Hypertensive & Metabolic Disorders of Pregnancy - Cheat Sheet
Your last-minute reference for high-yield content on preeclampsia, eclampsia, magnesium sulfate management, gestational diabetes, and hyperemesis gravidarum. Every item here has appeared on recent NLE exams.
Hypertensive Disorders Classification
Common values
Value
≥160/110 mmHg
Symbol
Severe BP
Quantity
Severe hypertension threshold
Value
≥300 mg
Symbol
Protein
Quantity
Proteinuria threshold (24-hour urine)
Value
< 100,000/μL
Symbol
Platelets
Quantity
Platelet threshold (HELLP)
Important facts
- Pathophysiology: GENERALIZED VASOSPASM from abnormal placentation → reduced perfusion to placenta, kidneys, liver, brain, eyes
- Vasospasm increases vascular permeability → fluid shifts out of intravascular space → intravascular VOLUME DEPLETION despite tissue edema and total-body fluid overload
- DO NOT use aggressive diuresis or routine fluid loading in preeclampsia — woman is fluid-overloaded tissues but volume-contracted in vessels → fluid must be given cautiously with pump and strict monitoring to avoid pulmonary edema
- Proteinuria alone does not define preeclampsia; end-organ dysfunction (CNS, liver, kidney, hematologic) OR severe BP elevation can substitute
- HELLP raises risk of DIC, hepatic rupture, placental abruption; AVOID liver palpation due to rupture risk
Key definitions
Gestational Hypertension
Example
Patient at 28 weeks with BP 142/94, negative urine protein, no symptoms.
BP ≥140/90 mmHg after 20 weeks WITHOUT proteinuria; resolves postpartum.
Preeclampsia
Example
BP 145/92 + 2+ proteinuria + platelets 95,000; meets criteria for preeclampsia.
BP ≥140/90 after 20 weeks WITH proteinuria OR signs of end-organ involvement (thrombocytopenia, liver/renal impairment, pulmonary edema, cerebral/visual symptoms).
Severe Preeclampsia
Example
BP 165/115 + blurred vision + right-sided abdominal pain = preeclampsia with severe features.
BP ≥160/110 mmHg OR features: severe persistent headache, visual disturbances, epigastric/RUQ pain, hyperreflexia with clonus, oliguria, pulmonary edema, thrombocytopenia, elevated liver enzymes.
Eclampsia
Example
Woman with preeclampsia has generalized convulsions; now she has eclampsia.
Preeclampsia PLUS tonic-clonic seizures not attributable to another cause.
Chronic Hypertension with Superimposed Preeclampsia
Example
Woman on antihypertensives before pregnancy; at 24 weeks new proteinuria develops.
Pre-existing hypertension + new proteinuria or worsening end-organ signs after 20 weeks; HIGHEST risk for maternal/fetal complications.
HELLP Syndrome
Example
Preeclamptic woman + low platelets (< 100,000) + elevated transaminases + schistocytes on blood smear.
Hemolysis + Elevated Liver enzymes + Low Platelets; severe variant of preeclampsia; often presents with right-sided pain, nausea, malaise.
Diagrams to know
- Spectrum of hypertensive disorders in pregnancy (gestational → preeclampsia → eclampsia)
- End-organ involvement in preeclampsia (CNS, cardiac, hepatic, renal, hematologic)
Magnesium Sulfate — High-Alert Drug
Formulas
Loading dose: 4–6 g IV over 15–30 minutes
Meaning
Initial dose to rapidly raise serum magnesium to therapeutic level; given as bolus push or slow IV infusion
Watch out
Do NOT dilute in less than 100 mL fluid; do NOT push faster than 15–30 minutes or severe flushing, diaphoresis, nausea occur; NOT compatible with Ca gluconate in same IV line
When to use
At diagnosis of preeclampsia with severe features or eclampsia; BEFORE or AT TIME OF DELIVERY for seizure prevention
Maintenance infusion: 1–2 g/hour continuous IV (always on infusion pump)
Meaning
Sustained plasma magnesium at therapeutic level; 1 g typical maintenance for most women
Watch out
Must use infusion pump, NOT gravity flow; never give as bolus; if woman vomits or IV infiltrates, rebolus with 4–6 g; do NOT rely on IM dosing (unpredictable absorption)
When to use
Continued for 12–24 hours after delivery (or until convulsion-risk period passes); through labor and delivery
Therapeutic serum level: 4–7 mEq/L (approximately 4.8–8.4 mg/dL)
Meaning
Range at which seizures are prevented and toxicity is not yet present; clinical monitoring replaces serum levels in most settings
Watch out
Below 4 mEq/L, seizure prevention fails; above 7–10 mEq/L, toxicity signs appear; most NLE questions test clinical signs, NOT serum levels
When to use
As target for loading/maintenance; if serum level is checked, keep in this range
Common values
Value
4–6 g over 15–30 min
Symbol
MgSO4 load
Quantity
Loading dose IV
Value
1–2 g/hour
Symbol
MgSO4 maint
Quantity
Maintenance infusion
Value
4–7 mEq/L
Symbol
Mg level
Quantity
Therapeutic serum level
Value
8–10 mEq/L
Symbol
DTRs absent
Quantity
Toxicity DTR loss onset
Value
10–12 mEq/L
Symbol
RR < 12
Quantity
Respiratory depression onset
Value
1 g (10 mL of 10%) IV over ~3 min
Symbol
Ca gluconate
Quantity
Antidote dose
Important facts
- FIRST SIGN OF TOXICITY: Loss of deep tendon reflexes (DTRs) — especially patellar reflex → DO NOT PROCEED with next dose; HOLD infusion
- Toxicity signs appear in SEQUENCE: DTRs absent (8–10 mEq/L) → respiratory depression RR < 12/min (10–12 mEq/L) → oliguria (< 30 mL/hr) → level of consciousness decreased → cardiac/respiratory arrest (very high levels)
- Assess DTRs + respiratory rate + urine output BEFORE each loading dose and every 1–2 hours during maintenance
- Oliguria (< 30 mL/hr) is CRITICAL: magnesium is 100% renally cleared; if kidney function ↓, drug accumulates → toxicity
- Calcium gluconate (magnesium antagonist) is the ANTIDOTE and must be at bedside during ANY magnesium infusion
- Magnesium does NOT lower BP; it is NOT a primary antihypertensive — use hydralazine, labetalol, nifedipine, or methyldopa for severe BP
- Magnesium is compatible with oxytocin but NOT with calcium gluconate, sodium bicarbonate, or PPV in same IV line
- Maternal side effects: flushing, diaphoresis, warmth, chest heaviness, nausea, transient hypotension; neonatal: hypotonia, respiratory depression, poor feeding (transient)
Key definitions
Magnesium Sulfate Mechanism
Example
Prevents eclamptic convulsions by raising seizure threshold, not by lowering BP (it is NOT an antihypertensive).
