When a fetus is at +1 station during labor, where is the presenting part located?

When a fetus is at +1 station during labor, it indicates that the presenting part of the fetus is located one centimeter below the ischial spines of the pelvis. The station system is a way of measuring the position of the fetus in relation to the ischial spines, which are bony landmarks in the pelvis that serve as reference points.

In obstetrics, the ischial spines are considered the zero station. Positions above the ischial spines are negative stations (e.g., -1, -2), indicating that the fetus is higher in the pelvic cavity. A positive station, such as +1, indicates descent, meaning the fetus is moving down through the pelvic inlet towards the birth canal.

Therefore, being at +1 means the presenting part is in a favorable position to proceed through the birth canal, closer to birth. This is a crucial stage during labor, as it signifies that the fetus is descending further into the pelvis, leading towards delivery.