From the Research
Fetal station positions should be assessed using transabdominal sonography, as it provides a simple and accurate method for determining fetal head position and station during labor, as demonstrated in the most recent study 1. Fetal station refers to the position of the fetal presenting part (usually the head) in relation to the ischial spines of the maternal pelvis during labor. Stations are measured in centimeters, ranging from -5 to +5. The ischial spines represent station 0, which is the midpoint of the birth canal. Negative stations (-5 to -1) indicate that the presenting part is above the ischial spines and still high in the pelvis. Station 0 means the presenting part is at the level of the ischial spines. Positive stations (+1 to +5) indicate the presenting part has descended below the ischial spines and is progressing toward delivery, with +5 representing crowning at the perineum.
Some key points to consider when assessing fetal station positions include:
- The use of ultrasound-based systems, such as LaborPro, can provide accurate and reliable measurements of fetal head station and position during labor, as shown in studies 2 and 3.
- Transperineal ultrasound can also be used to assess fetal head descent and station during labor, with high intraobserver and interobserver agreement, as demonstrated in study 4.
- The assessment of fetal station is crucial during labor, as it helps healthcare providers track the progress of descent through the birth canal and identify potential complications, such as cephalopelvic disproportion or malposition.
- Abnormal or arrested descent may indicate the need for intervention, such as instrumental delivery or cesarean section, as discussed in study 3.
- The fetal reserve index, a modified approach to electronic fetal monitoring, can provide a quantitative assessment of fetal well-being and help identify babies at risk of in utero injury, as described in study 5.
Overall, the assessment of fetal station positions is a critical component of labor management, and the use of ultrasound-based systems and transabdominal sonography can provide accurate and reliable measurements to inform clinical decision-making.