The nurse caring for a patient in labor knows factors that affect the progression of labor and birth are: Select all that apply.

A. Voluntary bearing down efforts: The strength, timing, and coordination of the mother's pushing efforts significantly affect fetal descent and the progress of the second stage of labor. Ineffective bearing down can delay birth, while effective efforts promote smoother fetal expulsion. B. The shape of the woman's bony pelvis: Pelvic shape and dimensions determine how easily the fetal head can pass through the birth canal. A gynecoid pelvis is most favorable, whereas android or platypelloid types can impede progress and increase labor complications. C. Antibiotic administration for a GBS + patient: While antibiotics are essential for preventing neonatal infection, they do not influence the physical mechanics or progression of labor. Their purpose is prophylactic rather than to affect the labor process itself. D. Size of the fetal head: A large fetal head relative to the maternal pelvis can lead to cephalopelvic disproportion, slowing or arresting labor progress. Optimal fit between fetal head size and pelvic dimensions promotes efficient descent and delivery. E. Presentation of the fetus: The way the fetus enters the pelvis—whether cephalic, breech, or face presentation—directly affects labor progression. Cephalic presentation, especially occiput anterior, allows for smoother navigation through the pelvis.