color ultrasound or 3D ultrasound. Babies of women with a family history or exposure to external influences such as infection and various medications are at risk for congenital anomalies, but the majority of anomalies in babies are in the low-risk group. Therefore, this examination should be routinely recommended to all pregnant women.
What are the main purposes of detailed fetal ultrasonography?
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Confirming the baby's growth and age
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Determining the estimated time of birth
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Major structural anomalies Examination for
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Examination for markers of chromosomal anomaly (e.g. Down syndrome)
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Determining the position of the placenta (the baby's partner)
When a major structural anomaly is detected, an alternative to pregnancy termination can be offered or preparations can be made for the care and surgery of the baby with the anomaly. Again, it becomes possible to increase the sensitivity of Down Syndrome screening tests by detecting minor markers (markers that do not cause serious health problems in the baby and are frequently seen on ultrasound).
What can be done optionally in detailed fetal ultrasonography? ?
Cervix length can be measured by ultrasound to estimate the risk of premature birth in the patient group with a high risk of preterm labor.
Information before examination
Before ultrasonic examination, the patient should be informed about the potential diagnostic accuracy of ultrasonic examination, its scanning nature, and its technical and practical limitations. also thin The couple should also be informed that breastfeeding does not have a predefined duration (usually 15-30 minutes) but depends on factors such as the mother's obesity, the baby's position and the amniotic fluid (the fluid the baby is in). Following the general examination (number of babies, position of the baby in the womb, evaluation of amniotic fluid, evaluation of the placenta (baby's partner)) and measurements of the baby, a systemic examination of the baby is performed. Systemic examination includes examination of the baby's head, neck, face, respiratory system, heart and circulatory system, anterior abdominal wall and intra-abdominal organs, kidneys and circulatory system, spine, arms, legs, hands and feet, and genital area.
What should the examination protocol be like?
The physician performing the ultrasound explains the examination and checks the details and history of the patient
Shows the fetus (baby in the womb) and the heartbeat of the fetus
Makes measurements of the fetus and checks the fetal anatomy
Discusses the results with the family and gives the relevant report
General examination:An examination is made in terms of the number of fetuses (singlets, twins, etc.), the location of the placenta, the amount of amniotic fluid and the position of the baby in the womb.
Biometric examination head diameter, head circumference, abdominal circumference, and femur (upper leg bone) and humerus (upper arm bone) length are measured. Based on these measurements, the estimated weight of the baby for that week of pregnancy is calculated.
Anatomical examination
Anatomical examination includes imaging of the structures listed below. The baby's internal organs are examined in various sections, so the family may not always understand what is happening. On the ultrasound screen, bones appear white, liquid black, and soft tissues appear grayish and mottled.
-Head: The baby's head shape and intracranial structures are examined. Cerebral hemispheres (brain tissue), cerebellum (cerebellum), and cisterna magna, choroid plexuses (tissue that secretes cerebrospinal fluid), lateral ventricles (lateral ventricles), atria (posterior horn of the lateral ventricles), orbits (eyeballs), lips, and face profile is examined. It is checked for cleft palate and cleft lip. Nuchal fold thickness is measured. There is a risk of chromosomal anomaly or a risk of chromosomal anomalies in babies with increased nuchal pillar thickness. There is an increased risk of some rare genetic syndromes. The baby's profile, nasal bone, eyeballs and lens are examined. Congenital cataract diagnosis can be made before birth.
-Neck: It is checked whether there is a cyst or any mass in the baby's neck.
-Spine: The baby's spine is examined from top to bottom in longitudinal and cross sections. It is checked whether all the spinal bones are lined up in the same alignment, whether the spine is open and whether the skin is intact in the back and waist area where the spines are located. -
-Heart and chest: Four-chamber view of the heart (large vessel exits if possible), The size, location, axis and rhythm of the heart are examined. The atria and ventricles of the heart must be the same size; Heart valves must open and close with each heartbeat. Color images are used to evaluate whether there is a hole in the heart. The aorta, the main vessel leaving the heart, and the main vessels carrying blood to the lungs are examined. The structure and shape of the rib cage, lungs and diaphragm (the membrane between the rib cage and the abdominal organs) are examined. Cystic lung lesions are excluded.
-Abdomen: Stomach, liver, intestines, kidneys and bladder and the anterior abdominal wall are examined. The stomach should be visible below the heart. The baby swallows water while in the womb and therefore the stomach appears as a black blister. It is checked whether the baby has two kidneys. The urinary bladder also appears black due to urine. The anterior abdominal wall, the area where the umbilical cord enters the baby, and the number of vessels in the cord are examined. The intestines are also evaluated with ultrasound.
- Arms and legs: They are followed from the shoulder to the hand, and the length of the arm bones and whether they appear normal are noted. Examination is performed from the hips to the feet, and it is examined whether there is symmetry in terms of long bone lengths and joint positions. The structure of the hands and feet is examined; It is investigated whether there is any number and shape abnormality. At least one hand must be "unclenched" (without a fist, fingers open) and the middle phalanx (middle bone) of the 5th finger must be visible. In babies with Down syndrome, it is seen that the middle bone in the 5th finger is missing or smaller.
- Examination of the genital area: If the family wishes, the baby can be removed. Information can be given about the gender of the patient.
Factors affecting the recognition rates of structural anomalies
Ultrasonography device
Physician's experience
Mother's weight
Baby's position
Gestational week
Type of anomaly (major/minor anomaly)
Single/multiple anomaly
The course of the anomaly in fetal life
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