CNS depressant; relaxes smooth muscle; raises seizure threshold by blocking N-methyl-D-aspartate (NMDA) receptors and stabilizing neuronal membranes.
Magnesium Toxicity
Example
Woman on magnesium maintenance; patellar reflex absent, RR 10, urine output 20 mL/hr → hold infusion, get serum level, prepare antidote.
Overdose of magnesium causing progressive CNS/respiratory depression; serum level > 10 mEq/L or clinical signs (lost DTRs, RR < 12, oliguria).
Diagrams to know
- Magnesium sulfate dosing timeline (loading → maintenance → duration)
- Toxicity signs progression and management flowchart
Reactions or equations
Mg2+ + NMDA receptor antagonism + neuronal membrane stabilization → ↑ seizure threshold
Note
Magnesium PREVENTS seizures; it does NOT stop an active seizure (need benzodiazepine for that)
Conditions
Therapeutic magnesium plasma level; occurs over 30 min to 1 hour after loading dose
Calcium gluconate + Mg2+ → Mg2+ antagonized → reversal of toxicity signs
Note
Calcium is rapid-acting antagonist; give slowly to avoid cardiovascular effects; effect lasts ~30 min, so may need continued monitoring/supportive care
Conditions
IV calcium gluconate 1 g over 3 minutes at bedside if toxicity signs appear
Antihypertensive Agents in Pregnancy
Common values
Value
≥160/110 mmHg
Symbol
Acute TX threshold
Quantity
Severe BP threshold
Value
5–10 mg
Symbol
Hydralazine
Quantity
Hydralazine IV dose
Value
20 mg IV
Symbol
Labetalol
Quantity
Labetalol starting dose
Value
10–20 mg
Symbol
Nifedipine
Quantity
Nifedipine oral dose
Important facts
- Severe hypertension threshold requiring treatment: BP ≥160/110 mmHg
- Goal of acute antihypertensive therapy: reduce BP by 15–20% in first hour to prevent maternal stroke without compromising fetal perfusion
- DO NOT drop BP too rapidly or too much; sudden BP ↓ reduces placental perfusion → fetal distress
- Hydralazine: monitor for reflex tachycardia, fetal heart rate changes; most experience with use in pregnancy
- Labetalol: escalating dosing protocol; preferred first-line agent in many guidelines; contraindications: asthma, COPD, heart failure, bradycardia < 60
- Nifedipine PO: commonly used; risk of hypotension if combined with IV magnesium → space dosing or use alternative agent
- Methyldopa: safe long-term agent; used for chronic hypertension control pre- and post-pregnancy; slow onset so not ideal for acute BP crisis
- No routine diuretics in preeclampsia: they reduce intravascular volume further (which is already depleted) → placental perfusion ↓
Key definitions
First-Line Antihypertensives (Acute Severe Hypertension)
Example
BP 170/120 + severe headache → give hydralazine 5–10 mg IV or labetalol 20 mg IV.
Hydralazine, labetalol, or nifedipine; used for BP ≥160/110 mmHg to prevent maternal stroke.
Hydralazine
Example
Give 5 mg IV; if no response in 20 min, repeat; watch for sudden BP drop and fetal heart rate changes.
Vasodilator; IV dose 5–10 mg; onset 5–20 min, duration 3–8 hours; monitor for maternal hypotension and reflex tachycardia.
Labetalol
Example
BP 165/115 → labetalol 20 mg IV; if BP still > 160/110 in 10 min, give 40 mg; repeat escalation as needed.
Combined alpha- and beta-blocker; IV 20 mg initially, escalating doses (40 mg, 80 mg, 160 mg) every 10 min up to max 220 mg; onset 5–10 min; avoid in asthma, heart failure, bradycardia.
Nifedipine (Immediate-Release)
Example
BP 162/108 → nifedipine 10 mg PO; recheck BP in 20 min, repeat 10 mg if needed.
Calcium channel blocker; oral 10–20 mg; onset 15–30 min; monitor for hypotension; contraindicated with magnesium IV (hypotension risk).
