labor- exam 1

Four Stages of Labor

1st: true labor → 10 cm (progress + fetal tolerance). 2nd: 10 cm → birth (descent + pushing). 3rd: birth → placenta (placental separation). 4th: immediate recovery (maternal stabilization).

Uncomplicated Labor

Labor progresses AND maternal patient + fetus tolerate the process. Progress = cervical change + descent; maternal tolerance = stable assessment + expected physiologic response; fetal tolerance = reassuring response to contractions.

Preparing for Labor: Expected Changes

Lightening; ↑ discharge/bloody show; Braxton Hicks may increase.

True Labor

Regular contractions + progressive cervical change. Progressive cervical change establishes true labor.

5 P's of Labor

Passage = pelvis + soft tissues; Passenger = fetal size + alignment; Powers = contractions + pushing; Position = maternal movement; Psyche = coping + support. If labor stalls, assess which P may be interfering.

Fetal Lie

Lie = fetal spine relative to maternal spine; helps determine whether fetus is aligned to enter pelvis.

Fetal Presentation

Presentation = fetal part entering pelvis first. Most favorable alignment = longitudinal + vertex.

Fetal Attitude

Relationship of fetal parts to one another; flexion generally supports descent.

Fetal Position

Presenting part relative to maternal pelvis; OA generally supports descent.

Station + Engagement

Station = presenting part relative to ischial spines. 0 = engaged; negative = above; positive = below. Trend over time shows descent.

Favorable Passenger Pattern

Longitudinal → vertex → flexion → OA → progressive descent.

Passageway

Bony pelvis + soft tissues form passageway; cervical dilation + effacement make pathway available for descent. If labor isn't progressing, passageway is one possible contributor—not the only explanation.

Primary vs. Secondary Powers

Primary = involuntary uterine contractions causing effacement, dilation, descent. Secondary = voluntary maternal pushing after full dilation during 2nd stage. Contractions first → pushing only after full dilation.

Contraction Frequency

Beginning of one contraction → beginning of next.

Contraction Duration

Beginning → end of one contraction.

Contraction Intensity + Resting Tone

Intensity = contraction strength; resting tone = relaxation between contractions. Effective contractions create change AND allow uterine recovery.

Dilation + Effacement

Dilation = cervical opening 0-10 cm; effacement = cervical thinning/shortening 0-100%.

Assessing Labor Progress

Use dilation + effacement + station + contraction pattern over time. One exam = snapshot; serial exams = progression. Also consider membranes, bleeding, infection risk, and fetal status.

Maternal Admission Risk Scan

Stability: vital signs + appearance. Labor status: contractions, membranes, bleeding. Patient context: pain, coping, support, preferences. History: pregnancy history, meds, allergies.

Assessing Fetal Tolerance on Admission

Assess gestational age + movement; FHR baseline + pattern; presentation + descent; membranes + fluid. Labor progress and fetal tolerance are assessed together.

Admission Labs & Screens

GBS = intrapartum prophylaxis; blood type/Rh = blood/Rh considerations; CBC = baseline Hgb/Hct + platelets; HIV/HBsAg = maternal/newborn management; rubella immunity = postpartum immunization planning; STI screens = treatment + newborn implications.

Maternal Adaptations During Labor

Cardiovascular: ↑ cardiac output; HR/BP may change with contractions. Respiratory: ↑ O₂ demand; anxiety may cause hyperventilation. GI: slower gastric emptying; nausea/vomiting. Urinary: full bladder can interfere with descent. Hematologic: leukocytosis may occur; blood loss anticipated with birth.

Interpreting Expected Maternal Changes

Expected ≠ ignore. Interpret severity, timing, associated cues, and trends.

Why Fetal Monitoring Matters

Contractions temporarily ↓ uteroplacental blood flow; perfusion should recover between contractions. FHR patterns show fetal tolerance of labor stress.

Intermittent Auscultation

Periodic FHR assessment; supports mobility; used for selected low-risk patients.

Electronic Fetal Monitoring

Displays FHR + uterine activity; external or internal methods; interpret overall pattern.

External vs. Internal Fetal Monitoring

External = noninvasive; FHR + contraction pattern. Internal = direct information when indicated; requires specific clinical conditions. Choose based on information needed.

FHR Strip Interpretation Order

Baseline → variability → accelerations → decelerations. Then interpret → nursing action → evaluate.

FHR Baseline

Expected = 110-160 bpm; interpret with entire pattern, trend, and maternal cues.

FHR Variability

Fluctuations around baseline; moderate variability is reassuring. Interpret in full clinical picture.

FHR Accelerations

Generally reassuring; interpret with entire pattern.

Early Decelerations

Gradual decrease mirroring contraction; caused by fetal head compression; often accompanies labor progress. Nursing focus: continue assessment + monitor overall pattern. EARLY = HEAD.

Variable Decelerations

Abrupt drops with varying timing/shape; likely umbilical cord compression. Reposition to reduce compression; persistent/recurrent variables require continued assessment + escalation as indicated. VARIABLE = CORD.

Late Decelerations

Begin after contraction onset, nadir after peak, recover after contraction ends; associated with uteroplacental insufficiency. Persistence changes priority. LATE = PLACENTA.

Fetal Bradycardia

Baseline

Fetal Tachycardia

Baseline >160 bpm. Assess fever/infection, dehydration, medications, fetal stress, and full tracing.

Category I FHR

Reassuring: normal baseline + moderate variability; no recurrent late/variable decels → routine surveillance.

Category II FHR

Indeterminate: does not meet Category I or III → evaluate + continue surveillance.

Category III FHR

Abnormal: absent variability with concerning recurrent pattern/bradycardia OR sinusoidal → prompt evaluation/intervention.

FHR Priority Change

A change in fetal tolerance can become the priority even if labor is progressing normally; identify which cue changes the clinical picture.