Pregnant female friends are generally more concerned about the value of fetal umbilical blood flow, because both high and low values have a very serious impact on the fetus, and umbilical blood flow is related to the pregnancy cycle, and its value is also different. If there is an abnormally high value of umbilical blood flow during different stages of pregnancy, it may cause serious consequences for the fetus. What is the normal value of umbilical blood flow in a 32 week fetus?
The normal value of umbilical blood flow is 3 and 5 at 24 weeks, with an upper limit of 4 and 25. Exceeding this value is considered abnormal. The pulsatility index (PI) is 1, 12 ± 0, 17, and the resistance index (RI) is 0, 66 ± 0, 07. After 30 weeks of pregnancy, when the umbilical artery's SV/DV3 is 0, PI1、7,RI0、 Fetal intrauterine distress occurs around 7 o'clock. The peak systolic (A or S) and trough diastolic (B or D) values of arterial blood flow can be calculated to determine the S/D or A/B ratio, as well as the resistance index (RI=A-B/A) and pulsatility index (PI=A-B/mean A, B). During normal pregnancy, these values decrease with gestational age, typically A/B4 before 24 weeks, A/B less than 3.0 after 30 weeks, and RI less than 0.68
The ratio of the maximum systolic blood flow velocity (S) to the end diastolic blood flow velocity (D) of the umbilical artery (S/D, A/B), and the dynamic changes in the S/D (A/B) ratio can be observed to determine the development of the placenta. Under normal circumstances, as the fetus develops, the placenta gradually enlarges, vascular resistance gradually decreases, and the S/D (A/B) ratio gradually decreases. The S/D ratio almost linearly decreased from 2 and 8 to 2 and 2 from 25 to 41 weeks of pregnancy. Fetal intrauterine growth retardation, placental and fetal dysplasia, no enlargement of placenta, and no decrease in vascular resistance. Therefore, the S/D ratio does not decrease. In clinical practice, if the S/D ratio does not decrease regularly or instead increases, it indicates poor fetal development.
During normal pregnancy, the S/a ratio of the venous catheter decreases with increasing gestational age, from around 3 at 14 weeks to around 2 at 42 weeks. The S/a ratio of the venous catheter is associated with fetal hypoxemia.
The above is a detailed description of the normal value of umbilical blood flow in a 32 week fetus. Umbilical blood flow, in other words, is a channel for delivering oxygen to the fetus. Generally, as the gestational age increases, its value will gradually decrease. If any abnormalities occur, please seek medical attention promptly. Otherwise, prolonged exposure may lead to fetal hypoxia in the uterus, ultimately resulting in irreparable regrets.