Methyldopa
Example
Woman with chronic hypertension on methyldopa 500 mg BID; continue throughout pregnancy and postpartum.
Central-acting agent; oral; used for chronic/long-term BP control in pregnancy; slow onset (4–6 hours); safe in pregnancy.
Agents to AVOID in Pregnancy
Example
Patient on lisinopril before pregnancy; STOP at positive pregnancy test; switch to methyldopa or nifedipine.
ACE inhibitors and ARBs (teratogenic: fetal renal dysgenesis, oligohydramnios, IUGR, fetal renal failure, neonatal hypotension); atenolol (IUGR); diuretics (hypovolemia worsens placental perfusion).
Diagrams to know
- Antihypertensive agent selection based on clinical scenario (acute vs chronic, contraindications)
Nursing Management of Preeclampsia/Eclampsia
Common values
Value
< 30 mL/hr or < 500 mL/24 hr
Symbol
Urine output
Quantity
Oliguria threshold
Value
2+
Symbol
DTR grade
Quantity
Normal DTR
Value
3–4+
Symbol
DTR grade
Quantity
Hyperreflexia
Value
≥1 sustained beat
Symbol
Clonus
Quantity
Clonus beats (concerning)
Important facts
- Position: LEFT LATERAL RECUMBENT position continuously (maximizes placental perfusion, prevents aortocaval compression)
- Environment: QUIET, DIM ROOM; limit visitors; minimize stimulation (loud noise, bright light, palpation) — sensory stimulation can PRECIPITATE seizure
- Foley catheter: essential for accurate urine output monitoring; oliguria (< 30 mL/hr or < 500 mL/24 hr) indicates kidney hypoperfusion and magnesium accumulation risk
- Vital signs and monitoring: BP every 4 hours (or continuously if on treatment); DTRs and clonus every 4 hours (or more frequently during/after magnesium); RR, FHR, daily weight
- Strict intake/output: every hour during acute phase; IV fluids given cautiously with pump (woman is intravascularly depleted); avoid routine fluid boluses
- Labs: CBC (platelets, hematocrit for hemolysis), liver enzymes, uric acid, creatinine, coagulation studies at diagnosis and before/after severe features
- Seizure precautions ALWAYS in place: padded rails, suction/O2 at bedside, crash cart accessible, IV access patent, calcium gluconate at bedside
- During seizure: turn to side immediately, do NOT restrain, protect head/extremities from injury, do NOT force anything into mouth, let seizure run course (typically 60–90 sec)
- After seizure: suction secretions, give O2, assess fetal status, assess maternal vital signs and level of consciousness, notify provider, prepare for delivery
- Delivery IS THE CURE: ultimate management of preeclampsia/eclampsia is delivery of baby and placenta; timing depends on severity and gestational age
Key definitions
Seizure Precautions
Example
Preeclamptic woman in hospital: side rails padded and raised, suction/O2 set up, call bell within reach, room kept quiet.
Environmental safety measures to minimize stimuli and prevent injury during eclamptic seizure: padded side rails UP, suction and O2 at bedside, emergency airway available, dim quiet room, limit visitors.
Left Lateral Recumbent Position
Example
During labor and rest periods, position woman left lateral; do NOT place supine (aortocaval compression ↓ placental flow).
Woman lying on her left side; maximizes placental perfusion by relieving aortocaval compression and optimizing uterine blood flow.
Deep Tendon Reflex (DTR) Assessment
Example
Preeclamptic woman: patellar DTR 4+ with sustained clonus (foot remains in dorsiflexion, then plantarflexes 3+ times); sign of CNS irritability → seizure risk ↑.
Neurologic exam to detect hyperreflexia (preeclampsia) or absent reflexes (magnesium toxicity); grade 0–4+; normal is 2+.
Clonus
Example
Dorsiflexed ankle remains involuntarily in plantarflexion-dorsiflexion cycle; woman has hyperreflexia with clonus → preeclampsia with severe features → seizure risk.
Involuntary rhythmic muscle contractions in response to sustained stretch (e.g., sustained ankle dorsiflexion → plantarflexion 3–5 times); indicates CNS hyperexcitability; 1–2 beats sustained is CONCERNING.
Eclamptic Seizure Priority Care
Example
Woman seizes → turn to left side, hold gently (don't restrain), allow seizure to end naturally, suction airway after seizure, check FHR, prepare for CS.
During seizure: PRIMARY goal is patent airway and safety — turn to side (prevent aspiration), do NOT restrain, do NOT force anything into mouth, protect from injury; after seizure: suction secretions, O2, assess fetus, prepare for delivery.
