Pregnancy Ultrasonography; Detailed ultrasound, advanced ultrasound, anomaly ultrasound, second-level ultrasound, color ultrasound, large ultrasound, genetic ultrasound, 3D ultrasound, 4D ultrasound are also known terms for this scan.
This is a detailed scan performed between 18-23 weeks where each part of the fetal anatomy is examined to see if the baby is developing normally. Special attention is given to the brain, face, spine, heart, stomach, intestines, kidneys, and limbs.
Why is a Detailed Ultrasound Performed?
Most babies are normal. However, regardless of the age of the mother, there is a small chance of giving birth to a baby with structural abnormalities that can cause physical or mental limitations. Many of these abnormalities can be diagnosed and ruled out with fetal anomaly screening.
All pregnant patients should undergo detailed ultrasound (detailed ultrasound, color ultrasound, second-level ultrasound, second-stage ultrasound) at specific weeks for the early detection of certain disabilities and abnormal conditions.
Each detailed ultrasound (detailed ultrasound, color ultrasound, second-level ultrasound, second-stage ultrasound) examination involves specific examinations and measurements that need to be performed, providing valuable information about the baby’s condition in the womb.
Therefore, it is strongly recommended to perform this detailed examination at the specified weeks. Pregnancies where a detailed ultrasound (detailed ultrasound, color ultrasound, 4D ultrasound, second-level ultrasound) has not been performed are considered somewhat inadequately followed pregnancies.
18-23 Week Fetal Examination (detailed ultrasound, color ultrasound, 4D ultrasound, second-level ultrasound)
By 18-23 weeks, the baby’s organs can be seen via ultrasound. Since some structures in the brain develop by the 20th week, we prefer to perform this examination between weeks 20-22.
A detailed ultrasound (detailed ultrasound, color ultrasound, 4D ultrasound, second-level ultrasound) takes approximately 30-35 minutes.
With detailed ultrasound (detailed ultrasound, color ultrasound, 4D ultrasound, second-level ultrasound), the baby’s internal structures, such as the brain, spine, chest, heart, abdominal organs, intestines, stomach, kidneys, arms, legs, fingers, and face, can be thoroughly examined.
In this way, abnormalities such as an open spine, inward or outward turning of hands and feet, missing or extra fingers, cleft palate, or lip can be detected in advance.
The measurements are compared with growth curves for babies, and if results show that the baby is either too small or too large, further investigation is done to determine if it’s related to an illness. If no illness is found, the findings are considered personal variations also seen in healthy individuals.
Some standard images are obtained with the ultrasound machine based on international guidelines, and these images are examined for any abnormal findings.
Some findings may require further investigations, while others are considered not very important when found alone, as they can also be seen in normal babies.
The ultrasound examination method cannot detect all diseases, disorders, or abnormalities in the baby. The important thing is that your doctor conducts a valid standard examination.
Some genetic diseases can be associated with significant ultrasound findings, while the same disease may exist without showing any ultrasound signs. Therefore, it is impossible to diagnose genetic diseases with this examination method.
However, if significant findings are seen, or if several findings, which may be signs of a disease but are also found in normal babies, are present, genetic testing or procedures (amniocentesis, cordocentesis, and genetic testing) can be performed to confirm or rule out genetic diseases.
A thorough examination of the fetal heart is also conducted during this examination.
In addition to the baby, the amniotic fluid, the structure of the uterus, the condition of the cervix (whether it is shortened or opened), the location of the placenta (the baby’s lifeline), and the umbilical cord are examined.
Some findings may be significant enough to require procedures like amniocentesis or cordocentesis, even if the screening tests suggest a low probability of genetic diseases like Down syndrome.
Extended Fetal Heart Examination:
In the heart examination, features of the four chambers of the heart, the major arteries, and their exits are examined in specific standard sections.
The examination of the fetal heart is considered a high-difficulty examination because the heart is a moving organ, the fetus may not always be in the correct position for examination, and the mother’s structural characteristics (such as being overweight) may reduce the diagnostic power.
Approximately 70% of heart anomalies can be identified within the scope of this examination.
Uterine Artery Doppler Examination
The uterine arteries, which supply blood to the uterus, are located on both the right and left sides. The blood flow in these arteries is examined using “Color Doppler” and “Pulsed Doppler” methods. This gives us information about the potential for fetal growth retardation and the possibility of preeclampsia in the mother.
Can Every Anomaly Be Detected with Detailed Ultrasound?
The baby’s anatomical structures are checked with ultrasound. Functional disorders, such as whether the sensory organs are working, many muscle diseases, autism, certain mental retardation issues with no identifiable cause, some heart abnormalities that are hard to detect even after birth, speech disorders, blood diseases, and similar conditions, cannot be detected.
Even in the most equipped centers with specialists in detailed ultrasound (detailed ultrasound, color ultrasound, second-level ultrasound), not all anomalies in the baby can be detected. At most, 70% of anomalies can be identified. Some anomalies do not show detectable symptoms on ultrasound, and others develop in the months after the ultrasound is taken. On average, about 2-3% of pregnancies have congenital defects (anomalies). This rate rises to approximately 4-5% in consanguineous marriages and identical twins.
Is Detailed Ultrasound Safe?
Ultrasound has been used for monitoring pregnancies for 40 years. So far, evidence shows that ultrasound is safe for both the mother and the baby. However, we believe it is wise to scan only when there is a good reason and to use the minimum amount of sound waves based on the ALARA principle.
How Is a Detailed Ultrasound Examination Conducted?
The scan is best viewed in a dimly lit room. Since it requires a lot of concentration, especially if your baby is active, it is conducted in a quiet, dark room.
You will be asked to lie on a bed, raise your upper clothing to your chest, and expose your abdomen. The doctor will then use a handheld device called a probe, applying slight pressure on your skin to capture the images as they move it over your abdomen.
Most examinations take 30 to 40 minutes, but sometimes you may be asked to wait longer to allow your baby to move into a more suitable position.
Before taking a detailed look, the doctor will show you your baby’s heartbeat and parts of its body, such as the face and hands.
It may be difficult for you to distinguish your baby’s organs because the doctor will be viewing them from various angles and sections.
Your baby’s bones will appear white in the scan, soft tissues will look gray and speckled, and the amniotic fluid surrounding your baby will appear black.
What Can Be Seen in a Detailed Ultrasound Scan?
The most serious anomalies can be detected in a scan. However, not all problems can be seen, and some are only found after birth. Conditions like cerebral palsy and autism can never be seen in a scan.
The quality of the scan image depends on many factors, including the position of the baby and the mother’s size. For example, if the mother is overweight, it will be more challenging to see the baby clearly. A poor image will affect our ability to detect issues.
During the scan, the doctor will measure parts of your baby’s body to see how well it is growing. The doctor will measure your baby’s:
head circumference (HC)
abdominal circumference (AC)
femur or thigh bone (FL)
humerus or arm bone
Given your estimated due date, the measurements should match what is expected for your baby’s due date.
If the placenta reaches or covers the neck of your womb (your cervix), it will be identified as a low-lying placenta. If the placenta is low, you will have