the diameter of the fetal head between the two parietal eminences.
bi·pa·ri·e·tal di·am·e·ter
(bī'pă-rī'ĕ-tăl dī-am'ĕ-tĕr) The diameter of the fetal head between the two parietal eminences.
biparietal diameter
Abbreviation: BPD The transverse distance between the parietal eminences on each side of the head (about 9.25 cm).See also: diameterAcronymsSeeBPDThesaurusSeediameter