Diagrams to know
- Preeclampsia assessment flowchart (vital signs → DTRs → clonus → seizure risk)
- Eclamptic seizure management steps
Gestational Diabetes Mellitus (GDM)
Formulas
Fasting glucose target: < 95 mg/dL
Meaning
Blood glucose measured after 8+ hours fasting; target in GDM is tighter than non-pregnant diabetes to protect fetus
Watch out
Do NOT use non-pregnant targets (< 100 mg/dL); pregnancy requires stricter control; fasting > 95 indicates inadequate overnight insulin or evening carb loading
When to use
Self-monitoring fasting glucose; HbA1c interpretation in pregnancy
1-hour postprandial glucose target: < 140 mg/dL
Meaning
Blood glucose 1 hour after start of meal; measures acute postprandial spike
Watch out
Patient may test 1 hour AFTER eating (not from start of meal); emphasize testing FROM FIRST BITE; some labs use 2-hour postprandial (< 120 mg/dL) instead
When to use
After breakfast, lunch, dinner; most common postmeal testing point in GDM
2-hour postprandial glucose target: < 120 mg/dL
Meaning
Blood glucose 2 hours after start of meal; some protocols use this instead of 1-hour
Watch out
Different labs/guidelines may use different postprandial intervals; always clarify target with facility diabetes educator
When to use
Some institutions prefer 2-hour testing; know your facility's protocol
50-g glucose challenge test (screening): threshold ≥140 mg/dL → proceed to 3-hour 100-g OGTT
Meaning
Non-fasting screening test at 24–28 weeks; no prep required; if abnormal, diagnostic OGTT required
Watch out
A value of exactly 140 is ABNORMAL (not normal); some labs use 135 or 145 depending on ethnicity-specific cutoffs; know your facility's threshold
When to use
Universal screening in most U.S./Philippine settings at 24–28 weeks
3-hour 100-g OGTT diagnostic thresholds: fasting ≤95, 1-hr ≤180, 2-hr ≤155, 3-hr ≤140 mg/dL (TWO abnormal values = GDM)
Meaning
Gold standard diagnostic test; woman fasts, then consumes 100 g glucose; blood drawn at 4 timepoints; if ≥2 values abnormal, GDM diagnosed
Watch out
Pregnant woman may have nausea with 100 g glucose drink; some vomit (test invalid, must repeat); need ALL 4 draws; missing even one draw makes result uninterpretable
When to use
After abnormal 50-g screening test
Common values
Value
< 95 mg/dL
Symbol
Fasting
Quantity
Fasting glucose target (GDM)
Value
< 140 mg/dL
Symbol
1-hr post
Quantity
1-hour postprandial target
Value
< 120 mg/dL
Symbol
2-hr post
Quantity
2-hour postprandial target
Value
≥140 mg/dL
Symbol
Screen abnormal
Quantity
50-g screening threshold
Value
4,000 g
Symbol
Birth weight
Quantity
Macrosomia threshold
Value
< 40–50 mg/dL
Symbol
Infant glucose
Quantity
Neonatal hypoglycemia
Important facts
- Prevalence: 3–10% of pregnancies; risk factors: obesity, age > 25, family history of type 2 DM, previous macrosomic infant, previous GDM
- Pathophysiology: placental hormones (especially human placental lactogen at 3rd trimester) increase insulin resistance → maternal beta cells unable to compensate → hyperglycemia
- Maternal complications: preeclampsia, polyhydramnios, recurrent UTIs/candidal infections, increased C-section rate, higher risk of type 2 DM postpartum (35–60% within 5–10 years)
- Fetal/neonatal complications: MACROSOMIA (> 4,000 g), shoulder dystocia, birth trauma, neonatal hypoglycemia, respiratory distress syndrome, hyperbilirubinemia; congenital anomalies if pre-existing diabetes (NOT GDM)
- Screening: universal 50-g glucose challenge test at 24–28 weeks; NO fasting required; if ≥140 mg/dL (or 135 per some protocols), proceed to 3-hour 100-g OGTT
- Diagnosis: 3-hour 100-g OGTT with ≥2 abnormal values (fasting ≤95, 1-hr ≤180, 2-hr ≤155, 3-hr ≤140 mg/dL)
- First-line management: DIET (controlled carbohydrate, consistent timing, small frequent meals) and EXERCISE (30 min moderate activity most days)
- Insulin added when diet + exercise fail to meet glycemic targets; insulin is SAFEST, does NOT cross placenta, can be adjusted freely; preferred over oral agents
- Self-monitoring blood glucose: fasting and 1-hour postmeal ×3 (after each main meal) = 4 readings/day minimum
- Monitoring: weekly or biweekly glucose logs reviewed by diabetes educator; HbA1c can be checked but target < 6.5% (though pregnancy targets are tight); fetal U/S for growth and AFV
- Delivery timing: most deliver at 39 weeks (or earlier if complications); avoid macrosomia by tight glucose control
- Postpartum: GDM resolves in ~90% after delivery BUT lifelong type 2 DM risk is 35–60%; requires 6–12 week postpartum glucose tolerance test and annual screening thereafter
Key definitions
Gestational Diabetes Mellitus (GDM)
Example
Woman screened at 26 weeks, 50-g test 155 mg/dL, 3-hour OGTT shows 2 abnormal values → GDM diagnosed.
Glucose intolerance first recognized in pregnancy (not pre-existing diabetes); caused by placental hormones (hPL, progesterone, cortisol) creating insulin resistance; pancreas cannot compensate → hyperglycemia.
Insulin in Pregnancy
Example
GDM patient on diet alone; fasting glucose 110 mg/dL despite diet compliance → start insulin (human insulins like NPH, regular, or analogs like aspart, glargine).
SAFEST glucose-lowering agent in pregnancy (does NOT cross placenta); first-line pharmacologic agent for GDM; given SC; requires proper storage (refrigerate, protect from freezing) and injection technique teaching.
Metformin in Pregnancy
Example
GDM patient refuses insulin; metformin 1000 mg BID started; monitor glucose response.
Oral biguanide; crosses placenta minimally; used in some GDM patients when diet fails and insulin not available/acceptable; less evidence than insulin but increasingly used.
