engagement
The descent of the fetal presenting part (usually the head) into the pelvic inlet, typically occurring in the final weeks of pregnancy.
Full Definition
Fetal engagement occurs when the presenting part, most commonly the fetal head, descends into the pelvic inlet and the widest part passes through the pelvic brim. In nulliparous women, engagement typically occurs 2-4 weeks before labor onset, while in multiparous women it may not occur until labor begins. Engagement is assessed through abdominal palpation and vaginal examination, often described as the head being 'fixed' or no longer ballotable. This process indicates that the pelvic inlet is adequate for the fetal head size, providing reassurance about the likelihood of successful vaginal delivery. Non-engagement near term may suggest cephalopelvic disproportion or malpresentation.
Usage
Usage note: Distinguish from station, which measures depth of descent after engagement has occurred.
In Context
- "Fetal head engagement was confirmed by abdominal palpation at 37 weeks." — Prenatal examination record
- "Non-engagement at term prompted evaluation for possible cephalopelvic disproportion." — Obstetric consultation note