How low can the umbilical artery SD be?

During pregnancy, a pregnant woman will go to the hospital for regular prenatal checkups for the sake of the baby's health. Prenatal checkups can also detect in time whether the baby has any disease while in the mother's belly. There are two very important arteries around the baby, namely the umbilical arteries. Some pregnant women will specifically check the SD value of the umbilical artery during prenatal check-ups. So how low can the umbilical artery SD value be?

The harm of low umbilical artery SD value

If the child has the umbilical cord wrapped around the neck and has high vascular resistance, you can go to the obstetrics department for a check-up. Some vasodilator drugs can be used. If there are no other symptoms, you can also observe. Generally speaking, if the baby is lacking oxygen, the fetal heart rate will be abnormal, either greater than 160 beats/minute or less than 120 beats/minute. If you have been pregnant for more than 5 months, normal fetal movements are generally 3-5 times per hour. In the case of hypoxia, the fetus is restless in the early stage of hypoxia, which is manifested by a significant increase in fetal movements. When the hypoxia is severe, the fetal movements decrease, weaken, or even disappear. After the fetal movements disappear, the fetal heart rate generally disappears within 24 to 48 hours.

What is the normal umbilical artery SD value?

The S/D value of umbilical cord blood flow gradually decreased from 2.96±0.68 to 2.22±0.33 at 39 weeks of pregnancy, with an average decrease of 0.067 per week. It can also be seen from the standard deviation of the variation between the groups that with the increase of gestational weeks, the range of variation becomes smaller, indicating that the fetal circulatory system tends to mature and the umbilical artery resistance tends to be stable. In clinical work, the average value cannot be used as normal.

It is very important to define normal and abnormal values. The main basis for its determination is a large amount of statistical processing combined with a comprehensive judgment based on the incidence of clinical pathological pregnancy. If the cut-off value is too high, not all abnormal cases can be screened out; if the cut-off value is too low, the diagnosis of abnormal cases will be expanded, resulting in misdiagnosis, incorrect treatment and excessive tension for pregnant women.

If the umbilical artery SD value is low, it will cause great harm to both the mother and the baby. The low umbilical artery SD value is caused by insufficient oxygen in the mother's stomach. If you do not seek medical attention in time, it may have a very serious impact on the baby. If the umbilical artery SD value is low, mothers must not be too nervous and can choose oxygen inhalation to regulate.