Glyburide in Pregnancy
Example
GDM patient on glyburide 5 mg daily; teach signs of hypoglycemia (shakiness, sweating, confusion).
Oral sulfonylurea; some data suggest safety in pregnancy; used in select GDM cases; less reliable than insulin; requires patient education on hypoglycemia risk.
Macrosomia
Example
Mother with GDM; fetus estimated at 4,100 g at term → increased risk of shoulder dystocia if vaginal delivery attempted.
Fetal birth weight > 4,000 g (or > 4,500 g); caused by fetal hyperinsulinemia from maternal hyperglycemia; increases shoulder dystocia, birth trauma, cesarean delivery.
Neonatal Hypoglycemia
Example
GDM mother; infant born, cord glucose 30 mg/dL; baby sweating, jittery → requires dextrose IV, frequent feeding, close monitoring.
Low blood glucose in newborn (usually < 40–50 mg/dL depending on lab); caused by continued fetal hyperinsulinemia after maternal glucose supply is cut at birth; GDM infants at high risk.
Diagrams to know
- GDM screening and diagnostic pathway (50-g test → 3-hour OGTT)
- Insulin types and timing in pregnancy
Hyperemesis Gravidarum
Common values
Value
5% pre-pregnancy weight
Symbol
HG severity
Quantity
Weight loss (diagnostic)
Value
25–50 mg daily
Symbol
Pyridoxine
Quantity
Pyridoxine (B6) dose
Value
10–25 mg TID
Symbol
Doxylamine
Quantity
Doxylamine dose
Value
100 mg IV/IM daily
Symbol
Thiamine
Quantity
Thiamine supplementation
Value
3.5–5.0 mEq/L
Symbol
K+ normal
Quantity
Normal serum potassium
Important facts
- Timing: typically starts 4–8 weeks (with rising hCG) and peaks at 11–13 weeks; usually resolves by 16–20 weeks but can persist into 2nd/3rd trimester in severe cases
- Linked to high hCG: more common in molar pregnancy, multiple pregnancy, and women with PCOS (high hCG-producing conditions)
- Assessment: severe dehydration signs (dry mucous membranes, poor skin turgor, tachycardia, hypotension, concentrated urine), weight loss > 5%, electrolyte abnormalities, ketonuria
- Electrolyte disturbances: HYPOKALEMIA (most common), METABOLIC ALKALOSIS (from HCl loss), hyponatremia, hypochloremia; magnesium depletion (not measured routinely but significant)
- Complications: DIC (in extreme cases), hepatic dysfunction, rhabdomyolysis (from hypokalemia + dehydration), Wernicke encephalopathy (thiamine deficiency), fetal growth restriction if prolonged/severe
- Management: NPO initially; IV fluid rehydration (isotonic solutions: 0.9% NS or Ringer's lactate) with electrolyte replacement, especially potassium (cautiously, 20 mEq/L IV, not > 40 mEq/L per bag)
- ALWAYS give THIAMINE supplementation: 100 mg IV/IM daily during acute phase to prevent Wernicke encephalopathy (risk with prolonged vomiting and NPO state)
- Diet advancement: start with small, frequent, dry, bland carbohydrate meals (crackers, toast, applesauce); separate fluids from solids (small sips 30–60 min after meals); avoid triggers (hot foods, strong smells, fatty foods)
- Antiemetics: FIRST-LINE = pyridoxine (B6) 25–50 mg daily ± doxylamine 10–25 mg TID; second-line = metoclopramide 10 mg TID, promethazine 12.5–25 mg Q4-6h, ondansetron 4–8 mg Q6-8h (use cautiously for cost/availability)
- Monitoring: daily weight, strict I/O (foley if severe), electrolytes (K, Na, Cl, HCO3, glucose, uric acid for hyperemesis-related pancreatitis risk), urinalysis, vital signs, fetal viability (U/S to rule out molar pregnancy)
- Psychological support: hyperemesis is exhausting; validate patient's experience, provide reassurance that it WILL resolve, involve family in meal planning/support
- Prognosis: good with appropriate treatment; fetal outcome normal if nutrition restored; maternal weight loss and electrolyte derangements reverse postpartum
Key definitions
Hyperemesis Gravidarum
Example
Woman at 10 weeks: vomits 15–20 times daily, unable to keep down any food/fluids, lost 8 kg; urine shows ketonuria, electrolytes abnormal → hyperemesis gravidarum.
Severe, persistent nausea and vomiting beyond ordinary morning sickness; causes dehydration, weight loss (> 5% pre-pregnancy weight), electrolyte imbalance, ketonuria; linked to high hCG (molar, multiple pregnancy).
Wernicke Encephalopathy (Hyperemesis Context)
Example
Woman with severe hyperemesis for weeks, not given thiamine; develops confusion and eye movement abnormalities → Wernicke encephalopathy (may be irreversible).
Thiamine (B1) deficiency caused by prolonged vomiting/starvation; presents with confusion, ataxia, ophthalmoplegia; PREVENTABLE with thiamine supplementation; serious risk in hyperemesis gravidarum.
Hypokalemia in Hyperemesis
Example
Hyperemesis patient: K+ 2.8 mEq/L (normal 3.5–5.0); has muscle weakness, palpitations → requires IV potassium replacement cautiously.
Low serum potassium from loss of gastric fluid (gastric juices rich in potassium); can cause muscle weakness, cardiac arrhythmias, rhabdomyolysis.
