Does “major anomaly scan” refer to 4D ultrasound?
Dec 27, 2021
Source: Cainiu Health
Dr. An Na
Introduction
4D ultrasound and the “major anomaly scan” are two distinct types of prenatal examinations performed at different stages of pregnancy. The major anomaly scan primarily assesses fetal development within the maternal uterus to detect potential structural abnormalities—such as limb development, amniotic fluid volume, or umbilical cord morphology. In contrast, 4D ultrasound provides a comprehensive surface evaluation of the fetus.
The “comprehensive fetal anomaly scan” (often referred to as the “major anomaly scan”) is a prenatal screening procedure designed to detect structural fetal abnormalities early in pregnancy. In modern medicine, two-dimensional (2D), three-dimensional (3D), or four-dimensional (4D) ultrasound imaging enables clear visualization of fetal facial development and the structural development of various internal organs, thereby providing accurate, scientific evidence for the early diagnosis of congenital surface anomalies and complex congenital malformations.
Is the comprehensive fetal anomaly scan the same as a 4D ultrasound?
A 4D ultrasound and the comprehensive fetal anomaly scan are distinct types of prenatal examinations performed at different stages of pregnancy. The comprehensive fetal anomaly scan primarily assesses whether any abnormalities have developed during fetal growth within the uterus—for example, limb development, amniotic fluid volume, or umbilical cord structure. In contrast, a 4D ultrasound provides a comprehensive evaluation of fetal external anatomy, enabling detection of developmental abnormalities in various organs and facial structures. However, due to variations among fetuses—including differences in fetal position, gestational age, and image quality—not all developmental aspects can be fully assessed using either 4D ultrasound or the comprehensive anomaly scan alone.
Pregnant women should pay special attention to diet and lifestyle during pregnancy. They should maintain regular sleep-wake cycles, ensure balanced nutrition, and timely supplement calcium, zinc, and other essential trace elements. Additionally, they should balance work and rest, avoid staying up late, get adequate rest, and engage in appropriate outdoor activities—while avoiding physically demanding labor that could lead to excessive fatigue and potentially impair fetal development. Regular antenatal check-ups, as recommended by healthcare providers, are also essential.
Whether scheduling a 4D ultrasound or the comprehensive fetal anomaly scan, obstetricians typically inform expectant mothers of the scheduled examination date in advance. These scans are generally performed before 28 weeks’ gestation. Because fetal position frequently changes—and fetal movement may temporarily obscure optimal imaging—mothers may be asked to walk around briefly prior to scanning to encourage favorable positioning. Consequently, these examinations often take longer to complete. Therefore, pregnant women should schedule their appointments well in advance to avoid missing the optimal window for assessment. During the examination, mothers should remain relaxed to prevent stress-induced alterations in fetal activity, which could otherwise compromise image quality and diagnostic accuracy.
We hope the above information is helpful. Wishing you a joyful and healthy pregnancy!
