38 weeks fetal amniotic fluid standard

The presence of amniotic fluid can create a healthy growth environment for the fetus, and amniotic fluid is also an important medium for supplementing fetal nutrition. More importantly, when a pregnant woman's belly is hit by external force, the amniotic fluid can effectively buffer the force of the external impact to a great extent. The amount of amniotic fluid in the pregnant woman's belly varies during each pregnancy. So what is the normal value of amniotic fluid in the belly of a pregnant woman at 38 weeks of pregnancy?

Standard value of amniotic fluid in 38 weeks of pregnancy

The amount of amniotic fluid increases with the duration of pregnancy. It is about 5-10 ml at 8 weeks of pregnancy, about 30 ml at 10 weeks of pregnancy, about 400 ml at 20 weeks of pregnancy, and about 1000 ml at 38 weeks of pregnancy. Thereafter, the amount of amniotic fluid gradually decreases. At 40 weeks of pregnancy, the amount of amniotic fluid is about 800 ml. In case of overdue pregnancy, the amount of amniotic fluid decreases significantly and can be reduced to less than 300 ml.

The "amniotic fluid index method" is to divide the uterus into 4 quadrants, measure the maximum depth of the amniotic fluid in each quadrant, and then add up the total. A total value within the range of 8 to 18 cm is normal, less than 8 cm is too little amniotic fluid, and greater than 18 cm is too much amniotic fluid.

The uterus is divided into four quadrants at right angles using the umbilical horizontal line and the linea alba as markers. The vertical diameter of the largest amniotic fluid pool in each quadrant is measured, and the sum of the four is the amniotic fluid index. The normal value range is: 8 to 24 cm. Abbreviation: AFI)

The most common causes of oligohydramnios include ruptured membranes, placental problems, and disease factors. Oligohydramnios is most common during the last stages of pregnancy, especially after the due date. The later the oligohydramnios condition occurs, the less impact the fetus will have.

Causes of low amniotic fluid

1. In case of overdue pregnancy, the placenta functions poorly, the perfusion is insufficient, the fetus becomes dehydrated, and the amount of amniotic fluid is low. Some scholars also believe that in overdue pregnancy, the fetus is overmature, its renal tubules are more sensitive to antidiuretic hormone, and the low urine volume leads to oligohydramnios. The incidence of oligohydramnios caused by post-term pregnancy is as high as 20%-30%.

2. Fetal malformations, such as congenital renal agenesis, renal hypoplasia, ureteral or urethral stenosis, etc., lead to oliguria or anuria and cause oligohydramnios.

3. Intrauterine growth retardation (IUGR) Oligohydramnios is one of the characteristics of intrauterine growth retardation. Chronic hypoxia causes redistribution of fetal blood circulation, mainly supplying the brain and heart, while renal blood flow decreases and fetal urine production decreases, resulting in oligohydramnios.

Through the above, you can understand the standard value of fetal amniotic fluid at 38 weeks of pregnancy, and you can check it by yourself on the examination report. In fact, in the late stages of pregnancy, the closer you get to delivery, the less amniotic fluid there is, which is a normal phenomenon. There is no need to rush to replenish it. You can induce labor or prepare for delivery according to the doctor's advice. Let’s look forward to the arrival of the baby together.