What is the normal biparietal diameter at 38 weeks of pregnancy?

If the fetus develops normally and the menstrual cycle is regular, the biparietal diameter of the fetus should be above 9 cm at 38 weeks of pregnancy. It may vary due to the physical condition of the pregnant woman and the development of the fetus, but the difference will not be very large. If the difference is large, it should be taken seriously and certain examinations should be carried out to determine why the fetus has not reached the normal range.

If the menstrual cycle is normal and the gestational age is consistent with the month of amenorrhea, the biparietal diameter at 38 weeks of pregnancy is approximately 9.08 ± 0.59CM. The average value of abdominal circumference at 38 weeks of pregnancy is: 30.63±2.83" and the average value of femur length is 7.20±0.43.

Also known as BPD, doctors often use it to observe children's development and various measurement data. The measurement data of the child. Determine whether there is cephalopelvic disproportion and a smooth delivery. It should reach 9.3 cm or more at full term. According to general rules, after 5 months of pregnancy, the BPD is basically consistent with the month of pregnancy, that is, at 28 weeks of pregnancy (7 months) the BPD is about 7.0 cm, at 32 weeks of pregnancy (8 months) it is about 8.0 cm, and so on. After 8 months of pregnancy, an average weekly growth of about 0.2 cm is normal. When the due date cannot be determined by CRL in the early stage, BPD is often used to predict it; after the middle stage, this data is often also needed to be measured when estimating the fetal weight.

The biparietal diameter of the fetus is used to determine whether the child's development and size are normal. It is also a criterion for measuring whether a natural birth can be achieved, because it is the largest diameter of the fetus's entire body. Generally, the biparietal diameter of a full-term fetus should be above 90mm. Therefore, the size of the pregnant woman's pelvis and the size of the fetus must be considered to determine whether a natural birth or a caesarean section is required.