side by side comparison

Preterm Labor vs Preeclampsia: Same Drug, Different Reason — Why Magnesium Changes Purpose

Magnesium sulfate hangs on the IV pole for both patients — but if you can't articulate why, you'll pick the wrong nursing priority. The NCLEX asks "why is this client receiving mag?" and choosing "to stop contractions" when the answer is "to prevent seizures" costs you the question.

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Comparison

Side-by-side2 compared
Dimension
Preterm Labor
Preeclampsia
Pathophysiology & risk
  • Contractions + cervical change before 37 wk
  • Infection, multiples, prior preterm birth
  • New HTN ≥ 140/90 + proteinuria after 20 wk
  • Nulliparity, chronic HTN, multiples
Signs & symptoms
  • Regular contractions
  • cervical dilation
  • Low back pain, pelvic pressure
  • BP ≥ 140/90
  • proteinuria
  • edema
  • Headache, visual changes, RUQ pain (severe)
Diagnostics & labs
  • Cervical length
  • fetal fibronectin
  • GBS culture
  • BP ×2
  • urine protein
  • Platelets, LFTs, creatinine (HELLP)
Nursing priorities
  • Tocolytics to delay
  • betamethasone for lungs
  • ★Mag for fetal neuroprotection < 32 wk
  • ★Mag for seizure prophylaxis
  • Antihypertensives
  • seizure precautions
  • I&O
Treatment & meds
  • Mag therapeutic range 4–7 mEq/L
  • Mag = neuroprotection, NOT tocolysis
  • Tocolytics: nifedipine, indomethacin
  • Mag therapeutic range 4–7 mEq/L
  • Mag prevents seizures, does NOT lower BP
  • Labetalol, hydralazine, nifedipine for BP
Patient teaching
  • Report contractions or leaking fluid
  • Betamethasone given 24–34 wk for lungs
  • Report headache, vision changes, RUQ pain
  • Daily weights
  • home BP monitoring
Red flags — escalate
  • ★Mag toxicity: ↓ reflexes, RR < 12, UOP < 30
  • Mag toxicity then IV calcium gluconate
  • ★Eclamptic seizure
  • severe HTN then stroke
  • Mag toxicity then IV calcium gluconate
Complications
  • Prematurity: immature lungs, brain, organs
  • Eclampsia, HELLP, stroke, organ damage
Pathophysiology & risk

Preterm Labor

  • Contractions + cervical change before 37 wk
  • Infection, multiples, prior preterm birth

Preeclampsia

  • New HTN ≥ 140/90 + proteinuria after 20 wk
  • Nulliparity, chronic HTN, multiples
Signs & symptoms

Preterm Labor

  • Regular contractions
  • cervical dilation
  • Low back pain, pelvic pressure

Preeclampsia

  • BP ≥ 140/90
  • proteinuria
  • edema
  • Headache, visual changes, RUQ pain (severe)
Diagnostics & labs

Preterm Labor

  • Cervical length
  • fetal fibronectin
  • GBS culture

Preeclampsia

  • BP ×2
  • urine protein
  • Platelets, LFTs, creatinine (HELLP)
Nursing priorities

Preterm Labor

  • Tocolytics to delay
  • betamethasone for lungs
  • ★Mag for fetal neuroprotection < 32 wk

Preeclampsia

  • ★Mag for seizure prophylaxis
  • Antihypertensives
  • seizure precautions
  • I&O
Treatment & meds

Preterm Labor

  • Mag therapeutic range 4–7 mEq/L
  • Mag = neuroprotection, NOT tocolysis
  • Tocolytics: nifedipine, indomethacin

Preeclampsia

  • Mag therapeutic range 4–7 mEq/L
  • Mag prevents seizures, does NOT lower BP
  • Labetalol, hydralazine, nifedipine for BP
Patient teaching

Preterm Labor

  • Report contractions or leaking fluid
  • Betamethasone given 24–34 wk for lungs

Preeclampsia

  • Report headache, vision changes, RUQ pain
  • Daily weights
  • home BP monitoring
Red flags — escalate

Preterm Labor

  • ★Mag toxicity: ↓ reflexes, RR < 12, UOP < 30
  • Mag toxicity then IV calcium gluconate

Preeclampsia

  • ★Eclamptic seizure
  • severe HTN then stroke
  • Mag toxicity then IV calcium gluconate
Complications

Preterm Labor

  • Prematurity: immature lungs, brain, organs

Preeclampsia

  • Eclampsia, HELLP, stroke, organ damage

★ marks the fact that sets a column apart.

Clinical Pearl

Preterm mag protects the fetal brain; preeclampsia mag protects the maternal brain — same drug, opposite patient.

Component Topics

PreeclampsiaPreterm Labor

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