OB NURSING QUICK-REFERENCE STUDY GUIDE • Variability = BEST indicator of oxygenation (moderate = reassuring);
⚖️ TRUE VS FALSE LABOR absent/minimal/marked = concerning; >25bpm ("saltatory") =
possible acute hypoxia/cord compression
• Accelerations: ≥15bpm x15sec (15x15) or ≥10bpm x10sec if <32wk
True Labor False Labor • Monitoring freq: Stage 1 active q30min (low)/q15min (high) · Stage 2
Regular, ↑ Irregular, no progression, q15min (low)/q5min (high)
freq/duration/intensity, front/groin only, decreases • Continuous EFM if: oxytocin, epidural, PROM >24h, HTN, delayed
felt all over, worsens w/ w/ activity; no cervical stage 1/2, meconium/possible asphyxia
walking; progressive change • Bradycardia <110x10min → reposition/resuscitate, emergent birth if
cervical change unresolved
🌷 PREMONITORY SIGNS
• Lightening: descent into pelvis ~38–40wk, easier breathing, ↑
• Tachycardia >160x10min → find/treat cause (fever, distress, cardiac,
prematurity)
• Resuscitation steps: reposition, IV bolus, O2, D/C uterotonics → if no
pressure/urinary frequency, leg cramps, edema improvement, prep for birth
• Nesting: energy surge 24–48h before labor • Fetal scalp stimulation = check for FHR acceleration
• Bloody show: mucus plug + pink-tinged discharge • FSE (fetal scalp electrode) = precise internal FHR monitoring; needs
• Braxton Hicks: irregular, decrease w/ activity ROM + dilation
🎀 4 STAGES OF LABOR
• SROM: labor usually starts within 24h; risk = infection/cord prolapse • FHR categories: Cat I = routine (reassuring); Cat II = ↑ surveillance +
corrective measures; Cat III = immediate action → emergent birth if
uncorrected
Stage Key Point • Corrective ladder: reposition (lateral/knee-chest) → IV bolus → O2
1 Latent 0–6cm, mild, q5–10min → D/C oxytocin/uterotonics → amnioinfusion (variable decels, r/o
prolapse first) → fetal scalp stimulation to check for acceleration
1 Active 6–10cm, mod-strong, q2–5min, dilates • Switch to emergent delivery when: Cat III unresolved by corrective
1.2–1.5cm/hr measures, recurrent worsening decels, or prolonged
2 Expulsive Complete dilation → birth, strong q2–
📉 DECELERATIONS
decel/bradycardia doesn't recover
3min
3 Placental Birth → placenta (5–30min)
4 Restorative Placenta → 1–4h; VS q15min Type Cause / Significance
🅿️ 5 P's (+ Additional)
• Passageway, Passenger, Powers, Position, Psychological response
Early Head compression — BENIGN, gradual,
mirrors ctx
Late UPI — gradual, AFTER peak — always
🧭 STATION & POSITION
• + Philosophy, Partners, Patience, Patient prep, Pain management Cat II/III, act now
Variable Cord compression — abrupt V/U/W,
• 0 station = at ischial spines; − above, + below ≥15bpm≥15sec
• Floating = −4 to −1 · Engaged = 0 to +3 · Outlet = +4 Prolonged <60bpm, >2min<10min — OBSTETRIC
• 3-letter code: side + part (O/S/M/A) + A/P/T (e.g., LOA, ROT, LOP) EMERGENCY
🔄 CARDINAL MOVEMENTS
• Engagement = biparietal diameter through pelvic inlet Sinusoidal Smooth wave >20min = severe
distress/anemia
• Engagement → Descent → Flexion → Internal rotation → Extension 🚨 LATE DECEL — ACTION ORDER
👶 SCALP FINDINGS
→ External rotation → Expulsion • 1) Turn to LEFT side 2) O2 3) ↑ IV fluids 4) D/C oxytocin 5) Notify
provider
• Caput succedaneum: crosses sutures, resolves 3–4 days • (If on Pitocin + tachysystole → D/C oxytocin FIRST)
• Tachysystole = >5 contractions/10min (expected: 3–5 ctx/10min, 30–
🤲 LEOPOLD'S 4 GRIPS
• Cephalohematoma: does NOT cross sutures, resolves 6–8 weeks 40sec each); mgmt = D/C uterotonics ± tocolytic (terbutaline,
nifedipine)
• 1. Fundal — what's in fundus 2. Lateral — locate fetal back 3. • Dystocia goal = restore effective ctx pattern w/ cervical change.
