The anatomy scan, often called the Level II ultrasound or 20-week scan, is a significant milestone during the second trimester of pregnancy. This detailed imaging procedure is typically scheduled between 18 and 22 weeks of gestation. It provides a comprehensive view of the developing fetus, allowing healthcare providers to assess growth and development.
Eating and Drinking Before Your Scan
Unlike some medical procedures, fasting is generally not required before an anatomy scan. Eating a small, normal meal is often advised to ensure comfort during the procedure, which can take anywhere from 45 minutes to an hour or more. Providers often suggest eating something light and familiar rather than skipping a meal entirely.
The primary consideration with food and drink is how it affects the fetal activity level. While some providers suggest consuming a small amount of juice or a light snack shortly before the appointment to encourage movement, consuming excessive sugar or caffeine should be avoided. Hyperactive fetal movement can make it difficult for the sonographer to obtain the precise, still measurements required for the detailed anatomical survey.
If the fetus is moving too much, capturing clear images of structures like the four chambers of the heart or specific brain structures becomes challenging and may prolong the appointment. Always confirm the exact protocol with the specific facility where your scan is scheduled, as instructions can vary slightly between clinics.
Other Key Preparation Instructions
Other preparations focus on logistical ease and optimizing image clarity. Many facilities ask patients to arrive with a full or partially full bladder, especially if the scan is performed on the earlier side of the 18 to 22-week window. A full bladder helps push the uterus slightly higher into the abdomen, improving the visibility of the fetus and the cervix.
Always confirm the exact bladder requirement, as some practices prefer you to empty your bladder before the longer 20-week scan for comfort. Wearing comfortable, loose-fitting clothes is recommended, ideally a two-piece outfit that allows easy access to the abdomen. The sonographer applies ultrasound gel and moves the transducer freely across the skin to capture the necessary views.
The Purpose of the Anatomy Scan
The detailed anatomy scan provides a systematic survey of the fetus, confirming that development is progressing as expected. A major component is biometry, which involves measuring specific fetal parts, such as the head circumference, abdominal circumference, and femur length, to estimate the growth rate and confirm the gestational age. These measurements are then plotted against growth charts.
The sonographer meticulously examines all major internal organs and structures. This includes checking the proper formation of the four chambers of the heart and great vessels, assessing the symmetry and structure of the brain, and confirming the presence of the stomach, kidneys, and bladder. Clear views of the fetal spine, limbs, hands, and feet are also obtained to check for structural integrity.
The sonographer also assesses the surrounding environment. This includes checking the location of the placenta for conditions like placenta previa and measuring the volume of amniotic fluid. This comprehensive assessment ensures that all structures are developing appropriately and that the fetus is in a healthy environment.