A nurse is collecting data from a newborn who weighs 5,160 g (11 lb, 6 oz) and whose mother has diabetes mellitus. For which of the following data should the nurse monitor?

Choice A rationale :

Contractions every 3 to 4 minutes. Rationale: Contractions are a significant sign of labor. When the uterus contracts regularly and with increasing intensity, it indicates that the woman is in labor. However, contractions alone may not be enough to confirm active labor, as Braxton Hicks contractions can occur earlier in pregnancy, which are often irregular and less intense.

Choice B rationale

Pain just above the navel. Rationale: Pain above the navel is not a specific indicator of labor. In late pregnancy, the baby's head may engage in the pelvis, causing pressure and discomfort in the upper abdomen. However, this symptom alone does not confirm active labor and can be attributed to various other factors as well.

Choice C rationale

Amniotic fluid in the vaginal vault. Rationale: The presence of amniotic fluid in the vaginal vault, also known as rupture of membranes or "water breaking,”. is a significant sign that labor is likely to be in progress or imminent. When the amniotic sac ruptures, it releases the fluid that surrounds the baby in the uterus. This is a clear indication of active labor.

Choice D rationale

Cervical dilation. Rationale: Cervical dilation is one of the most reliable signs of active labor. As the uterus contracts, the cervix starts to dilate and efface (thin out) to allow the baby's passage through the birth canal. Measuring cervical dilation during a pelvic examination provides valuable information about the progress of labor.

The correct answer is choice A: Respiratory rate of 16/min.

Choice A rationale:

A respiratory rate of 16/min is within the normal range for adults, which is typically between 12 to 20 breaths per minute. In the context of severe preeclampsia, maintaining a normal respiratory rate is crucial when administering magnesium sulfate IV, as one of the signs of magnesium toxicity is respiratory depression. Therefore, a respiratory rate of 16/min indicates that the client is not experiencing respiratory depression and it is safe to continue the magnesium sulfate infusion.

Choice B rationale:

A heart rate of 60/min is at the lower end of the normal range, which is 60 to 100 beats per minute for adults. However, bradycardia or a low heart rate can be a sign of magnesium sulfate toxicity, especially if accompanied by other symptoms such as hypotension or altered mental status. Without additional context, a heart rate of 60/min alone does not necessarily indicate it is unsafe to continue the infusion, but it would require further assessment.

Choice C rationale:

A urine output of 50 mL in 4 hours is significantly below the expected minimum of 30 mL/hour for adults. Adequate urine output is an important indicator of kidney function and is essential for the excretion of magnesium. In the case of magnesium sulfate infusion for severe preeclampsia, a low urine output could indicate renal insufficiency and an increased risk of magnesium toxicity. Therefore, a urine output of 50 mL in 4 hours is a contraindication for continuing the infusion without further evaluation.

Choice D rationale:

Diminished deep-tendon reflexes can be a sign of magnesium toxicity. Deep-tendon reflexes are assessed to monitor for signs of magnesium overdose during infusion, as magnesium acts as a central nervous system depressant at high levels. If deep-tendon reflexes are diminished, it may suggest that the serum magnesium levels are too high, and the infusion should be paused or discontinued to prevent further toxicity.

In summary, the only finding that clearly indicates it is safe to continue the magnesium sulfate infusion is a normal respiratory rate, as provided in choice A. The other options either require further assessment or are indicators of potential magnesium toxicity.