Choice A rationale

An ectopic pregnancy, where the fertilized egg attaches outside the uterus, often presents with unilateral, cramp-like abdominal pain. This is because as the fertilized egg grows in an area where it cannot survive, it can cause irritation and bleeding, leading to pain. This pain is often one-sided or unilateral and can vary from mild to severe. It’s one of the key symptoms that can suggest an ectopic pregnancy in the early weeks of gestation.

Choice B rationale

Severe nausea and vomiting are not typically the primary symptoms associated with an ectopic pregnancy. While nausea can be a symptom of early pregnancy, severe nausea and vomiting alone without other symptoms would not necessarily indicate an ectopic pregnancy.

Choice C rationale

Uterine enlargement greater than expected for gestational age is not a symptom of an ectopic pregnancy. In fact, because the pregnancy is not in the uterus, the size of the uterus may not correlate with the expected size at the given gestational age.

Choice D rationale

While vaginal bleeding can occur in an ectopic pregnancy, it is not typically a large amount. The bleeding is often lighter than normal menstrual bleeding and may be associated with a change in color of the vaginal discharge.

The correct answer is choice C: Respiratory rate.

Choice A rationale:

Fetal heart rate (FHR) is an important assessment for clients experiencing preterm labor, but it is not the priority assessment when administering magnesium sulfate. FHR monitoring is crucial to ensure fetal well-being but is not directly related to the potential adverse effects of magnesium sulfate.

Choice B rationale:

Temperature is an essential assessment parameter, but it is not the priority in this case. Magnesium sulfate administration can cause adverse effects, particularly on the respiratory system, which should be closely monitored.

Choice C rationale:

Respiratory rate is the correct choice because respiratory rate is a priority assessment when administering magnesium sulfate. The drug can cause respiratory depression and other respiratory complications, so monitoring the respiratory rate is essential to ensure the client's safety.

Choice D rationale:

Bowel sounds are not a priority assessment for a client receiving magnesium sulfate. While gastrointestinal side effects can occur with magnesium sulfate use, respiratory assessments take precedence.

In conclusion, the priority nursing assessment for a client receiving magnesium sulfate is the respiratory rate due to the potential respiratory complications associated with the drug. Monitoring respiratory function closely can help prevent adverse outcomes and ensure the client's safety during treatment.