sacrotransverse (ST) position

sa·cro·trans·verse (ST) po·si·tion

(sā'krō-trans-vĕrs' pŏ-zish'ŏn) A breech presentation of the fetus with its sacrum pointing to the right (right sacrotransverse, RST) or to the left (left sacrotransverse, LST) sacroiliac articulation of the mother.