Metabolic Alkalosis in Hyperemesis
Example
Hyperemesis patient: pH 7.52, HCO3- 38, RCO2 48; loss of HCl in gastric fluid causes alkalosis; often accompanied by K+ 2.5.
High pH from loss of gastric acid (H+ ions) in vomitus; causes compensatory hypoventilation (low RCO2) and hypokalemia (kidneys conserve H+ to lower pH).
Pyridoxine (Vitamin B6) for Hyperemesis
Example
Hyperemesis patient started on pyridoxine 25 mg TID ± doxylamine 10–25 mg TID; nausea improves within 2–3 days.
FIRST-LINE antiemetic for hyperemesis gravidarum; safe in pregnancy; dose 25–50 mg daily; mechanism unknown but effective; often combined with doxylamine (antihistamine).
Doxylamine with Pyridoxine
Example
Woman on Diclegis (doxylamine 10 mg + pyridoxine 10 mg) BID-TID; vomiting decreases; can continue throughout pregnancy if needed.
Combination first-line therapy for hyperemesis; doxylamine is antihistamine; available as combination product (Diclegis) in some countries; both safe in pregnancy.
Diagrams to know
- Hyperemesis gravidarum assessment and management flowchart
- Electrolyte derangements and correction priorities
Reactions or equations
Loss of HCl (gastric acid) → H+ depletion → alkalosis (high HCO3-, high pH)
Note
Compensatory hypoventilation (low RCO2) tries to lower pH but is limited; hypokalemia perpetuates alkalosis
Conditions
Prolonged vomiting of gastric contents
Dehydration + hypokalemia + metabolic stress → muscle weakness, cardiac arrhythmias, potential rhabdomyolysis
Note
K+ replacement must be done cautiously; target is 3.5+ mEq/L; aim for gradual repletion (IV K+ max 40 mEq/L per bag, 10–20 mEq/hr infusion rate)
Conditions
Severe, prolonged hyperemesis without adequate replacement
Must remember
- PREECLAMPSIA = BP ≥140/90 after 20 weeks + PROTEINURIA (or end-organ signs substitute); ECLAMPSIA = preeclampsia + seizures; severity starts at BP ≥160/110 or severe features (headache, visual changes, epigastric/RUQ pain, hyperreflexia with clonus, oliguria, pulmonary edema).
- MAGNESIUM SULFATE — Loading: 4–6 g IV over 15–30 min; Maintenance: 1–2 g/hr continuous IV (pump only); Therapeutic level: 4–7 mEq/L. FIRST sign of toxicity = LOSS OF DTRs (patellar reflex absent) → HOLD infusion immediately. Then: RR < 12/min (respiratory depression), oliguria < 30 mL/hr. ANTIDOTE = Calcium gluconate 1 g (10 mL of 10%) IV over ~3 min (keep at bedside).
- MAGNESIUM MONITORING — Assess DTRs + respiratory rate + urine output BEFORE each loading dose and every 1–2 hours during maintenance. Oliguria is CRITICAL (Mg 100% renally cleared; kidney disease = accumulation = toxicity). Calcium gluconate at bedside ALWAYS when Mg infusing.
- SEVERE HYPERTENSION (BP ≥160/110) TREATMENT — First-line agents: Hydralazine 5–10 mg IV (onset 5–20 min, watch reflex tachycardia), Labetalol 20–160 mg IV escalating (onset 5–10 min, no reflex tachycardia), Nifedipine 10–20 mg PO (onset 15–30 min, avoid with IV Mg), Methyldopa (for chronic, too slow for acute). AVOID ACE/ARB (teratogenic: fetal renal damage). Goal: drop BP 15–20% first hour, NOT more (sudden drop ↓ placental perfusion).
- ECLAMPTIC SEIZURE PRIORITY = AIRWAY & SAFETY: Turn to LEFT side immediately (prevent aspiration), do NOT restrain, do NOT force anything into mouth, protect from injury, let seizure run (60–90 sec), suction airway after, give O2, check FHR, notify provider, prepare for DELIVERY (only cure). Have suction/O2 at bedside ALWAYS; seizure precautions (padded rails, crash cart) continuously.
- GESTATIONAL DIABETES SCREENING & DIAGNOSIS — 50-g glucose challenge at 24–28 weeks (no fasting); abnormal ≥140 mg/dL → proceed to 3-hour 100-g OGTT (fasting required). GDM = ≥2 abnormal values on OGTT: fasting >95, 1-hr >180, 2-hr >155, 3-hr >140 mg/dL. Daily targets: fasting <95, 1-hr postmeal <140, 2-hr postmeal <120 mg/dL. INSULIN is SAFEST (does NOT cross placenta); first-line if diet fails.
- GDM MATERNAL & FETAL COMPLICATIONS — Maternal: preeclampsia, polyhydramnios, infection (UTI, candida), ↑ C-section. Fetal: MACROSOMIA (>4,000 g → shoulder dystocia risk), NEONATAL HYPOGLYCEMIA (hyperinsulinemia continues after birth → feed early, monitor glucose), RDS (insulin delays surfactant), hyperbilirubinemia. GDM resolves postpartum in ~90%, BUT lifelong type 2 DM risk 35–60%; postpartum OGTT at 6–12 weeks and annual screening needed.
