Labor and Delivery Stages

• Labor and delivery refer to the physiological process by which a pregnant woman expels one or more newborn(s)
• Normal spontaneous delivery (NSD) indicates a vaginal delivery that progresses without the need for medical interventions

Stages of Labor

• Labor is divided into three main stages: the first stage (divided into latent and active phases), the second stage (expulsion of the fetus), and the third stage (expulsion of the placenta)

First Stage of Labor

• Begins with the onset of regular uterine contractions and ends with complete cervical dilatation (10 cm)
• Longest stage, especially for nulliparous women (those who have not previously given birth)

Latent Phase

• Initial phase of the first stage
• Characterized by irregular, mild to moderate contractions
• Cervical effacement (thinning) and dilatation (opening) occur slowly, typically up to 6 cm
• Duration is variable, and can last for hours or even days

Active Phase

• Characterized by more frequent, regular, and intense contractions
• Cervical dilatation progresses more rapidly, from 6 cm to 10 cm
• Typically lasts for several hours

Second Stage of Labor

• Begins with complete cervical dilatation (10 cm) and ends with the delivery of the baby
• Divided into two phases: passive and active

Passive Phase

• Period from complete cervical dilatation until the woman has a strong urge to push
• Fetus descends passively through the birth canal

Active Phase

• Begins when the woman starts actively pushing with each contraction
• Contractions are strong and frequent
• Continues until the baby is delivered

Third Stage of Labor

• Begins immediately after the delivery of the baby and ends with the expulsion of the placenta and membranes
• Usually lasts from 5 to 30 minutes

Mechanisms of Labor

• Cardinal movements of labor are a series of positional changes the fetus undergoes as it passes through the birth canal during delivery including: engagement, descent, flexion, internal rotation, extension, external rotation (restitution), and expulsion

Engagement

• Occurs when the fetal presenting part (usually the head) enters the pelvic inlet
• In nulliparous women, engagement often occurs before the onset of labor

Descent

• Downward movement of the fetal presenting part through the pelvis
• Occurs throughout labor

Flexion

• Fetal head flexes, bringing the chin closer to the chest
• Allows the smallest diameter of the fetal head to present to the pelvis

Internal Rotation

• Fetal head rotates to align the sagittal suture with the anteroposterior diameter of the pelvis

Extension

• As the fetal head reaches the perineum, it extends, allowing the head to be born

External Rotation (Restitution)

• After the head is delivered, it rotates externally to align with the shoulders

Expulsion

• After the external rotation, the anterior shoulder is delivered, followed by the posterior shoulder, and then the rest of the body

Pain Management During Labor

• Non-pharmacological methods include:
  • Breathing techniques
  • Relaxation techniques
  • Massage
  • Hydrotherapy
• Pharmacological methods include:
  • Epidural analgesia
  • Opioids

Monitoring During Labor

• Continuous or intermittent monitoring of the fetal heart rate to assess fetal well-being
• Monitoring of uterine contractions

Interventions During Labor

• Amniotomy (artificial rupture of membranes) is sometimes performed to augment labor
• Oxytocin can be administered to stimulate uterine contractions if labor is not progressing adequately
• Episiotomy (surgical incision of the perineum) may be performed to enlarge the vaginal opening
• Assisted vaginal delivery, using vacuum extraction or forceps, may be necessary if the second stage of labor is prolonged or if there are concerns about fetal well-being

Postpartum Care

• Monitoring of vital signs
• Assessment of uterine involution (return of the uterus to its pre-pregnancy state)
• Monitoring for postpartum bleeding
• Pain management

This covers the stages of labor, including the latent and active phases of the first stage. It explains the physiological process of childbirth and the progression of labor from the onset of contractions to cervical dilation. Normal spontaneous delivery (NSD) is also discussed.