Extra-pelvic measurements are used to assess the size and shape of the pelvis and to determine whether the fetus can be delivered vaginally. During the measurement, the examiner faces the genital area of ​​the pregnant woman, touches the ischial tuberosity, and measures the distance between the inner edges of the two ischial tuberosity. If there is no pelvic measuring device, the inspector's fist can be placed between the two ischial nodules. When a punch is allowed, it is estimated that the diameter is greater than 8.5cm, which is normal. Measure this diameter line to directly understand the length of the pelvic outlet transverse diameter. When the transverse diameter of the outlet is less than 8 cm, the posterior sagittal diameter should be measured.

Basic Information

Specialist classification: maternity check check classification: physical examination

Applicable gender: whether women are fasting: not fasting

Analysis results:

Below normal:
Tips may be limited in development.

Normal value:
Interpupillary diameter: 23-26cm
Inter-turn diameter: 25-28cm
Shame outer diameter: 18-20cm
Exit transverse diameter: 8.5-9.5cm

Above normal:
If no other symptoms are normal.

negative:

Positive:

Tips: Check your relaxation, you should face it positively and actively cooperate with the inspection. The movement should be gentle. Keep warm and cover the patient. Normal value

1. The normal value of the interspinous diameter is 23 to 26 cm.

2. The normal value of the intercondylar diameter is 25 to 28 cm.

3, the normal value of the shame outer diameter is 18 ~ 20cm.

4. The normal value of the exit transverse diameter is 8.5 to 9.5 cm.

5, the normal value of the pubic arch angle is 90 °.

Clinical significance

Abnormal results:

1. The diameter of the spurs is not in the range of 23 to 26 cm.

2. The inter-turn diameter is not in the range of 25 to 28 cm.

3. The outer diameter of the shame is not in the range of 18 to 20 cm.

4. The exit transverse diameter is not in the range of 8.5 to 9.5 cm.

5. The pubic arch angle is greater than or less than 90°.

According to the results and the physical condition of the pregnant woman, it is concluded that vaginal delivery is not possible

Need to check the crowd: pregnant women and pregnant women with a history of dystocia.

The result is low, may be a disease: a large fetus, bone birth canal abnormal dystocia

Taboo before inspection: no special contraindications.

Requirements for inspection: Check the feelings of relaxation, should face positively, and actively cooperate with the inspection. The movement should be gentle. Keep warm and cover the patient.

Inspection process

Explain the purpose of the operation to pregnant women in order to obtain cooperation.

1, the spurs

(1) Assisting the pregnant woman to lie on the examination bed.

(2) Touch the anterior superior iliac spine on both sides and measure the distance between the lateral edges of the superior anterior superior iliac spine on both sides.

2, the diameter of the road

(1) The pregnant woman lying on the examination bed.

(2) Measure the widest distance between the outer edges of the two sides.

3, shame outer diameter

(1) Assist the pregnant woman to take the left lateral position, the right leg is straight, and the left leg is flexed.

(2) is the distance from the midpoint of the pubic symphysis to the depression of the fifth lumbar spine. The fifth lumbar spine is equivalent to the upper corner of the diamond nest; or equivalent to 1~1.5cm below the midpoint of the bilateral collateral. This line can indirectly predict the length of the anterior and posterior diameter of the pelvic inlet, which is the most important diameter in the measurement outside the pelvis.

4, the exit transverse diameter (ischial nodular diameter)

(1) Assisting the pregnant woman in a supine position, bending her hands and holding her knees.

(2) Also known as the ischial tuberosity. During the measurement, the examiner faces the genital area of ​​the pregnant woman, touches the ischial tuberosity, and measures the distance between the inner edges of the two ischial tuberosity. If there is no pelvic measuring device, the inspector's fist can be placed between the two ischial nodules. When a punch is allowed, it is estimated that the diameter is greater than 8.5cm, which is normal. Measure this diameter line to directly understand the length of the pelvic outlet transverse diameter. When the transverse diameter of the outlet is less than 8 cm, the posterior sagittal diameter should be measured. At this time, the pregnant woman takes the knee or the left side of the position. The right index finger of the examiner wears the finger sleeve and applies the lubricating oil, and then extends into the anus. The fingertips cooperate with the thumb to find the appendix joint and mark it. If the appendix joint is fixed, the tip of the tailbone is marked, and the distance from the mark to the midpoint of the transverse diameter of the outlet is measured, which is the posterior sagittal diameter. If the sum of the posterior sagittal diameter and the exit transverse diameter is greater than 15 cm, the exit can pass through the normal term fetus.

5, pubic arch angle

1) Assist pregnant women in supine position and bend their legs. Hold your hands on your knees.

2) Use the left and right thumb tips to slant and close together, and place them on the lower edge of the pubic symphysis. The left and right thumbs are placed flat on the pubic bone.

3) Assist pregnant women to organize their underwear, organize the objects, and put them back in place.

Not suitable for the crowd

There are no special taboos.

Adverse reactions and risks

Nothing.