A 25-year-old nulliparous woman at 40 weeks gestation presents in spontaneous labor. Following an uncomplicated first stage, she is fully dilated, effaced, and at +1 station. The patient begins active maternal expulsive efforts. During this phase, the fetus must perform specific biomechanical adaptations to successfully navigate the maternal pelvis. Arrange the following cardinal movements of labor in the correct chronological sequence for a fetus in a standard vertex presentation.
- 1Engagement
- 2Flexion
- 3Internal rotation
- 4Extension
- 5External rotation (Restitution)
Cevap
The correct chronological sequence is: Engagement, Flexion, Internal rotation, Extension, External rotation (Restitution).
The cardinal movements of labor describe the physiological adaptations of the fetus during a vaginal delivery. For a cephalic presentation, the established chronological sequence is: (1) Engagement, where the fetal head enters the pelvic inlet; (2) Descent (which is continuous throughout); (3) Flexion, triggered by pelvic floor resistance, which presents the smallest head diameter; (4) Internal rotation, aligning the head anteroposteriorly; (5) Extension, where the head is delivered beneath the pubic symphysis; and (6) External rotation (restitution), where the newly delivered head realigns with the shoulders.
Adım Adım Çözüm
Anahtar Kavram
The cardinal movements of labor are the sequential biomechanical and positional changes the fetus undergoes to adapt to the maternal pelvis during vaginal delivery.