- HYPEREMESIS GRAVIDARUM = Severe, persistent N/V beyond morning sickness; causes dehydration, weight loss (>5% pre-pregnancy), ketonuria, HYPOKALEMIA + METABOLIC ALKALOSIS (from gastric HCl loss). Management: NPO initially, advance slowly; IV fluids (isotonic) + electrolyte replacement (especially K cautiously); ALWAYS give THIAMINE 100 mg IV/IM daily (prevent Wernicke encephalopathy). First-line antiemetic: PYRIDOXINE (B6) 25–50 mg daily ± DOXYLAMINE 10–25 mg TID. Diet: small frequent dry bland meals, separate fluids from solids.
- HELLP SYNDROME = Hemolysis + Elevated Liver enzymes + Low Platelets; severe preeclampsia variant; RUQ pain (hepatic involvement), nausea, malaise, risk of DIC/hepatic rupture. AVOID palpating liver (rupture risk). Management: magnesium + antihypertensives + DELIVERY.
- LEFT LATERAL RECUMBENT POSITION in preeclampsia — maximizes placental perfusion (relieves aortocaval compression); maintain continuously. QUIET, DIM ROOM (minimize stimulation → prevents seizure). SEIZURE PRECAUTIONS always: padded rails up, suction/O2 at bedside, Foley for accurate output. Monitor: BP, DTRs/clonus, RR, FHR, strict I/O (oliguria <30 mL/hr = Mg toxicity risk + kidney involvement), daily weight.
Last minute tips
- Magnesium sulfate questions on NLE almost always ask about TOXICITY SIGNS — memorize DTRs loss (earliest), respiratory depression (RR <12), oliguria (<30 mL/hr). When you see 'DTRs absent + Mg infusion,' the answer is 'HOLD infusion.' When you see 'RR 10 + oliguria + Mg,' the answer is 'Calcium gluconate' and supportive care.
- Preeclampsia = BP ≥140/90 + PROTEINURIA (this is the classic definition on NLE); end-organ signs without proteinuria can substitute, but proteinuria + elevated BP is the gold-standard diagnosis. Questions asking 'which finding CONFIRMS preeclampsia' usually point to proteinuria + elevated BP or end-organ dysfunction.
- GDM diagnosis always requires OGTT abnormality — the 50-g screening is just a screening tool (threshold ≥140). Know the 3-hour 100-g OGTT cutoffs cold: fasting ≤95, 1-hr ≤180, 2-hr ≤155, 3-hr ≤140. If an NLE question gives you a 50-g value of 155 mg/dL, the answer is 'proceed to 3-hour OGTT,' NOT 'diagnose GDM.'
- Antihypertensive agents in pregnancy — ACE/ARB are OUT (teratogenic). Know that hydralazine & labetalol are first-line for acute severe BP; labetalol now preferred by many (no reflex tachycardia). Nifedipine is common but avoid with IV Mg. Methyldopa is safe but slow (chronic use only). NLE questions test which agent to use given clinical scenario (asthma → labetalol not safe; heart failure → labetalol not safe).
- Hyperemesis gravidarum + THIAMINE is a high-yield pair on NLE — any question about prolonged N/V in pregnancy should prompt you to think 'thiamine to prevent Wernicke.' Also remember pyridoxine (B6) is first-line antiemetic (safe, effective, Category A). If you see 'hyperemesis + altered mental status,' think Wernicke (thiamine deficiency).
Comparison tables
Hypertensive Disorders of Pregnancy — Quick Comparison
| Condition | BP Criteria | Proteinuria | End-Organ Signs | Seizure | Postpartum Resolution |
|---|---|---|---|---|---|
| Gestational Hypertension | ≥140/90 after 20 wks | Absent | None | No | Yes (by 3 months) |
| Preeclampsia | ≥140/90 after 20 wks | Present (or end-organ signs substitute) | May have (thrombocytopenia, liver, renal, pulmonary edema, visual/CNS) | No | Yes (with treatment) |
| Severe Preeclampsia | ≥160/110 OR severe features | May present | Yes (headache, visual, epigastric pain, hyperreflexia/clonus, oliguria, pulmonary edema) | No (yet) | Yes (with treatment) |
| Eclampsia | Variable | Variable | Variable | YES (tonic-clonic) | Yes (after delivery) |
| Chronic Hypertension + Superimposed Preeclampsia | Pre-existing + new worsening | New proteinuria or end-organ signs after 20 wks | Yes (new or worsening) | No (unless eclampsia develops) | No (chronic hypertension persists) |
| HELLP Syndrome | ≥160/110 OR severe | May be present | Hemolysis + ↑ liver enzymes + ↓ platelets (< 100K) | RUQ pain, nausea, malaise, risk of DIC/hepatic rupture | No seizure unless eclampsia coexists |
Glucose Targets & Diagnostic Thresholds (GDM)
| Test | Timing | Normal/Target | Abnormal (Requires OGTT) |
|---|---|---|---|
| 50-g Glucose Challenge | 24–28 weeks | < 140 mg/dL (1-hour, non-fasting) | ≥140 mg/dL |
| 3-hour 100-g OGTT (Fasting) | After abnormal 50-g | ≤95 mg/dL | > 95 mg/dL (1 abnormal value) |
| 3-hour 100-g OGTT (1-hour) | After abnormal 50-g | ≤180 mg/dL | > 180 mg/dL (1 abnormal value) |
| 3-hour 100-g OGTT (2-hour) | After abnormal 50-g | ≤155 mg/dL | > 155 mg/dL (1 abnormal value) |
| 3-hour 100-g OGTT (3-hour) | After abnormal 50-g | ≤140 mg/dL | > 140 mg/dL (1 abnormal value) |
| Daily self-monitoring (Fasting) | Every morning (after 8+ hr fast) | < 95 mg/dL | ≥95 mg/dL (indicates poor overnight control/need for basal insulin) |
