How do you find the obstetric conjugate?

The obstetric conjugate: Measured from the sacral promontory to the point bulging the most on the back of the symphysis pubis, located about 1 cm below its upper border. It measures 10.5 cm on average; it is the lesser anteroposterior diameter.

What is obstetric conjugate?

The distance between the sacral promontory and a point slightly below the upper inner margin of the symphysis pubis; the shortest diameter to which the fetal head must accommodate to descend successfully through the pelvic inlet.

What is the shortest diameter of the pelvic cavity?

The narrowest diameter for the fetus to pass through is the pelvic outlet, which is only 11 cm wide in the average female pelvis.

What is the shortest distance between the sacral promontory and symphysis pubis?

The anteroposterior diameter (obstetric conjugate) is the shortest distance between the sacral promontory and the pubic symphysis. The inlet usually is considered to be contracted if the obstetric conjugate is less than 10 cm or the greatest transverse diameter is less than 12 cm.

What is an obstetric pelvis?

The pelvis is made up of the two innominate bones (which occupy the front and sides) and the sacrum and coccyx (which are behind). The bones articulate through four joints. The symphysis of the pubis joins the two pubic bones. The sacrococcygeal joint attaches the sacrum to the coccyx.

What is the importance of obstetric conjugate?

n. The shortest pelvic diameter through which the fetal head must pass during birth, measured from the promontory of the sacrum to a point a few millimeters from the top of the pubic symphysis.

What are planes of obstetric pelvis?

Plane of obstetric outlet (plane of least pelvic dimensions): passes from the lower border of the symphysis pubis anteriorly, to the ischial spines laterally, to the tip of the sacrum posteriorly.

How is the true conjugate determined?

In obstetrics, the distance between the midline superior point of the sacrum and the upper margin of the symphysis pubis. It is the anteroposterior diameter of the pelvic inlet, estimated by subtracting 1.5 to 2 cm from the measurement of the diagonal conjugate.

What is external conjugate?

n. The distance in a straight line between the depression under the last spinous process of the lumbar vertebrae and the upper edge of the pubic symphysis.

How do you calculate conjugate Vera?

How big is the obstetric conjugate in centimeters?

The obstetric conjugate: Measured from the sacral promontory to the point bulging the most on the back of the symphysis pubis, located about 1 cm below its upper border. It measures 10.5 cm on average; it is the lesser anteroposterior diameter.

Which is the shortest conjugate obstetric or diagonal?

The obstetric conjugate is the shortest of the three. It extends from the sacral promontory to the thickest part of the pubic bone and measures 10 cm or more. The diagonal conjugate is the most easily and commonly assessed because it extends from the lower border of the symphysis pubis to the sacral promontory. It normally measures 11.5 cm or more.

Which is longer the pelvic inlet or the Obstetrical conjugate?

Pelvic inlet: The obstetrical conjugate is the distance between the sacral promontory and the inner pubic arch; it should measure 11.5 cm or more. The diagonal conjugate is the distance from the undersurface of the pubic arch to sacral promontory; it is 2 cm longer than the obstetrical conjugate.

Where does the diagonal conjugate start and end?

It extends from the sacral promontory to the thickest part of the pubic bone and measures 10 cm or more. The diagonal conjugate is the most easily and commonly assessed because it extends from the lower border of the symphysis pubis to the sacral promontory.