Give me obg labour topics with explanation and after that you ask me neet pg level questions I will try to answer

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🩺 OBG Labour - Complete NEET PG Study Guide

TOPIC 1: NORMAL LABOUR

Definition

Labour is the process by which the fetus, placenta, and membranes are expelled from the uterus through the birth canal. It is considered normal (eutocia) when:

Spontaneous onset at term (37-42 weeks)
Single fetus in vertex presentation
Vaginal delivery within 18 hours
No maternal or fetal complications

Prelabour Signs

Show (Bloody show) - mucus plug discharge with blood
Lightening - descent of fetal head into pelvis (2 weeks before in primis, just before in multis)
Braxton Hicks contractions become regular
Cervical ripening - effacement + softening

True vs False Labour

Feature	True Labour	False Labour
Contractions	Regular, increasing frequency	Irregular
Cervical change	Progressive dilation	No change
Pain location	Back + abdomen	Abdomen only
Effect of sedation	No relief	Relieved
Fetal station	Descends	No descent

TOPIC 2: STAGES OF LABOUR

First Stage - Cervical Dilation

Divided into two phases:

Latent Phase:

Onset of true labour to 3-4 cm dilation
Cervical effacement predominates
Duration: up to 20 hours in primis, 14 hours in multis (Friedman)
Prolonged latent phase: >20 hrs primigravida, >14 hrs multigravida

Active Phase:

4-10 cm dilation
Rate: ≥1.2 cm/hr in primis, ≥1.5 cm/hr in multis (Friedman)
New WHO/ACOG 2014: active phase starts at 6 cm
Prolonged active phase: <1 cm/hr over 2 hours after 6 cm

Deceleration Phase (Friedman's classic):

8-10 cm; descent begins; often omitted in modern classifications

Second Stage - Expulsion

Complete dilation to delivery of baby
Primigravida: up to 2 hours (3 hours with epidural)
Multigravida: up to 1 hour (2 hours with epidural)
Key: active pushing with contractions

Third Stage - Placental

Delivery of baby to delivery of placenta
Normal: within 30 minutes
Retained placenta: not delivered within 30 minutes (some texts 60 min)
Signs of placental separation: Calkin's sign, Küstner sign, Matthews Duncan/Schultze

Fourth Stage

First 1-2 hours post delivery - monitoring for PPH

TOPIC 3: MECHANISM OF LABOUR (Cardinal Movements)

For a vertex presentation in an occipito-anterior (OA) position:

Engagement - BPD passes the pelvic brim; station 0; in primis 2-4 weeks before; multis at onset of labour
Descent - throughout labour; passive at first, active in 2nd stage
Flexion - chin touches chest; suboccipitobregmatic (SOB) diameter presents = 9.5 cm (smallest)
Internal Rotation - occiput rotates from transverse to OA (AP); occurs at ischial spines level
Extension - head delivered by extension under pubic symphysis; suboccipitofrontal diameter sweeps the perineum
Restitution - head rotates back to its original oblique position (undoing internal rotation)
External Rotation (Shoulder rotation) - shoulders rotate into AP diameter; head turns further
Expulsion - anterior shoulder under pubic arch, posterior shoulder delivered, rest of body follows

Memory aid: "Every Dumb F-witted I-diot Enters Restitution Externally" Engagement, Descent, Flexion, Internal rotation, Extension, Restitution, External rotation

TOPIC 4: PARTOGRAPH

The WHO partograph is the graphical record of labour progress.

Alert Line: Normal rate of descent/dilation. Starts at 4 cm (active phase onset), drawn at rate of 1 cm/hr.

Action Line: 4 hours to the right of the alert line. Crossing this = intervention needed.

Components recorded:

Fetal heart rate (every 30 min in 1st stage, every 5 min in 2nd stage)
Liquor (C = clear, M = meconium, B = blood, A = absent)
Moulding (0, +, ++, +++)
Cervical dilation
Descent (fifths of head palpable abdominally)
Contractions per 10 min (duration and frequency)
Oxytocin, drugs, IV fluids
Maternal vitals

TOPIC 5: INDUCTION OF LABOUR (IOL)

Definition: Artificially initiating uterine contractions before spontaneous onset.

