A growth scan is an ultrasound examination performed during pregnancy to monitor the baby’s development. It offers valuable insights into how the baby is growing inside the womb, providing information about its size and overall well-being.
What is a Growth Scan?
A growth scan is a specialized ultrasound procedure designed to assess a baby’s size, growth rate, and health during pregnancy. Unlike routine screening ultrasounds, this scan focuses on biometric measurements to track fetal development. It uses high-frequency sound waves, harmless to both mother and baby, to create real-time images of the fetus.
These sound waves bounce off the baby’s structures and are converted into visual images on a screen. The scan’s objective is to evaluate how consistently the baby is growing over time. While the routine anatomy scan around 20 weeks surveys the baby’s physical structures, the growth scan specifically targets the progression of the baby’s size.
Why You Might Need One
Healthcare providers may recommend a growth scan for several reasons. One common indication is when the mother’s fundal height measurement suggests the baby is smaller or larger than anticipated for gestational age. This indicates a need for a more precise assessment of fetal size.
Concerns about the baby’s growth rate can also prompt a growth scan. For instance, if there is a suspicion of restricted or excessive growth, an ultrasound can provide detailed measurements. Maternal health conditions, such as gestational diabetes or high blood pressure, often necessitate growth scans to monitor their impact on fetal development.
Expectant parents carrying multiple babies, like twins or triplets, typically undergo more frequent growth scans to track each baby’s individual development. A history of growth issues in previous pregnancies can also lead a healthcare provider to recommend a growth scan.
During the Scan
The growth scan procedure is non-invasive and generally comfortable, similar to other prenatal ultrasounds. The expectant parent will lie on an examination table, and a clear, water-based gel will be applied to their abdomen. This gel helps the ultrasound transducer, a small handheld device, make proper contact with the skin and transmit sound waves effectively.
The sonographer or healthcare provider will gently move the transducer across the abdomen, capturing images of the baby. Specific measurements are taken to estimate the baby’s size and growth. Key measurements include the head circumference (HC), which assesses head size, and the abdominal circumference (AC), which reflects the baby’s nutritional status.
Another measurement is the femur length (FL), providing an estimate of the baby’s bone growth. These measurements are combined to calculate an estimated fetal weight (EFW), assessing the baby’s overall size. The sonographer may also assess the amount of amniotic fluid and confirm the placenta’s position. Ultrasound technology is considered safe for both mother and baby, as it does not use ionizing radiation.
Interpreting the Findings
After the measurements are taken during a growth scan, they are compared to standard growth charts, which represent the typical range of sizes for babies at different gestational ages. The results are expressed as a percentile, indicating how the baby’s measurements compare to others at the same stage of pregnancy. For instance, a baby measuring at the 50th percentile is considered to be of average size.
If a baby’s measurements fall below the 10th percentile, it might suggest the baby is smaller than expected, possibly indicating fetal growth restriction. Conversely, measurements above the 90th percentile could suggest the baby is larger than average, sometimes associated with conditions like gestational diabetes. A single scan provides a snapshot in time; healthcare providers often look at trends over several scans to gain a more complete picture of the baby’s growth pattern.
If the findings from a growth scan raise concerns, additional monitoring or further investigations might be recommended. This could involve more frequent follow-up scans to track growth progression or referral to a specialist for a more in-depth evaluation.