Final answer:
Increased risk of umbilical cord prolapse is considered for a client with a fetus in a breech presentation, leading to more frequent deliveries by Caesarian section. Therefore, the correct option is a.
Step-by-step explanation:
The complication a nurse would consider for a client with a fetus in a breech presentation is A. "Increased risk of umbilical cord prolapse". In a breech presentation, the baby's buttocks or feet are positioned to come out first during birth, which can lead to an increased risk of the umbilical cord getting compressed or prolapsed as part of the body creates a space before the widest part, the head, comes through the birth canal. This can compromise the baby's oxygen supply. Because of these risks, most breech presentations today lead to delivery by Caesarian section. Other options B, C, and D are less likely or incorrect as breech presentation generally increases, rather than decreases, the risks of obstructed labor, perineal trauma, and the need for a cesarean section.