Indications:

Post-term pregnancy (≥41-42 weeks)
PROM/PPROM
PIH/Pre-eclampsia/Eclampsia
Diabetes complicating pregnancy
IUGR with Doppler abnormalities
Rh isoimmunization
IUD

Bishop Score (Cervical favourability):

Parameter	0	1	2	3
Dilation (cm)	0	1-2	3-4	≥5
Effacement (%)	0-30	40-50	60-70	≥80
Station	-3	-2	-1/0	+1/+2
Consistency	Firm	Medium	Soft	-
Position	Posterior	Mid	Anterior	-

Score ≥8: favourable cervix, IOL likely successful without ripening
Score <6: cervical ripening needed

Cervical Ripening Agents:

Dinoprostone (PGE2): gel, pessary, vaginal insert
Misoprostol (PGE1): 25 mcg vaginally or 50 mcg orally (most commonly used in practice)
Mechanical: Foley catheter (30 mL balloon), hygroscopic dilators (laminaria)

Methods of IOL:

Surgical: ARM (AROM) - amniotomy; most effective when cervix is favourable
Medical: Oxytocin IV infusion; starts at 1-2 mU/min, doubled every 30-60 min
Membrane sweeping (stripping): mechanical stimulation; prostaglandin release

Contraindications to IOL:

Placenta previa, vasa previa
Previous classical C-section
Active herpes
Cord presentation
Transverse lie

TOPIC 6: ABNORMAL LABOUR (DYSTOCIA)

The 3 Ps: Powers, Passenger, Passage

Prolonged Labour Patterns

Disorder	Definition
Prolonged latent phase	>20 hr primigravida, >14 hr multigravida
Arrest of active phase	No dilation for ≥4 hrs with adequate contractions (or ≥6 hrs with inadequate)
Protracted active phase	<1 cm/hr (primis) or <1.5 cm/hr (multis)
Arrest of descent	No descent for ≥1 hr (primis) or ≥30 min (multis) in 2nd stage
Prolonged 2nd stage	>3 hrs primis (with epidural), >2 hrs without; >2 hrs multis with, >1 hr without

Cephalopelvic Disproportion (CPD)

Fetal head too large relative to pelvic capacity
Diagnosed when: adequate contractions, no progress, head not engaged
Management: C-section

Uterine Atony (common cause of failure of powers)

Treat with oxytocin, ergometrine, misoprostol, carboprost

TOPIC 7: COMPLICATIONS OF LABOUR

Postpartum Hemorrhage (PPH)

Primary PPH: >500 mL blood loss within 24 hours (>1000 mL after C-section)
Causes - 4 Ts: Tone (80%), Trauma, Tissue, Thrombin

Uterotonic Drugs:

Oxytocin: 1st line, 10 IU IM or IV infusion
Ergometrine: contraindicated in hypertension
Carboprost (15-methyl PGF2α): contraindicated in asthma
Misoprostol: 800 mcg rectally
Tranexamic acid: within 3 hours of delivery (WOMAN trial)

Surgical options: B-Lynch suture, uterine artery ligation, internal iliac artery ligation, hysterectomy

Shoulder Dystocia

Anterior shoulder impacted behind pubic symphysis after head delivery
Incidence: 0.6-1.4%
HELPERR mnemonic:
- H - Call for Help
- E - Evaluate for Episiotomy
- L - Legs (McRoberts maneuver) - thighs hyperflexed on abdomen (most effective first step)
- P - Suprapubic Pressure
- E - Enter (internal rotational maneuvers - Rubin II, Woods screw)
- R - Remove the posterior arm
- R - Roll the patient (Gaskin all-fours position)
Complications: Erb's palsy (C5-C6), brachial plexus injury, clavicle fracture, HIE

Cord Prolapse

Umbilical cord descends below the presenting part after membranes rupture
Emergency: fetal bradycardia/distress
Management: lift presenting part off cord, fill bladder with 500 mL saline, knee-chest position, EMERGENCY C-SECTION

Meconium-Stained Liquor (MSL)

Thin MSL: <37 weeks normal; >37 weeks watch carefully
Thick MSL: suggests fetal distress
Management: continuous EFM; paediatrics team at delivery for neonatal resuscitation
Meconium aspiration syndrome (MAS) - intrapartum or postnatal suctioning no longer routinely recommended (ILCOR 2015)

Uterine Rupture

Scar rupture: most common (previous C-section)
Signs: sudden cessation of contractions, fetal bradycardia, abdominal pain between contractions, loss of fetal station, haematuria
Silent/Complete vs Incomplete rupture
Management: emergency laparotomy

