station

station /stā″shən/ [L, stare, to stand] , the level of the biparietal plane of the fetal head relative to the level of the ischial spines of the maternal pelvis. An imaginary plane at the level of the spines is designated “zero station.” Higher and lower stations are numbered at intervals of 1 cm and labeled as minus above and plus below. For example, “station minus three” is 3 cm above the spines, and “station plus two” is 2 cm below the spines. In breech presentation, the bitrochanteric diameter of the breech is used to determine station. See also dilation, effacement, labor.