During pregnancy, women need to undergo multiple examinations, such as B-ultrasound and Tang screening, which are very important examination items. When you receive the ultrasound examination form, you will see that one of the items is S/D, which refers to the fetal umbilical artery blood flow. So, what is the S/D standard for a 32 week fetus?
At 32 weeks of pregnancy, the standard for S/D is 2.0-3.0 for women. The S/D value of fetal umbilical artery blood flow can reflect the peripheral vascular resistance of the fetus. If the index is high, it indicates that the distal vascular bed resistance is high, which will reduce blood flow and be detrimental to the normal development of the fetus. If the index is relatively low, it indicates low distal vascular resistance and high blood flow.
The S/D value of fetal umbilical artery blood flow can also reflect the hemodynamic situation of the fetal placenta, allowing doctors to understand the ratio of fetal umbilical artery systolic pressure to diastolic pressure. The high or low S/D value is related to fetal blood supply, and it is easy to cause abnormal S/D values in cases of placental dysfunction or umbilical cord abnormalities.
Under normal fetal conditions, as the duration of pregnancy increases, the S value tends to decrease while the D value increases. Throughout the entire pregnancy, the S/D value remains below 3. If the S/D value exceeds 3 during the examination, it is considered an abnormal situation and it is necessary to seek medical help in a timely manner, identify the cause as soon as possible, and actively seek treatment.
