Abnormal Labour in Obstetrics

Definition and Incidence

• Abnormal labour: a labour that deviates from the normal pattern of progression, making it difficult or impossible to achieve a vaginal delivery without complications.
• Incidence: 10-20% of all labours, but can be as high as 30% in nulliparous women.

Types of Abnormal Labour

• Prolonged Labour: labour that lasts longer than expected, usually > 12 hours in nulliparous women and > 6 hours in multiparous women.
• Arrest of Labour: labour that fails to progress despite adequate uterine contractions, usually due to cephalopelvic disproportion (CPD) or fetal malposition.
• Secondary Arrest: labour that progresses initially but then arrests, often due to fetal distress or uterine exhaustion.

Causes of Abnormal Labour

• Fetal Factors:
  • Fetal macrosomia or growth restriction
  • Fetal malposition or anomalies
  • Fetal distress or compromise
• Maternal Factors:
  • Uterine anomalies or scarring
  • Weak or ineffective uterine contractions
  • Obesity or other medical conditions
• Mechanical Factors:
  • Cephalopelvic disproportion (CPD)
  • Placenta previa or low-lying placenta
  • Umbilical cord prolapse

Diagnosis and Management

• Diagnosis: based on clinical evaluation, including vaginal examinations, fetal monitoring, and ultrasound assessment.
• Management: depends on the type and severity of abnormal labour, and may include:
  • Oxytocin augmentation or induction
  • Fetal monitoring and surveillance
  • Instrumental delivery (forceps or vacuum extraction)
  • Caesarean section
  • Intrapartum fetal resuscitation techniques

Complications and Risks

• Maternal Complications:
  • Uterine rupture or dehiscence
  • Postpartum haemorrhage (PPH)
  • Infection or sepsis
• Fetal Complications:
  • Fetal distress or asphyxia
  • Fetal injury or trauma
  • Neonatal respiratory depression or distress

Definition and Incidence

• Abnormal labour is a labour that deviates from the normal pattern of progression, making it difficult or impossible to achieve a vaginal delivery without complications.
• Incidence of abnormal labour is 10-20% of all labours, but can be as high as 30% in nulliparous women.

Types of Abnormal Labour

• Prolonged labour is when labour lasts longer than expected, usually > 12 hours in nulliparous women and > 6 hours in multiparous women.
• Arrest of labour occurs when labour fails to progress despite adequate uterine contractions, usually due to cephalopelvic disproportion (CPD) or fetal malposition.
• Secondary arrest is when labour progresses initially but then arrests, often due to fetal distress or uterine exhaustion.

Causes of Abnormal Labour

• Fetal macrosomia or growth restriction can cause abnormal labour.
• Fetal malposition or anomalies can cause abnormal labour.
• Fetal distress or compromise can cause abnormal labour.
• Uterine anomalies or scarring can cause abnormal labour.
• Weak or ineffective uterine contractions can cause abnormal labour.
• Obesity or other medical conditions can cause abnormal labour.
• Cephalopelvic disproportion (CPD) can cause abnormal labour.
• Placenta previa or low-lying placenta can cause abnormal labour.
• Umbilical cord prolapse can cause abnormal labour.

Diagnosis and Management

• Diagnosis of abnormal labour is based on clinical evaluation, including vaginal examinations, fetal monitoring, and ultrasound assessment.
• Management of abnormal labour depends on the type and severity of abnormal labour, and may include oxytocin augmentation or induction.
• Fetal monitoring and surveillance are used in managing abnormal labour.
• Instrumental delivery (forceps or vacuum extraction) may be used in managing abnormal labour.
• Caesarean section may be used in managing abnormal labour.
• Intrapartum fetal resuscitation techniques are used in managing abnormal labour.

Complications and Risks

• Uterine rupture or dehiscence can be a complication of abnormal labour.
• Postpartum haemorrhage (PPH) can be a complication of abnormal labour.
• Infection or sepsis can be a complication of abnormal labour.
• Fetal distress or asphyxia can be a complication of abnormal labour.
• Fetal injury or trauma can be a complication of abnormal labour.
• Neonatal respiratory depression or distress can be a complication of abnormal labour.