What is a Detailed Fetal Anatomy (Anomaly) Scan?
The
Detailed Fetal Anatomy (Anomaly) Scan is a detailed ultrasound examination of the Fetus . Performed between
18 and 22 weeks of pregnancy, this scan is a critical part of pregnancy monitoring because it not only checks if the Fetal development is on Track but also looks for Fetal Anomalies that may impact the health of the Fetus and pregnancy.
- This comprehensive scan assesses the baby’s physical development including organs, limbs, and overall growth, and checks for structural abnormalities.
- It monitors placental health, amniotic fluid levels, and the baby’s position in the uterus.
The
Detailed Fetal Anatomy Scan is a key milestone in prenatal care. It is an essential screening tool to ensure the pregnancy is progressing normally and to identify any potential issues early.
Why Early Detection Matters:
Having a healthy baby is every parent’s greatest hope, yet in India, many parents face heartbreak due to the prevalence of birth defects and genetic disorders. Uma, a first-time mother, eagerly awaited her baby's arrival. Unaware of advanced prenatal screenings, she relied on basic check-ups at a local government hospital that lacked specialized facilities for Fetal screening. When Laxmi was born, Uma discovered she was missing limbs below her knees—a condition a detailed anatomy scan could have detected earlier. The Scan would have screened for anatomical anomalies including that of limbs. Uma was unprepared for such an outcome and didn't have the resources needed to provide a quality and meaningful life for the baby. Uma’s story echoes that of thousands of families, especially in underserved rural areas, highlighting the urgent need for accessible prenatal care.
In most cases of birth defects, complications like preterm births can be prevented, treated, or easily managed with early detection. However, the lack of awareness about prenatal screening and limited access to routine prenatal care often leave parents unprepared for the birth of a child with defects, typically discovering it too late for effective intervention.
- Early identification allows for timely medical intervention, specialist referrals, and preparation for delivery in a specialised care centre.
- Some conditions may even have prenatal treatment options, such as in-situ fetal surgery or therapies.
This scan provides critical information, ensuring the best outcomes for the baby and parents.
Importance of the Detailed Fetal Anatomy Scan for Pregnant Women:
- Detection of Structural Abnormalities:
- Identifies congenital issues such as spina bifida, heart defects, cleft lip, or abnormalities in the brain, kidneys, and limbs.
- Early detection allows for better medical care planning or surgical interventions after birth.
- Evaluation of Fetal Growth:
- Ensures the baby is growing appropriately for gestational age.
- Detects conditions like intrauterine growth restriction (IUGR) or overgrowth (macrosomia).
- Placental and Amniotic Fluid Assessment:
- Checks the placenta’s location to rule out placenta previa, a condition that may require delivery planning.
- Monitors amniotic fluid levels to ensure the baby’s environment is healthy.
- Confirmation of Baby’s Position:
- Identifies the baby’s position, helping guide further care as the pregnancy progresses.
- Opportunity for Early Interventions:
- If abnormalities are detected, parents and healthcare providers can plan appropriate treatments, specialist referrals, or even in-utero procedures where feasible.
- Parental Reassurance:
- For most pregnancies, the scan confirms normal development, providing peace of mind for parents.
What Happens During a Fetal Anatomy Scan:
During a Fetal Anatomy Scan, typically performed between 18 and 22 weeks of pregnancy, your baby’s development is closely examined by Fetal Medicine Specialists. Various parts of the baby are assessed to ensure proper growth and to check for potential issues. Here’s a quick rundown of what is focused on:
- Head and Brain: The shape and size of the skull are checked, key brain structures like the ventricles, cerebellum, and corpus callosum are examined, and signs of neural tube defects such as spina bifida are looked for.
- Face: Both eyes, the nose, and lips are checked. The cleft lip or palate is assessed, and the nasal bone is evaluated as a potential marker for certain chromosomal conditions.
