The B-ultrasound examination in mid pregnancy can understand the development of the fetus, observe the development status of various organs and the size of the fetus, and rule out fetal abnormalities. However, the dense numbers on the B-ultrasound sheet can cause headaches for many pregnant women. Today, let's learn together what is the normal range of NB values in mid pregnancy B-ultrasound?
In ultrasound examination, nb refers to the nasal bone of the fetus. The fetal nasal bone is usually measured from 11 weeks to 13+6 weeks of pregnancy. The normal range of fetal development NB is as follows:
The average value from 11 weeks of pregnancy to 11+6 weeks of pregnancy is 2.5mm
The average value from 12 weeks of pregnancy to 12+6 weeks of pregnancy is 3.0mm
The average value from gestational weeks 13 to 14 is 3.3mm
The average value from 15 weeks to 17 weeks of pregnancy is 4.0mm
The average value from 18 weeks to 20 weeks of pregnancy is 4.5mm
The average value from 21 weeks to 24 weeks of pregnancy is 5.0mm
During prenatal ultrasound examination, the standard normal nasal display of the fetus is three clear lines: the upper line represents the skin, the thicker and more echogenic line below represents the nasal bone, and the third line represents the nasal tip, which is almost connected to the skin but slightly higher. When ultrasound is used to examine the nasal bone of a fetus, it will be enlarged to only display the fetal head and upper chest area. The fetal nasal bone will be displayed horizontally, and the probe beam will be perpendicular to the nasal bone at an angle of about 45 ° to the fetal facial axis, and then the average value will be taken.