Pawlik's — presenting part/engagement 4. Pelvic — Hypotonic labor: rest/hydration/ambulation ± oxytocin. Hypertonic
labor: rest/sedation — NOT oxytocin. Monitor FHR/ctx continuously,
✋ CONTRACTION ASSESSMENT
attitude/descent
🩹 PERINEAL LACERATION DEGREES
reassess coping/VS, communicate lack of progress to MD
• Frequency = start-to-start · Duration = start-to-end · Intensity =
strength to acme • 1° skin only · 2° perineal muscles · 3° anal sphincter · 4° + anterior
🦠 HIV+ MOTHER
• Palpation: Mild = tip of nose · Moderate = chin · Strong = forehead rectal wall (3°/4° = OASI); occurs in 53–89% of vaginal births
• Effacement: 0%=2cm long, 50%=1cm, 100%=0cm · Dilation: 0cm
closed, 5cm half, 10cm complete • Zidovudine IV over 1h → maintenance infusion to birth; newborn PO
• 4 parts of a contraction: Increment → Acme → Decrement →
💊 LABOR MEDICATIONS
zidovudine q6h x6 weeks
Interval (rest)
💧 ROM / FLUID TESTS
• Resting period between contractions: 2–4 min
• Opioids (Stadol, Nubain, Demerol, morphine, fentanyl): cross
placenta, risk newborn resp. depression → reverse w/ Narcan
• Nitrazine strip → amniotic fluid alkalotic (blue-green) · Fern test → • Antiemetics: given w/ opioids to ↓N/V, potentiate effect
fern pattern under microscope = amniotic fluid • Benzos: sedation; Valium IV also stops eclamptic seizures
• Amniotic fluid color: Clear = normal · Cloudy/foul = infection · Green • Epidural: start when dilation >5cm; watch for maternal hypotension;
= meconium; normal = odorless, thin, clear NPO + bedbound after placement; test dose confirms placement first
• AROM = provider ONLY via amnihook (never nurse) · SROM = • Oxytocin (Pitocin): D/C immediately if tachysystole/late decels; 2
spontaneous · Amnioinfusion = warmed fluid cushions cord (r/o uses = (1) induce/augment labor (2) prevent/treat PPH as uterotonic
prolapse first) • Mag sulfate: tocolytic + seizure prevention; CNS/resp depressant!
• Oligohydramnios = uteroplacental insufficiency/renal issues/leaking Antidote = calcium gluconate
💓 FHR BASICS
fluid · Polyhydramnios = gestational diabetes — BOTH abnormal • RhoGAM: given to Rh-NEGATIVE moms ~28wk & within 72h
postpartum
• Normal baseline: 110–160 bpm, avg over 10min, rounded to nearest • Methergine: PPH/subinvolution — IM, HOLD if hypertensive
5 • Betamethasone: fetal lung maturity ~24–34wk (antenatal
corticosteroid, ↓ neonatal RDS)
⚖️ TRUE VS FALSE LABOR absent/minimal/marked = concerning; >25bpm ("saltatory") =
possible acute hypoxia/cord compression
• Accelerations: ≥15bpm x15sec (15x15) or ≥10bpm x10sec if <32wk
True Labor False Labor • Monitoring freq: Stage 1 active q30min (low)/q15min (high) · Stage 2
Regular, ↑ Irregular, no progression, q15min (low)/q5min (high)
freq/duration/intensity, front/groin only, decreases • Continuous EFM if: oxytocin, epidural, PROM >24h, HTN, delayed
felt all over, worsens w/ w/ activity; no cervical stage 1/2, meconium/possible asphyxia
walking; progressive change • Bradycardia <110x10min → reposition/resuscitate, emergent birth if
cervical change unresolved
🌷 PREMONITORY SIGNS
• Lightening: descent into pelvis ~38–40wk, easier breathing, ↑
• Tachycardia >160x10min → find/treat cause (fever, distress, cardiac,
prematurity)
• Resuscitation steps: reposition, IV bolus, O2, D/C uterotonics → if no
pressure/urinary frequency, leg cramps, edema improvement, prep for birth
• Nesting: energy surge 24–48h before labor • Fetal scalp stimulation = check for FHR acceleration
• Bloody show: mucus plug + pink-tinged discharge • FSE (fetal scalp electrode) = precise internal FHR monitoring; needs
• Braxton Hicks: irregular, decrease w/ activity ROM + dilation
🎀 4 STAGES OF LABOR
• SROM: labor usually starts within 24h; risk = infection/cord prolapse • FHR categories: Cat I = routine (reassuring); Cat II = ↑ surveillance +
corrective measures; Cat III = immediate action → emergent birth if
uncorrected
Stage Key Point • Corrective ladder: reposition (lateral/knee-chest) → IV bolus → O2
1 Latent 0–6cm, mild, q5–10min → D/C oxytocin/uterotonics → amnioinfusion (variable decels, r/o
prolapse first) → fetal scalp stimulation to check for acceleration
