Instrumental Assisted Delivery
Most births occur without the need for an obstetrician to assist the passage of the baby through the birth canal. However, in some cases, an obstetrician may need to use an instrument to help the birth process.
During an instrument-assisted delivery, the obstetrician uses either forceps or vacuum-assistance (also called “Ventouse”). Both forceps and vacuum-assisted deliveries are considered to be acceptable methods when performed by doctors trained in obstetrics.
About one in every 10 vaginal births in Australia and New Zealand is instrument assisted. Vacuum assistance is more commonly used.
Reasons For Instrument-Assisted Delivery
- Baby not making progress through the birth canal, despite pushing by mother
- Baby showing signs of distress, and its heart rate is not normal
- The mother is exhausted and needs assistance with delivery; her well-being and energy for pushing are declining
- The mother has had an epidural to relieve pain; while an epidural can make it difficult for the mother to push as effectively during the second stage of labour, most women can achieve a spontaneous birth
- Baby is in a position that makes it difficult for the baby to pass through the birth canal
- The mother has a pre-existing medical condition that has worsened during labour
- To assist the delivery of the head when the baby is in breech (bottom first) position, though not all breech babies require an instrument-assisted delivery.
Local anaesthesia may be required for vacuum-assisted deliveries. For forceps delivery, regional anaesthesia (spinal anaesthesia or epidural anaesthesia) is usually preferred by the obstetrician.
The obstetrician may need to make a small cut in the perineum, the tissue between the vagina and anus. This enables easier passage of the baby and usually prevents tearing of the tissues, particularly towards the anus. Appropriate local or regional anaesthesia will usually be in place prior to the incision.
Risk of Instrumental Delivery
Risks associated with instrument-assisted delivery include those of normal delivery and:
- Bruising of the baby’s face or scalp, which usually resolves within several days
- Injury to a facial nerve of the baby, which usually resolves
- Injury to the baby’s scalp
- A collection of blood between the scalp and the skull. This is more common with vacuum assistance and does not affect or involve the brain
- Fracture of the baby’s skull
- Spinal cord injury to the baby
- Some blood vessels at the back of the baby’s eye may burst
- Compression of the umbilical cord by the forceps
- Brain haemorrhage in the baby; this is more likely to occur in babies where vacuum assistance or forceps have failed. Therefore, an instrument-assisted delivery is not attempted when the likelihood is low.