Abnormal Labour in Obstetrics

Study Notes

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.

Description

This quiz covers the definition and incidence of abnormal labour, including prolonged labour and arrest of labour. Learn about the complications and vaginal delivery challenges associated with abnormal labour.