What Head Engagement in
1. Floating: At the beginning of pregnancy, the baby's head is not yet engaged. It is free to move above the mother's pelvis, often referred to as "floating".
2. Engaged: As the pregnancy progresses, the baby's head begins to descend into the pelvis. When the widest part of the head, called the biparietal diameter, reaches the level of the mother's ischial spines (bony landmarks in the pelvis), the head is considered engaged.
3. Station: The station of the head refers to its position in relation to the ischial spines. It is measured in centimeters, with 0 station indicating that the head is at the level of the ischial spines. Negative stations indicate that the head is above the ischial spines, while positive stations indicate that it has descended below them.
4. Descent: Once the head is engaged, it continues to descend into the pelvis as the pregnancy progresses. The descent of the head is facilitated by uterine contractions, which help to mold and push the head down into the pelvis.
The level of head engagement is assessed during prenatal examinations and plays an important role in determining the course of labor. If the head is not engaged by the time labor begins, it may be necessary to use forceps or vacuum extraction to assist with delivery.