During a high-risk delivery with a breech presentation, which type of breech is described when the buttocks present first?

The correct identification of the type of breech presentation where the buttocks present first is crucial for understanding fetal positioning during delivery. In a complete breech presentation, the fetus is positioned such that both the buttocks and the legs are folded at the knees, resulting in the buttocks leading with the legs tucked down, resembling a seated position. This is distinct from other types of breech presentations.

In contrast, a frank breech presentation involves the buttocks leading as well, but the legs are extended and positioned upwards alongside the body, which does not match the description of the buttocks presenting first while considering the position of the legs. An incomplete breech also features the buttocks leading but with one or both legs extending downwards, leaving it less clearly categorized as a buttock-first presentation. Lastly, a transverse lie refers to the fetus lying horizontally across the uterus, which does not involve a breech positioning scenario at all.

Thus, the complete breech presentation is correctly identified as the type where the buttocks present first, making it the right choice in this context.