Final answer:
When the fetal head is fully extended and the occiput is close to the mother's spine, the presenting part during birth is typically the face. This position means that face, not occiput, leads into the birth canal, potentially complicating the delivery.
Step-by-step explanation:
When the fetal head is fully extended, and the occiput is near the spine, the presenting fetal part is typically the face. The occiput position has significant implications for the mode of delivery, often indicating a more complex birth that could require additional interventions. When the fetal head is well-extended, the chin, rather than the occiput, leads the way into the birth canal. In a normal vertex delivery, the occiput anterior position, where the fetus faces the maternal spinal cord, facilitates a smoother passage through the birth canal due to the alignment that allows the smallest part of the head (the posterior aspect called the occiput) to exit first. However, with the head extended and the occiput near the spine, this indicates a face presentation. Deliveries in face presentation are less common and may involve specific challenges. Preparing for such situations is crucial for the delivery team to ensure the safety and well-being of both the mother and the baby.