station pregnancy definition
By Karen Callen, MD on October 31, 2011 in Pregnancy & Childbirth. In obstetrics, station refers to descent of the fetal presenting part (hopefully the head) in the pelvis. An imaginary line is drawn between the two bones in the pelvis (known as ischial spines). This is the âzeroâ line, and when the baby reaches this line it is considered to be in âzero station.â When the baby is above this imaginary line it is in a minus station. When the baby is below, it is in a âplusâ station. Stations are measured from -5 at the pelvic inlet to +4 at the pelvic outlet.