How to measure the abdominal circumference of pregnant women?

Pregnant women actually need to measure their abdominal circumference at every time period. This can indirectly estimate the weight of the child and see how the child is developing. The general measurement method is once every four weeks. In the later stages, it is necessary to measure every two weeks. This way you can always pay attention to the child's development, and you must also do regular prenatal check-ups.

Why do we need to measure uterine height and abdominal circumference?

The height of the pregnant mother's uterus and abdominal circumference are closely related to the size of the fetus. During the early and mid-pregnancy, there is a certain standard for monthly growth. It is necessary to know the length of each gestational week. In the later stages, by measuring the uterine height and abdominal circumference, the weight of the fetus can also be estimated. Therefore, during every prenatal check-up, the uterine height and abdominal circumference should be measured to estimate the intrauterine development of the fetus. At the same time, the uterine height pregnancy chart can be used to understand the intrauterine development of the fetus and whether it is developmentally delayed or macrosomia.

The enlargement of the uterus during pregnancy is regular, manifested as an increase in the base and abdominal circumference. Generally, it is measured once every 4 weeks starting from the 20th week of pregnancy, once every 2 weeks from the 28th to 35th week of pregnancy, and once a week after the 36th week of pregnancy.

How to measure uterine height and abdominal circumference

Method for measuring uterine height: Let the pregnant woman lie flat on the bed after urinating, and use a soft tape measure to measure the distance from the midpoint of the upper edge of the pubic symphysis to the fundus of the uterus. Generally, measurements should be taken every 4 weeks starting from the 20th week of pregnancy; every 2 weeks from the 28th to 35th week of pregnancy; and once a week after the 36th week of pregnancy.

The measurement results are plotted on a pregnancy chart to see whether the fetal development is consistent with the gestational age. When measuring the height of the uterine fundus, if it is found to be inconsistent with the gestational age, or too large or too small, the cause should be found. Such as B-ultrasound and other special examinations to check for twins, deformities, stillbirths, too much or too little amniotic fluid, etc.

How to measure abdominal circumference: Measure the length from the navel to the waist and abdomen. When measuring, make sure the lower part of the tape measure is completely close to the body, but do not tighten the abdomen.

How to calculate fetal weight using uterine height and abdominal circumference

1. Fetal weight (g) = -2686.60 + 171.48 × abdominal circumference;

2. Fetal weight (g) = 2900 + 0.3 × uterine fundus height × waist circumference;

3. Fetal weight (g) = -5168.32 + 100.97×head circumference + 110.86×abdominal circumference + 143.09×femur length + 331.43×fetal leg subcutaneous fat thickness;

The above method is an estimate and does not represent the actual weight of the baby at birth. The purpose of predicting fetal weight is to detect problems in fetal development as early as possible. Generally speaking, there will be a plus or minus 10%-15% error between the actual weight at birth and the predicted weight. For example, if the birth weight is 4000 grams, the error range will be 400 grams. In other words, the heavier the baby, the greater the margin of error.

Understand the transverse diameter of the uterus and the corresponding height of the uterine fundus in order to understand the situation inside the cavity and whether the size of the uterus is consistent with the gestational age.