How to Interpret a 4D Ultrasound Report?

The four-dimensional color Doppler ultrasound report first examines the fetal head, checking whether the outline of the fetal head is complete. Defects or deformities indicate abnormalities, while the absence of midline shift and hydrocephalus indicates normalcy. Secondly, the fetal heart is observed, and the presence of a strong heartbeat is considered normal. Thirdly, the placenta is evaluated, with a normal thickness ranging from 25 to 50 millimeters. The maturity of the placenta is classified into four grades (0, I, II, III) based on changes in the chorionic villi, placental echogenicity, and basal membrane in the four-dimensional color Doppler ultrasound report. Grade III placenta can be used as a reference for fetal maturity. Fourthly, the umbilical cord is observed, and normally, it should float in the amniotic fluid. Fifthly, the femur length, which represents the length of the fetal thigh bone, is measured. Its normal value should be less than 20 to 30 millimeters difference from the biparietal diameter value corresponding to the gestational age. Sixthly, the amniotic fluid is evaluated, and a depth of 3 to 7 centimeters is considered normal.

The optimal timing for four-dimensional color Doppler ultrasound varies from individual to individual and depends on the specific needs. Generally, the best time for this examination is during the 5-8 (20-28 weeks) months of pregnancy, when the fetal limbs and major organs have fully developed, and the amniotic fluid is suitable for screening for fetal anomalies. If the intention is to capture a full-body image of the fetus, the earlier stages of pregnancy may be chosen. However, it is important to note that performing four-dimensional color Doppler ultrasound during the first 1-2 months is generally not recommended, as there is significant controversy surrounding its appropriateness during this period. For the detection of external fetal defects, the mid-to-late stages of pregnancy are more suitable for four-dimensional color Doppler ultrasound.

Four-dimensional color Doppler ultrasound can determine fetal age, analyze fetal development, localize the placenta, detect fetal abnormalities, and provide a multi-directional and multi-angle observation of fetal growth and development. It provides scientific evidence for the early diagnosis of fetal congenital surface malformations and congenital heart diseases. This technique can diagnose diseases and symptoms such as cleft lip and palate, anencephaly, hydrocephalus, and microcephaly. For pregnant women, it can also reveal conditions such as excessive or insufficient amniotic fluid. However, it is not a panacea, and some diseases, such as neonatal hearing loss and cataracts, may not be detectable using this method.