| Daily self-monitoring (1-hr postmeal) | 1 hour after start of each main meal (×3) | < 140 mg/dL | ≥140 mg/dL (indicates need for prandial insulin or carb reduction) |
Magnesium Sulfate — Toxicity Signs by Serum Level
| Serum Mg Level (mEq/L) | Clinical Sign | Action | Priority |
|---|---|---|---|
| 4–7 (Therapeutic) | None; seizures prevented | Continue maintenance infusion | Monitor |
| 8–10 (Early Toxicity) | Loss of deep tendon reflexes (especially patellar), warmth, flushing | HOLD infusion; do NOT give next dose; check serum Mg | CRITICAL — earliest warning sign |
| 10–12 (Moderate Toxicity) | Respiratory depression (RR < 12/min), loss of reflexes, drowsiness | HOLD infusion; monitor RR; prepare for mechanical ventilation if RR continues to drop | CRITICAL — respiratory compromise |
| 12+ (Severe Toxicity) | Oliguria (< 30 mL/hr), severe drowsiness/unconsciousness, hypotension, cardiac arrhythmias, cardiac/respiratory arrest | Give calcium gluconate 1 g IV over ~3 min; supportive care; mechanical ventilation if needed | LIFE-THREATENING |
Antihypertensive Agents — Comparison for Acute Severe BP
| Agent | Dose/Route | Onset | Duration | Key Advantages | Key Cautions |
|---|---|---|---|---|---|
| Hydralazine | 5–10 mg IV; repeat every 20 min if needed (max ~40 mg/hr infusion) | 5–20 min | 3–8 hours | Reliable in pregnancy; minimal fetal effects if BP not dropped too fast | Reflex tachycardia (avoid in cardiac disease); risk of maternal hypotension; must monitor FHR for changes |
| Labetalol | 20 mg IV; escalate 40, 80, 160 mg every 10 min (max 220 mg cumulative) | 5–10 min | 3–6 hours | Combined α/β-blockade; gradual titration; no reflex tachycardia | Avoid in asthma, COPD, bradycardia, heart failure; longer escalation time |
| Nifedipine (immediate-release) | 10–20 mg PO; repeat in 20–30 min if needed | 15–30 min | 3–6 hours | Oral route; convenient; no IV access needed | Risk of hypotension if combined with IV Mg; hypotension can precipitate fetal distress; some sources avoid >1 dose |
| Methyldopa | 250–500 mg PO TID–QID (chronic control only, NOT acute) | 4–6 hours | 12–24 hours | Very safe in pregnancy; long track record | Too slow for acute severe hypertension; used for pre-pregnancy/chronic control |
Antiemetics in Hyperemesis Gravidarum
| Agent | Class | Dose | Efficacy | Side Effects | Pregnancy Safety |
|---|---|---|---|---|---|
| Pyridoxine (B6) | Vitamin | 25–50 mg daily | FIRST-LINE; effective in 2–3 days | Minimal (peripheral neuropathy at very high chronic doses not relevant here) | Category A (safest) |
| Doxylamine | Antihistamine (H1 antagonist) | 10–25 mg TID | Enhances pyridoxine effect; common in combination formulas | Drowsiness (mild), anticholinergic effects | Category A (with pyridoxine in Diclegis) |
| Metoclopramide | Prokinetic (dopamine antagonist) | 10 mg TID–QID | Second-line; works in 1–2 days | Restlessness, tardive dyskinesia (rare with short-term use) | Category B (generally safe) |
| Promethazine | Antihistamine (H1, anticholinergic) | 12.5–25 mg Q4-6h IV/IM/PO | Second-line; rapid onset if IV | Drowsiness, hypotension, anticholinergic effects | Category C (use only if benefit outweighs risk) |
| Ondansetron | 5-HT3 antagonist (antiemetic) | 4–8 mg Q6-8h IV/PO | Second/third-line; very effective but expensive | Headache, constipation | Category B (safe but reserve for refractory cases) |
Diagrams
Magnesium Sulfate Management & Toxicity Recognition
Step-by-step flowchart for magnesium sulfate dosing, monitoring, and toxicity recognition. Shows the critical decision points (DTRs, RR, urine output) and actions to take at each stage. Essential for NLE exam preparation.
Hypertensive Disorders of Pregnancy — Classification & Features
Mind map showing the classification spectrum of hypertensive disorders in pregnancy, from gestational hypertension through eclampsia. Useful for understanding how these conditions progress and differentiate based on BP, proteinuria, and symptoms.
GDM Screening & Diagnostic Pathway
Complete diagnostic pathway for GDM from universal screening through diagnosis and management initiation. Shows decision points and exact threshold values needed for the NLE.
Eclamptic Seizure — Priority Nursing Actions
Priority actions during and after an eclamptic seizure. Emphasizes that the primary goal is airway safety, and that delivery is the definitive treatment for eclampsia.
Hyperemesis Gravidarum Course & Management
Timeline showing the typical course of hyperemesis gravidarum from onset through resolution, along with key management points at each stage.
GDM Distribution: Maternal & Fetal Complications
Pie chart showing the relative frequency of different maternal and fetal complications in GDM to illustrate that macrosomia and neonatal hypoglycemia are the most significant risks.