Review of a primiparous woman's labor and birth record reveals a prolonged second stage of labor and extended time in the stirrups. Based on an interpretation of these findings, the nurse would be especially alert for which of the following?

Choice A rationale A prolonged second stage of labor requires the mother to maintain the lithotomy position (hips flexed, knees flexed, and legs abducted) in stirrups for an extended period. This position, particularly when combined with potential trauma to the vasculature during birth, causes compression of the popliteal veins and decreased blood flow, significantly increasing the risk of venous stasis and subsequent formation of a deep vein thrombosis (DVT), a form of thrombophlebitis, in the lower extremities. Choice B rationale Uterine subinvolution, the failure of the uterus to return to its non-pregnant state, is typically caused by retained placental fragments or endometritis (infection). While it is a common postpartum complication, it is not primarily associated with the mechanical factors of a prolonged second stage or extended time in the stirrups, which primarily impact the lower extremity circulation. Choice C rationale Retained placental fragments are the most common cause of secondary postpartum hemorrhage and are associated with a prolonged third stage of labor (after the baby's birth), not the second stage (pushing phase). The risk factors include manual removal of the placenta, previous cesarean birth, or placenta accreta, not simply the duration of pushing or positioning in stirrups. Choice D rationale Hypertension, including preeclampsia or gestational hypertension, is a condition that usually precedes and complicates labor, and is characterized by elevated blood pressure, often with proteinuria. It is a systemic vascular disorder, and its pathophysiology is not directly linked to the mechanical stress of a prolonged second stage of labor or the positioning in stirrups.