Final answer:
The finding that requires further assessment 12 hours after birth is the fundus being palpable two fingerbreadths above the umbilicus since it suggests that the uterus is not contracting and shrinking down as expected, which can be indicative of potential complications. The correct option is D.
Step-by-step explanation:
The question pertains to the assessment of the position of the uterine fundus following childbirth. After birth, the fundus is expected to progressively decrease in size and descend back into the pelvis.
The normal progression would be for the fundus to be at the level of the umbilicus or start to descent below the umbilicus within 12 hours postpartum. Options B, C, and D describe fundus positioning consistent with the expected involution process.
However, if the fundus is palpable two fingerbreadths above the umbilicus (Option A), this would require further assessment.
A fundus that is above its expected level of involution could be indicative of complications such as uterine atony, retained placental fragments, or bladder distention, and thus warrants further investigation by a healthcare provider. The correct option is D.