1 Active 6–10cm, mod-strong, q2–5min, dilates • Switch to emergent delivery when: Cat III unresolved by corrective
1.2–1.5cm/hr measures, recurrent worsening decels, or prolonged
2 Expulsive Complete dilation → birth, strong q2–
📉 DECELERATIONS
decel/bradycardia doesn't recover
3min
3 Placental Birth → placenta (5–30min)
4 Restorative Placenta → 1–4h; VS q15min Type Cause / Significance
🅿️ 5 P's (+ Additional)
• Passageway, Passenger, Powers, Position, Psychological response
Early Head compression — BENIGN, gradual,
mirrors ctx
Late UPI — gradual, AFTER peak — always
🧭 STATION & POSITION
• + Philosophy, Partners, Patience, Patient prep, Pain management Cat II/III, act now
Variable Cord compression — abrupt V/U/W,
• 0 station = at ischial spines; − above, + below ≥15bpm≥15sec
• Floating = −4 to −1 · Engaged = 0 to +3 · Outlet = +4 Prolonged <60bpm, >2min<10min — OBSTETRIC
• 3-letter code: side + part (O/S/M/A) + A/P/T (e.g., LOA, ROT, LOP) EMERGENCY
🔄 CARDINAL MOVEMENTS
• Engagement = biparietal diameter through pelvic inlet Sinusoidal Smooth wave >20min = severe
distress/anemia
• Engagement → Descent → Flexion → Internal rotation → Extension 🚨 LATE DECEL — ACTION ORDER
👶 SCALP FINDINGS
→ External rotation → Expulsion • 1) Turn to LEFT side 2) O2 3) ↑ IV fluids 4) D/C oxytocin 5) Notify
provider
• Caput succedaneum: crosses sutures, resolves 3–4 days • (If on Pitocin + tachysystole → D/C oxytocin FIRST)
• Tachysystole = >5 contractions/10min (expected: 3–5 ctx/10min, 30–
🤲 LEOPOLD'S 4 GRIPS
• Cephalohematoma: does NOT cross sutures, resolves 6–8 weeks 40sec each); mgmt = D/C uterotonics ± tocolytic (terbutaline,
nifedipine)
• 1. Fundal — what's in fundus 2. Lateral — locate fetal back 3. • Dystocia goal = restore effective ctx pattern w/ cervical change.
Pawlik's — presenting part/engagement 4. Pelvic — Hypotonic labor: rest/hydration/ambulation ± oxytocin. Hypertonic
labor: rest/sedation — NOT oxytocin. Monitor FHR/ctx continuously,
✋ CONTRACTION ASSESSMENT
attitude/descent
🩹 PERINEAL LACERATION DEGREES
reassess coping/VS, communicate lack of progress to MD
• Frequency = start-to-start · Duration = start-to-end · Intensity =
strength to acme • 1° skin only · 2° perineal muscles · 3° anal sphincter · 4° + anterior
🦠 HIV+ MOTHER
• Palpation: Mild = tip of nose · Moderate = chin · Strong = forehead rectal wall (3°/4° = OASI); occurs in 53–89% of vaginal births
• Effacement: 0%=2cm long, 50%=1cm, 100%=0cm · Dilation: 0cm
closed, 5cm half, 10cm complete • Zidovudine IV over 1h → maintenance infusion to birth; newborn PO
• 4 parts of a contraction: Increment → Acme → Decrement →
💊 LABOR MEDICATIONS
zidovudine q6h x6 weeks
Interval (rest)
💧 ROM / FLUID TESTS
• Resting period between contractions: 2–4 min
• Opioids (Stadol, Nubain, Demerol, morphine, fentanyl): cross
placenta, risk newborn resp. depression → reverse w/ Narcan
• Nitrazine strip → amniotic fluid alkalotic (blue-green) · Fern test → • Antiemetics: given w/ opioids to ↓N/V, potentiate effect
fern pattern under microscope = amniotic fluid • Benzos: sedation; Valium IV also stops eclamptic seizures
• Amniotic fluid color: Clear = normal · Cloudy/foul = infection · Green • Epidural: start when dilation >5cm; watch for maternal hypotension;
= meconium; normal = odorless, thin, clear NPO + bedbound after placement; test dose confirms placement first
• AROM = provider ONLY via amnihook (never nurse) · SROM = • Oxytocin (Pitocin): D/C immediately if tachysystole/late decels; 2
spontaneous · Amnioinfusion = warmed fluid cushions cord (r/o uses = (1) induce/augment labor (2) prevent/treat PPH as uterotonic
prolapse first) • Mag sulfate: tocolytic + seizure prevention; CNS/resp depressant!
• Oligohydramnios = uteroplacental insufficiency/renal issues/leaking Antidote = calcium gluconate
💓 FHR BASICS
fluid · Polyhydramnios = gestational diabetes — BOTH abnormal • RhoGAM: given to Rh-NEGATIVE moms ~28wk & within 72h
postpartum
• Normal baseline: 110–160 bpm, avg over 10min, rounded to nearest • Methergine: PPH/subinvolution — IM, HOLD if hypertensive
5 • Betamethasone: fetal lung maturity ~24–34wk (antenatal
corticosteroid, ↓ neonatal RDS)
