Indications for Cesarean Birth

In British Columbia, during 2007-2008, the main reasons for cesarean birth were:

  • Repeat cesarean birth (planned cesarean birth after having had a previous cesarean birth)
  • Labour dystocia (also referred to as ‘failure to progress’, or ‘cephalopelvic disproportion’)
  • Fetal distress or non-reassuring fetal heart rate

While repeat cesarean accounts for the most cesarean births overall, labour dystocia and fetal distress are the most common indications for primary (first) cesarean birth.

Repeat Cesarean Birth

In B.C., repeat cesarean birth accounted for 22.2% of all cesareans, or over 3,000 births in 2007. Among women with a previous cesarean, 75% were eligible* for a vaginal birth after cesarean (VBAC), however only 27% of these women planned to have a VBAC. Among those women attempting a VBAC, 70.8% had a vaginal birth.

*Perinatal Services BC describes women as ‘eligible’ for a VBAC if they have the following characteristics: term pregnancy (at least 37 weeks gestation); single baby; and cephalic presentation at delivery. [Source: Perinatal Health Report 2008.]

In 2000, rates of planned vaginal birth ranged from 33% to 50% in BC. In 2005 this ranged changed to 11% to 30%.


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Optimal Birth Evidence Review: Risks of VBAC compared to planned repeat cesarean birth

Labour Dystocia

The most common indication for primary cesarean birth in British Columbia is labour dystocia, or non-progressive labour. Cesarean section due to dystocia accounted for 19.2% of all cesarean sections, or 2,607 births in 2007. Clinical guidelines for the diagnosis and management of dystocia are not consistently followed in Canada.

[Reference: Oppenheimer, L., Holmes, P., Yang, O., Yang, T., Walker, M., & Wen, S. Adherence to guidelines on the management of dystocia and cesarean section rates. American Journal of Perinatology. 2007; 24(5): 271-276.]

Labour that is not progressing normally may be augmented with synthetic oxytocin. In 2005, rates of oxytocin augmentation ranged from 6.5% to 16.2% in hospitals with more than 1,000 births across BC.

Augmentation: Oxytocin (Labouring Mothers)
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Optimal Birth Evidence Review: Definition and diagnosis of dystocia.

Non-reassuring Fetal Heart Rate or Fetal distress

The second most common indication for primary cesarean birth in British Columbia is non-reassuring fetal heart rate or fetal distress. Cesarean section for fetal distress accounted for 13.3% of all cesarean sections in 2007, or 1,812 births.

Among babies delivered by cesarean for non-reassuring fetal heart rates, a range of 5.9% to 45% had a low Apgar score ( <7 out of 10) across BC.

Proportion of 1 min. Apgar < 7 with C/S Indication “Fetal Compromise”
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Other practices that have been shown to be associated with cesarean birth are:

 

  • Admission to hospital before labour is established (See Optimal Birth Evidence Review: Triage).
  • Epidural analgesia (See Optimal Birth Evidence Review: Epidural).
  • Induction of labour for prolonged pregnancy (“post dates”) prior to 41 weeks gestation.