obstetric conjugate diameter -->
obstetric conjugate
medical dictionary

The diameter that represents the shortest diameter through which the head must pass in descending into the superior strait and measures, by means of X-ray, the distance from the promontory of the sacrum to a point on the inner surface of the symphysis a few millimetres below its upper margin.

Synonyms: obstetric conjugate diameter.

(05 Mar 2000)