- Spine: The alignment of the vertebrae is inspected, the proper closure of the spinal column (to rule out spina bifida) is ensured, and the soft tissues around the spine are examined.
- Heart: A detailed examination of the heart is conducted, including the four chambers, outflow tracts, major blood vessels, and the heart’s rhythm and rate.
- Abdomen: The abdominal wall is assessed for openings like gastroschisis or omphalocele. The presence and position of the stomach, kidneys, and bladder are confirmed.
- Limbs: The bones in the arms and legs are counted and measured, movement is checked, and the hands and feet are examined for abnormalities like clubfoot.
- Thorax and Lungs: The lungs are checked for symmetrical development, and the position and movement of the diaphragm are evaluated.
- Genitals: The external genitalia are assessed, and signs of ambiguous genitalia are checked. It is important to note that Gender identification is not allowed in India as per our PC-PNDT ACT.
- Umbilical Cord and Placenta: The cord is examined to confirm the number of blood vessels and the insertion site. The placenta’s position (like anterior, posterior, or low-lying) and amniotic fluid levels are evaluated.
- General Body: Overall growth, including head circumference and femur length, is measured. Body proportions are checked for symmetry, and movements and activity levels are monitored.
Reassurance is provided through this scan by ensuring the major organs and systems are developing properly. If anything unusual is spotted, additional testing or care is guided to ensure a healthy pregnancy journey.
What kind of anomalies can be detected during a Detailed Fetal Anatomy Scan?
The Detailed Fetal Anatomy or Anomaly Scan is a detailed ultrasound that examines the baby’s development and can identify various structural abnormalities and potential complications. Here are the different types of problems or defects that can be detected during this scan:
- Spina Bifida: Incomplete closure of the spinal column.
- Anencephaly: Absence of major portions of the brain and skull.
- Hydrocephalus: Accumulation of fluid in the brain.
2. Craniofacial Abnormalities:
- Cleft Lip and/or Palate: Openings in the lip or roof of the mouth.
- Facial abnormalities that may indicate genetic conditions.
3. Cardiac (Heart) Defects:
- Congenital Heart Defects: Structural issues like holes in the heart (septal defects) or underdeveloped chambers.
- Tetralogy of Fallot: A combination of heart defects affecting blood flow.
4. Abdominal Wall Defects:
- Gastroschisis: Intestines or other organs develop outside the baby’s body.
- Omphalocele: Abdominal organs protrude into the umbilical cord.
5. Limb Abnormalities:
- Missing, shortened, or extra limbs or digits.
- Conditions like clubfoot or abnormalities in hand or foot structure.
6. Genitourinary Abnormalities:
- Kidney Problems: Absence (renal agenesis) or improper development of kidneys.
- Bladder Issues: Enlarged bladder or inability to empty properly.
- Obstructions in the urinary tract.
7. Gastrointestinal Abnormalities:
- Diaphragmatic Hernia: A hole in the diaphragm allowing organs to move into the chest cavity.
- Atresias: Blockages in the digestive tract, such as oesophagal or intestinal atresia.
8. Chromosomal Abnormalities (Soft Markers):
- Indicators like thickened nuchal fold, absent nasal bone, or short femur length may suggest conditions like Down syndrome, Edwards syndrome, or Patau syndrome.
9. Placental and Umbilical Cord Issues:
- Placenta Previa: Placenta covering the cervix.
- Abnormal cord insertion or single umbilical artery.
10. Growth and Structural Issues:
- Intrauterine Growth Restriction (IUGR): Baby growing smaller than expected.
- Abnormalities in the fetal chest, ribs, or other structural parts.
11. Amniotic Fluid Abnormalities:
- Polyhydramnios: Excess amniotic fluid.
- Oligohydramnios: Insufficient amniotic fluid.
12. Skeletal Dysplasias:
- Abnormal bone growth or skeletal malformations.
- Conditions like dwarfism or severe skeletal defects.