TOPIC 8: FETAL MONITORING IN LABOUR

CTG Interpretation (Cardiotocography)

Normal parameters:

Baseline FHR: 110-160 bpm
Baseline variability: 5-25 bpm
Accelerations: ≥15 bpm above baseline for ≥15 sec
Decelerations: nil or early

Decelerations:

Type	Timing	Cause	Significance
Early	Mirrors contraction	Head compression	Benign
Late	After contraction peak	Uteroplacental insufficiency	Pathological
Variable	Variable timing	Cord compression	Moderate concern
Prolonged	>2 min	Various	Concerning

Classification (NICE):

Normal: all 4 features reassuring
Suspicious: 1 non-reassuring feature
Pathological: 2+ non-reassuring OR 1 abnormal feature → fetal blood sampling or delivery

Fetal Blood Sampling (FBS)

pH >7.25: Normal → continue
pH 7.21-7.24: Borderline → repeat in 30 min
pH <7.20: Abnormal → deliver immediately

TOPIC 9: OPERATIVE VAGINAL DELIVERY

Forceps

Used when: full dilation, engaged head, vertex/face, adequate pelvis, empty bladder
Types: Simpson (outlet), Kjelland (rotation), Piper (aftercoming head)
Pre-requisites: CAVE - Cervix fully dilated, Analgesia, Vertex presentation, Empty bladder

Vacuum (Ventouse)

Cup applied to flexion point (3 cm anterior to posterior fontanelle)
Maximum pulls: 3 in a contraction, total traction time <15-20 min
Contraindicated <34 weeks, face presentation, active bleeding disorder

C-Section Indications (Absolute)

CPD, placenta previa, cord prolapse with live fetus, transverse lie, previous classical C-section, active genital herpes

TOPIC 10: PRETERM LABOUR

Definition: Onset of labour <37 completed weeks
Extreme preterm: <28 weeks; Very preterm: 28-32 weeks; Moderate/Late preterm: 32-37 weeks

Diagnosis

Regular contractions + cervical change <37 weeks
Cervical length <25 mm on TVS at 24 weeks = high risk
Fetal Fibronectin (fFN): negative result highly reassuring; positive = 7-fold increased risk

Tocolytics (delay delivery 48 hrs for steroids)

Nifedipine (CCB): 1st line oral tocolytic
Atosiban (oxytocin antagonist): 1st line in Europe; fewer side effects
Terbutaline/Ritodrine (beta-2 agonists): tachycardia, hyperglycemia
Indomethacin: <32 weeks; risk of premature closure of DA
MgSO4: NOT for tocolysis - used for neuroprotection <32 weeks (reduces cerebral palsy)

Corticosteroids

Betamethasone 12 mg IM × 2 doses 24 hr apart (preferred)
Dexamethasone 6 mg IM × 4 doses 12 hr apart
Given at 24-34 weeks; reduces RDS, IVH, NEC
Single rescue course if >2 weeks after first course and <34 weeks

✅ NOW - NEET PG QUESTIONS

We will go topic by topic. I'll give you 5 questions per topic.

📝 TOPIC 1: NORMAL LABOUR - Questions

Q1. A 24-year-old primigravida at 39 weeks presents with regular painful uterine contractions every 5 minutes. On examination, the cervix is 3 cm dilated, 80% effaced, station -1. 8 hours later, her cervix is still 3 cm. What is the most likely diagnosis?

a) False labour b) Prolonged latent phase c) Arrest of active phase d) Secondary arrest

Q2. Which of the following is the MOST reliable sign that distinguishes true labour from false labour?

a) Regular contractions b) Progressive cervical dilation c) Pain in the back d) Show (bloody mucus discharge)

Q3. A multigravida at 38 weeks has a "show" 10 days before her expected delivery. She is not in labour. What is the "show"?

a) Rupture of membranes b) Expulsion of the mucus plug c) Placental bleeding d) Vasa previa bleeding

Q4. The latent phase of labour in a primigravida is prolonged if it lasts more than:

a) 8 hours b) 12 hours c) 18 hours d) 20 hours

Q5. Which statement about the fourth stage of labour is CORRECT?

a) It lasts 6-12 hours b) It ends with delivery of the placenta c) It is the first 1-2 hours after delivery of the baby d) Hemorrhage risk is lowest in this stage

Take your time and answer Q1-Q5. Write your answers as a/b/c/d. After you answer, I'll give you the correct answers with explanations and move to Topic 2! 🎯

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