A growth scan during pregnancy is a medical imaging procedure that assesses a baby’s development and well-being. While not every pregnant individual receives a 32-week growth scan routinely, it is a common and valuable part of prenatal care for many. This type of ultrasound helps healthcare providers gather important information about the baby’s growth trajectory and overall health as the pregnancy progresses into the third trimester.
When a 32-Week Growth Scan Is Recommended
A 32-week growth scan is frequently recommended in various situations, even though it is not universally routine for all pregnancies. One common reason for this scan is if there are concerns about the baby’s growth, such as when the fundal height measurement (the distance from the pubic bone to the top of the uterus) is consistently larger or smaller than expected. This can indicate a need for further investigation into the baby’s development.
Certain maternal medical conditions also often lead to a recommendation for a 32-week growth scan. These conditions include gestational diabetes, pre-existing diabetes, high blood pressure, kidney disease, or autoimmune disorders, all of which can potentially influence fetal growth and well-being. A history of complications in previous pregnancies, such as growth restriction, preterm birth, or stillbirth, also prompts healthcare providers to recommend additional monitoring.
For individuals carrying multiple babies, such as twins or triplets, growth scans are typically recommended more frequently to monitor each baby’s individual growth and development. Concerns about the placenta’s function or position, including conditions like placenta previa where the placenta covers the cervix, can also necessitate a growth scan to assess its impact on the baby’s growth. Some practitioners might also suggest a 32-week scan for pregnancies conceived through assisted reproductive technologies (ART) due to specific considerations. If earlier scans revealed any findings or concerns, a 32-week growth scan provides an opportunity for follow-up and further assessment. An advanced maternal age can sometimes be another factor influencing the recommendation for a growth scan.
What to Expect During Your Scan
A 32-week growth scan is performed using ultrasound technology, which is a non-invasive and generally painless procedure. It typically involves a transabdominal approach, where a sonographer moves a transducer device over the pregnant individual’s abdomen. This device uses high-frequency sound waves to create images of the baby and surrounding structures inside the womb.
During the scan, the sonographer will take several specific measurements to assess the baby’s growth. These measurements include the biparietal diameter (BPD), the width of the baby’s head, and the head circumference (HC), measuring the distance around the baby’s head. The abdominal circumference (AC), a measurement around the baby’s abdomen, is also taken and is often considered a sensitive indicator of growth. Another key measurement is the femur length (FL), the length of the baby’s thigh bone.
From these measurements, an estimated fetal weight (EFW) is calculated, providing an approximation of the baby’s size. The scan also assesses the amniotic fluid volume, ensuring there are adequate fluid levels surrounding the baby. The sonographer will also check the placenta’s location and appearance to evaluate its health and function. The entire growth scan typically takes approximately 20 to 30 minutes, though it can sometimes take longer depending on the baby’s position or if additional assessments are needed.
Interpreting Your Growth Scan Results
After the growth scan, the measurements taken are compared against standard growth charts for gestational age. These comparisons are often expressed as percentiles, which indicate how your baby’s measurements compare to other babies at the same stage of development. For instance, if a measurement falls on the 50th percentile, it means the baby’s size is average for its gestational age. Most healthcare providers consider measurements between the 10th and 90th percentile to be within the expected range for growth.
If the baby’s estimated fetal weight or abdominal circumference is below the 10th percentile, it may be classified as small for gestational age (SGA) or potentially fetal growth restriction (FGR). This means the baby is smaller than expected, and further monitoring, repeat scans, or specialized blood flow studies (Doppler studies) might be recommended to investigate the cause and ensure the baby’s well-being.
Conversely, if the baby’s estimated fetal weight is above the 90th percentile, it may be classified as large for gestational age (LGA) or macrosomia. This can sometimes be associated with conditions like gestational diabetes, and further tests, such as a glucose tolerance test, might be suggested if not already performed. Variations in amniotic fluid volume, such as too much (polyhydramnios) or too little (oligohydramnios), can also be detected during the scan. These findings may also warrant additional follow-up. Healthcare providers will discuss the results in detail and provide personalized advice and follow-up based on the overall clinical picture.