Normal values ​​for external pelvic measurements

There is a structure on both sides of the hip bone called the pelvis. The shape of each person's pelvis is different, but the pelvis has a specific normal value. If it is larger than this normal value, bone deformation will occur. If the distance between the bone tuberosities is large, it will be difficult for women to become pregnant. However, this distance can be adjusted through massage. During the massage process, pay attention to the method and strength. If you persist for a long time, you will see certain results.

Also known as the ischial tuberosity diameter. When measuring, the examiner faces the pregnant woman's vulva, touches the ischial tuberosities, and measures the distance between the inner edges of the two ischial tuberosities. If there is no pelvic measuring device, the examiner's fist can be placed between the two ischial tuberosities. If it can accommodate a fist, the estimated diameter is greater than 8.5cm, which is normal. By measuring this diameter, we can directly understand the transverse diameter length of the pelvic outlet. When the transverse diameter of the outlet is less than 8 cm, the posterior sagittal diameter should be measured.

Explain the purpose of the operation to the pregnant woman to gain her cooperation.

1. Anterior superior iliac spine

⑴ Assist the pregnant woman to lie on her back with her legs stretched out on the examination bed.

⑵ Clearly palpate the anterior superior iliac spines on both sides and measure the distance between the lateral edges of the anterior superior iliac spines on both sides.

⑶ Check the data and record it. The normal value is 23 to 26 cm.

2. Iliac crest diameter

⑴ Assist the pregnant woman to lie on her back with her legs stretched out on the examination bed.

⑵Measure the widest distance between the outer edges of the iliac crests on both sides.

⑶ Check the data and record it. The normal value is 25 to 28 cm.

The two diameter lines 1 and 2 can indirectly understand the transverse diameter length of the pelvic inlet.

3. Sacropubic external diameter

⑴ Assist the pregnant woman to lie on her left side with her right leg straight and her left leg bent.

⑵ is the distance from the midpoint of the upper edge of the pubic symphysis to the depression below the spinous process of the fifth lumbar vertebra. (Below the spinous process of the fifth lumbar vertebra, equivalent to the upper corner of the rhomboid fossa; or equivalent to 1~1.5cm below the midpoint of the line connecting the iliac crests on both sides.) This diameter can indirectly infer the anteroposterior diameter of the pelvic inlet and is the most important diameter in external pelvic measurement. The sacropubic external diameter is related to the thickness of the bone. The measured sacropubic external diameter minus 1/2 of the radial ulna circumference is equivalent to the anterior-posterior diameter of the pelvic inlet.