No one wants a serious tear in childbirth, and with rising rates of 3rd and 4th degree tears, a new set of guidelines was introduced aiming to prevent these sometimes life changing tears in childbirth. The OASI bundle (obstetric anal sphincter injury) bundle is a set of guidelines to be used by midwives to prevent serious tears. These types of tears are ones that go through the perineal and anal muscles.
What are the OASI guidelines?
The OASI bundle encourages:
preemptive episiotomy as baby’s head is born
hands on approach to the perineum (hand on baby’s head to control the speed it’s born, pressure on the perineum, and using fingers to help presenting parts of baby to be birthed
a rectal examination after birth
The guideline states informed consent for any of these aspects, but anecdotal evidence shows few people are told or asked about any of these procedures.
So what does the evidence say?
A review of the OASI bundle showed a small reduction in serious tears. However, the use of warm compresses (which does reduce risk) we’re used sporadically and not recorded, so it’s not clear if this may be a contributing factor. A study published last year looking at the hands on vs hands off approach showed that the hands on approach encouraged by the OASI guidelines increases the instances of third degree tears and episiotomy use. It didn’t reduce the risk of other degrees of tears.
Other older studies looking at the differences did not show a difference in the rates of tears when using hands on vs hands off.
If you are unsure if your hospital encourages use of the OASI bundle, ask your midwife. Ifyou are happy with the approach then you can consent at the time. However, if you do not want a hands on approach, episiotomy or rectal examination, state it in your birth preferences and inform your midwife. None of these procedures should be performed without first informing you of what they plan to do, and asking for your agreement beforehand.
You can read the full OASI guidelines here.
You can also read the research around hands on vs hands off approach to protecting the perineum here.