A nurse is assisting in the care of a client at 32 weeks of gestation who has been diagnosed with gestational hypertension and intrauterine growth restriction (IUGR). Which of the following pathophysiological responses should the nurse associate with this diagnosis?

Choice A rationale

The primary purpose of administering magnesium sulfate in HELLP syndrome and preeclampsia is to reduce cerebral vasospasm and provide neuroprotection to prevent eclamptic seizures. Magnesium acts as a calcium channel blocker and a central nervous system depressant, increasing the seizure threshold. It relaxes the smooth muscles of the cerebral blood vessels, improving blood flow and reducing the risk of neurological injury. This is the gold standard for seizure prophylaxis in hypertensive disorders of pregnancy.

Choice B rationale

While magnesium sulfate has a mild vasodilatory effect, it is not used as a primary antihypertensive agent to stabilize or lower blood pressure. It is often administered concurrently with actual antihypertensives like labetalol or hydralazine. If the nurse monitors the blood pressure and sees a significant drop, it is usually a secondary effect rather than the intended pharmacological goal. The focus of magnesium therapy remains the prevention of seizures rather than the management of hypertension.

Choice C rationale

Enhancing fetal lung maturity is the role of corticosteroids like betamethasone or dexamethasone, which stimulate surfactant production in the fetal lungs. Magnesium sulfate does not have this effect. While magnesium may be used for fetal neuroprotection in very early preterm births to reduce the risk of cerebral palsy, its primary indication in a mother with HELLP syndrome is specifically to protect the mother from developing life-threatening eclamptic seizures during the peripartum period.

Choice D rationale

Magnesium sulfate does not increase urine output; in fact, it is primarily excreted by the kidneys, and adequate urine output is required to prevent magnesium toxicity. A common sign of toxicity is decreased urine output (less than 30 mL/hr), as the drug accumulates in the blood when renal function is impaired. Normal magnesium therapeutic levels are 4 to 7 mEq/L. The nurse must monitor intake and output closely to ensure the client is clearing the medication safely. .

Choice A rationale

Monitoring thyroid stimulating hormone levels every 4 to 6 weeks is the standard of care during pregnancy because metabolic demands increase significantly as the fetus develops. Normal non-pregnant TSH levels typically range from 0.5 to 5.0 mIU/L, but during the first trimester, the goal is often lower to prevent developmental delays or miscarriage. Frequent testing ensures that the levothyroxine dosage remains therapeutic to meet the physiological requirements of both the mother and the growing fetus.

Choice B rationale

Doubling the dose of levothyroxine three times a week is an imprecise and potentially dangerous method of medication adjustment. While many pregnant women do require an increase in their thyroid hormone replacement, usually by 25 to 50 percent, this must be guided by specific lab results and provider orders. Indiscriminate dosing increases can lead to iatrogenic hyperthyroidism, which carries risks such as maternal tachycardia, hypertension, and potential fetal growth restriction due to excessive metabolic stimulation.

Choice C rationale

Cranberry juice does not have a known significant pharmacological interaction with the absorption or metabolism of levothyroxine. While certain substances like soy, walnuts, or high-fiber diets can interfere with how the body absorbs synthetic thyroid hormone, cranberry juice is generally considered safe. Patients should focus on consistent timing and avoiding actual inhibitors rather than restricting unrelated fluids. Maintaining adequate hydration is important during pregnancy, and cranberry juice is often used to support urinary tract health.

Choice D rationale

Prenatal vitamins often contain calcium and iron, both of which significantly impair the absorption of levothyroxine in the gastrointestinal tract. To ensure maximum bioavailability, levothyroxine should be taken on an empty stomach, and interfering substances like minerals should be separated by at least 4 hours, not just 2 hours. Taking them too close together can result in subtherapeutic hormone levels, leading to persistent hypothyroidism which can negatively impact fetal neurological development and maternal health.