Your patient is receiving magnesium sulfate for neuroprotection and preterm labor at 1 gram/hour. The most concerning vital sign below is:

Choice A: Prolapsed cord is not a likely complication, as it is characterized by a sudden onset of severe variable decelerations of the fetal heart rate and a visible or palpable cord in the vaginA. The nurse should identify a prolapsed cord as a medical emergency and perform immediate interventions to relieve the cord compression and deliver the fetus.

Choice B: Premature rupture of membranes is not a likely complication, as it is characterized by a gush or a trickle of clear or yellowish fluid from the vagina and a positive nitrazine or fern test. The nurse should identify premature rupture of membranes as a risk factor for infection and monitor the fetal heart rate and the maternal temperaturE.

Choice C: Abruptio placentae is a likely complication, as it is characterized by continuous abdominal pain and dark red vaginal bleeding and a board-like abdomen. The nurse should identify abruptio placentae as a life-threatening condition that involves the premature separation of the placenta from the uterine wall and can cause fetal distress and maternal hemorrhagE.

Choice D: Placenta previa is not a likely complication, as it is characterized by painless bright red vaginal bleeding and a soft and relaxed uterus. The nurse should identify placenta previa as a condition that involves the abnormal implantation of the placenta near or over the cervical os and can cause fetal hypoxia and maternal hemorrhagE.