1. Definition of Labor
Labor is the process of uterine contractions leading to progressive cervical dilation and delivery of the fetus and placenta.
- Normal Labor (Eutocia): Spontaneous, at term (37–42 weeks), with a cephalic presentation.
- Abnormal Labor (Dystocia): Prolonged or obstructed labor.
2. Stages of Labor
|
Stage |
Definition |
Duration
(Primigravida) |
Duration
(Multigravida) |
|
First Stage |
Onset of labor → Full cervical dilation (10 cm) |
10–16 hours |
6–8 hours |
|
Second Stage |
Full dilation → Delivery of baby |
1–2 hours |
30 min – 1 hour |
|
Third Stage |
Delivery of baby → Expulsion of placenta |
5–15 min |
5–10 min |
|
Fourth Stage |
First 1–2 hours postpartum
(Monitoring phase) |
- |
- |
3. First Stage of Labor
Latent Phase (0–4 cm dilation):
- Mild, irregular contractions (Every 5–10 minutes, lasting 30 sec).
- Cervical effacement & softening begins.
- Duration: Up to 8–10 hours (Primigravida), 5–6 hours (Multigravida).
Active Phase (4–10 cm dilation):
- Strong, regular contractions (Every 2–3 minutes, lasting 45–60 sec).
- Rapid cervical dilation (>1 cm/hour in Primigravida, >1.5 cm/hour in Multigravida).
- Fetal descent begins.
Prolonged First Stage:
- Cervical dilation <1 cm/hour (Primigravida), <1.5 cm/hour (Multigravida).
- Causes: Cephalopelvic disproportion (CPD), Uterine dysfunction.
- Management: Oxytocin augmentation or Cesarean Section if needed.
4. Second Stage of Labor
- Begins at Full Dilation (10 cm) → Ends with Delivery of Baby.
- Fetal Descent & Expulsion.
- Maternal Pushing Efforts Are Crucial.
Clinical Signs of Second Stage:
- Urge to push (Ferguson reflex).
- Perineal bulging & crowning (fetal head visible).
Prolonged Second Stage:
- >2 hours in Primigravida, >1 hour in Multigravida.
- Causes: Fetal malposition, CPD, Weak maternal efforts.
- Management: Assisted delivery (Vacuum/Forceps) or Cesarean Section.
5. Third Stage of Labor
- Begins after Baby is Delivered → Ends with Placenta Expulsion.
- Placental Separation & Delivery (Within 5–15 min).
Signs of Placental Separation (Schultze Mechanism):
- Gush of blood.
- Lengthening of umbilical cord.
- Fundus becomes firm & rises.
Active Management (Reduces PPH Risk):
- Oxytocin Injection (10 IU IM).
- Controlled Cord Traction (CCT).
- Uterine Massage.
Retained Placenta:
- Placenta not expelled within 30 min.
- Risk of postpartum hemorrhage (PPH).
- Management: Manual removal or surgical intervention.
6. Fourth Stage of Labor
- First 1–2 hours postpartum → Monitoring phase for complications.
- Monitor for Postpartum Hemorrhage (PPH), Uterine Atony, Hypotension.
- Encourage Skin-to-Skin Contact & Breastfeeding.
7. Mechanism of Labor (Cardinal Movements of Labor)
Fetal movements help the baby navigate through the birth canal.
|
Movement |
Description |
|
Engagement |
Head enters the pelvic inlet (At 0 station). |
|
Descent |
Head moves downward due to contractions. |
|
Flexion |
Chin tucks toward chest for a smaller diameter. |
|
Internal Rotation |
Head rotates to align with maternal pelvis (Occiput
anterior). |
|
Extension |
Head extends to pass under pubic symphysis. |
|
External Rotation
(Restitution) |
Head realigns with shoulders. |
|
Expulsion |
Baby's body is delivered. |
- Most common presentation: Occiput Anterior (OA).
- Abnormal positions (OP, OT) can cause prolonged labor.
8. Summary Table: Labor Stages & Cardinal Movements
|
Stage |
Key Features |
Duration |
|
First Stage |
Cervical dilation (0–10 cm) |
10–16 hrs (Primi), 6–8 hrs (Multi) |
|
Second Stage |
Full dilation → Baby delivery |
1–2 hrs (Primi), 30–60 min (Multi) |
|
Third Stage |
Placental expulsion |
5–15 min |
|
Fourth Stage |
Monitoring postpartum recovery |
1–2 hrs |
|
Cardinal Movements |
Engagement, Descent, Flexion, Rotation, Extension,
Expulsion |
Throughout labor |
9. Key Takeaways
- Labor has 4 stages: Cervical dilation, Fetal expulsion, Placenta delivery, Recovery.
- First stage (Active phase) progresses at ~1 cm/hr (Primi) & ~1.5 cm/hr (Multi).
- Second stage requires maternal pushing & ends with baby’s birth.
- Cardinal movements guide the fetus through the birth canal.
- Active management of the third stage prevents postpartum hemorrhage.
