Instrumental vaginal birth

What is an instrumental vaginal birth?

It’s a vaginal birth – you still push your baby out – but your obstetrician uses an instrument to give you some help.

There are 2 main instruments we use to help deliver a baby vaginally:

  • A handheld suction cup which goes on the top of baby’s head.  The cup is sometimes called the “vaccuum’” or “Kiwi cup.”
  • The forceps.  These look a bit like big salad tongs!  The forceps are placed over the baby’s ears and cheeks.

Dr Colin Walsh vaginal birth image

Why would I need an assisted vaginal birth?

We all hope for a spontaneous vaginal birth – one where mum gives birth without needing any assistance.  However, it’s not always possible to achieve this safely.  Your obstetrician may need to help for a number reasons, including:

  • Your baby is tired or distressed
  • The baby is lying in an awkward position
  • You’ve been pushing for a long time (more than 1-1.5 hours), which increases the risk of problems such as post-partum bleeding
  • You are exhausted
  • You are developing an infection
  • Some women have underlying medical problems that can be affected by pushing

Why don’t you just do a caesarean in these situations?

In these situations, a caesarean section can be difficult as the baby’s head is very low in the birth canal.  A difficult caesarean section in advanced labour carries more risks for the mother and baby than a planned, pre-labour caesarean. A caesarean may also take longer as you will need to be transferred to an available operating theatre; this delay may be unsafe in some circumstances e.g. if the baby is very distressed. An instrumental vaginal birth can be the quicker and safer option.

Are instrumental vaginal births safe?

Dr Walsh published a landmark scientific study proving the safety of instrumental delivery when performed by an experienced obstetrician [1].

Are all women suitable for an assisted vaginal birth?

The aim of any delivery is a healthy mother and baby.  Sometimes, if the baby is lying too high up the birth canal, or is in distress, an emergency caesarean is the wiser choice.  However, a caesarean late in labour carries its own set of potential complications.

Women need to be pushing well for an instrumental vaginal birth to be successful.  (The obstetrician guides the baby’s head as the woman pushes with a contraction). She should have adequate pain relief (ideally an epidural).  Her cervix must be fully dilated and the obstetrician must work out which way the baby is facing in the birth canal.

Before having an instrumental delivery, the woman should understand why it is being recommended.  However, this doesn’t mean there will always be time to have a detailed discussion – in an emergency, the obstetrician may only have time to tell you very briefly why the instrumental is needed. For this reason, we recommend speaking to your obstetrician or midwife about the different modes of birth during your antenatal care. Aim to go into labour feeling like you understand the different possibilities, in case things need to move quickly on the day.

How do you decide whether to use a vacuum or a forceps?

This depends on a number of things, including:

  • Whether baby is looking down, up or sideways
  • What pain relief the woman is using
  • How high the baby is lying in the birth canal
  • How quickly the baby needs to be delivered
  • Obstetrician preference

Forceps and vaccuum can’t be used equally in all situations.  Having an obstetrician who is experienced in both options, who will choose the right option for you and your baby, is critical.

Are there any risks with an instrumental vaginal birth?

Overall, instrumental vaginal births are safe and the risk of complications is low – the overall rate of complications is similar to an emergency caesarean section in the same situation, although the specific complications vary.

There is a small increase in the chance of a 3rd or 4th degree tear.  To reduce this risk, Dr Walsh almost always makes a small episiotomy when he is performing vacuum or forceps.  He repairs the episiotomy with dissolving stitches and it heals up within a few weeks.

There is an increased risk of pelvic floor problems (incontinence and prolapse) with an instrumental birth compared to a spontaneous vaginal birth or Caesarean section. However, it is important to note that women who have a spontaneous vaginal birth or Caesarean still have significantly higher rates of pelvic floor problems than a woman who has never given birth.

Babies born by instrumental delivery will have either a bump on their head (from the vacuum) or small grazes on their cheeks (from the forceps) – these disappear within a few days.

Rare complications associated with instrumental delivery include:

  • Failed instrumental – the baby cannot be delivered vaginally and a caesarean is necessary
  • Bleeding under the skull bone, which is rare (less than 1 in 500) but serious
  • Compression injury to the baby’s facial nerves which is rare (less than 1%) and usually temporary.

Which is safer?

One instrument is not “better” than the other, rather we use them in different situations.

  • The failure rate is higher with vacuum
  • More babies are jaundiced after vacuum
  • Serious bleeding in the baby’s head is slightly higher after vacuum (but still very rare)
  • 3rd degree tears and pelvic floor problems (incontinence or prolapse) are more common with forceps but still occur with vacuum
  • Facial nerve injury is higher after forceps
  1. Walsh CA et al. Mode of delivery at term and adverse neonatal outcomes. Obstet Gynecol 2013; 121: 122-8.

As always, this information is intended for general educational purposes only. It is not medical advice. Please discuss any medical issues with your own doctor. Read our full medical disclaimer here.