Sometimes during the pushing stage of labour, your midwife in collaboration with the obstetric team may advise that your baby needs to be born quickly. If your baby is low enough in your pelvis, then the quickest way to be born may involve the use of instruments to pull baby out.
Instrumental birth is usually offered when foetal monitoring (Doppler or CTG) indicates that your baby is dropping their heart rate and not recovering well after contractions, or that their heart rate is rising. These may be indicators that your baby is no longer coping well with labour. Foetal monitoring is not an exact science, and some babies that show these indicators are born healthy, but others will show signs that they really needed assistance at birth. If your baby is showing indicators that they are not coping well with labour, you may be offered foetal blood sampling to help guide decision making.
If your care team recommend instrumental birth, there are a few different tools they can offer. What is offered depends on what is available at the hospital you are at, and the skill set of the doctor who is attending you. The two main types of instrument that can be used are grouped into vacuum cups and forceps.
Before you have an assisted birth, you will need to be catheterised (have a soft plastic tube inserted into your bladder to empty it) as assisted birth with a full bladder can cause damage.
No matter which instrument the doctor chooses, they will work with your contractions and pull during a contraction. You will also usually be asked to push while they pull.
Vacuum cups
There are two types of vacuum cup that can be offered – the ‘KiwiCup’, which is a plastic cup that creates suction through a hand held pump, and a ventouse, which is a metal cup that is connected to a machine to create suction. KiwiCup use is far more common than ventouse currently, but it depends on the doctor attending you and their experience of different devices.
The principle behind a vacuum cup is that the doctor applies the cup to baby’s head and engages the suction, and then they pull on the cup to bring baby lower into your pelvis and out your vagina. Some doctors will cut an episiotomy to try and prevent severe tears, although evidence on how well this works is mixed.
The vacuum cup may pop off baby’s head during the process and be reapplied as needed.
Vacuum devices generally cause less damage to the birthing person’s vagina than forceps, but they will usually leave bruising on baby’s head in a distinctive round shape.
Forceps
Forceps are a pair of spoon-shaped metal instruments that fit around baby’s head to pull them down your birth canal and out your vagina. They are inserted one at a time into your vagina, around baby’s head, and then locked together to pull baby out.
There are different types of forceps available, and the type chosen will depend on where your baby is in your pelvis and what the obstetric doctor is familiar with using. Forceps are used less often than suction devices, but are very effective.
Most doctors will recommend an episiotomy before inserting forceps to make room for the instruments to be inserted.
After an assisted birth
You will be recommended to have active management of the birth of your whenua/placenta as the intervention in your birth means that the hormone cascades needed for a physiological birth of the whenua may not work as well.