In the human body structure, there is a place called the pelvis. Generally, when pregnant women are preparing to give birth in the later stages of pregnancy, doctors will help them perform pelvic external measurements to determine whether the pregnant woman can give birth to the fetus naturally. Pelvic external measurement, also known as ischial tuberosity diameter. When measuring, the examiner faces the external genitalia of the pregnant woman, touches the ischial tuberosity, and measures the distance between the inner edges of the two ischial tuberosities. So, what are the normal values measured outside the pelvis?
Methods and normal values for pelvic external measurement:
1. Iliac interspinous diameter
The pregnant woman lies supine with her legs extended on the examination bed.
⑵ Touch the anterior superior iliac spines on both sides and measure the distance between the outer edges of the anterior superior iliac spines on both sides.
The normal value is 23-26cm.
2. Interiliac crest diameter
The pregnant woman lies supine with her legs extended on the examination bed.
⑵ Measure the widest distance between the outer edges of the iliac crest on both sides.
The normal value is 25-28cm.
1. Two diameter lines can indirectly determine the length of the transverse diameter of the pelvic entrance.
3. Sacral and pubic outer diameter
(1) Pregnant women should lie on their left side, with their right leg straight and left leg bent.
⑵ is the distance from the midpoint of the pubic symphysis to the depression below the spinous process of the fifth lumbar vertebra. (Below the spinous process of the fifth lumbar spine, equivalent to the upper corner of the rhomboid fossa; or equivalent to 1-1.5cm below the midpoint of the iliac crest line on both sides.) This diameter line can indirectly infer the length of the anterior posterior diameter of the pelvic entrance and is the most important diameter line in pelvic external measurements. The outer diameter of the sacrum is related to bone thickness. Subtracting 1/2 of the radial diameter from the measured outer diameter of the sacrum is equivalent to the anterior posterior diameter of the pelvic entrance.
The normal value is 18-20cm.
4. Exit transverse diameter (ischial tuberosity diameter)
(1) Pregnant women should be in a supine position, with their legs bent and their hands tightly embracing their knees to fully bend their hip and knee joints.
The normal value is 8.5-9.5cm.
5. Sagittal diameter after export
(1) Pregnant women should be placed in a knee chest or left lateral position.
⑵ The examiner puts a finger sleeve on the index finger of the right hand and applies lubricating oil, then extends it into the anus, with the fingertip facing towards the sacrum and working together with the thumb to find the sacrococcygeal joint and mark it. If the sacrococcygeal joint is fixed, use the tip of the coccyx as a marker and measure the distance from the marker to the midpoint of the exit transverse diameter, which is the posterior sagittal diameter. If the sum of the posterior sagittal diameter and the transverse diameter of the exit is greater than 15cm, it indicates that the pelvic exit stenosis is not significant.
The normal value is 8-9cm.
The pelvis is a necessary route for fetal vaginal delivery, and postpartum exercise is also needed to restore the pelvis. Therefore, women should pay attention to pelvic health.
