Max Brinsmead PhD FRANZCOGMarch 2013

Definitions

Some anatomy

Repair of 2nd degree obstetric injury Risk factors for 3rd & 4th degree

tears

The identification of 30 & 40 tears

Management of 30 & 40 tears

Avoiding obstetric injury

Pregnancy after previous 30 & 40 tears

Cochrane database Pubmed RCOG Guidelines (March 2007) NICE Guidelines for Intrapartum

Care (September 2007) Google Personal experience

1st degree perineal injury• Involves skin only

2nd degree injury• Involves perineal muscles (or perineal body)

but not the anal sphincter 3rd degree tear

• Involves the anal sphincter complex but not the mucosa of the anal canal or rectum

• 3a = Less than 50% of the external AS• 3b = More than 50% of the external AS but

the internal anal sphincter is intact• 3c = Both external & internal AS torn

4th degree tear• Both external & internal AS is torn and the

epithelium of the anal canal or rectum is breached

2nd degree trauma occurs in 16 – 90% of deliveries

Depends largely on whether restricted or liberal use of episiotomy is practised

Overall incidence of 3rd & 4th degree tears is 1:100 deliveries (1%)

But studies with endoanal ultrasound indicate that damage to the EAC occurs in up to 40% of vaginal births

RISK FACTOR ODDS RATIO

Nulliparity (primigravidity) 3–4

    Short perineal body 8

Instrumental delivery, overall 3

    Forceps-assisted delivery 3–7

    Vacuum-assisted delivery 3

    Forceps vs vacuum 2.88*

    Forceps with midline episiotomy 25

Prolonged second stage of labor (>1 hour)

1.5–4

Epidural analgesia 1.5–3

Intrapartum infant factors:

    Birthweight over 4 kg 2

    Persistent occipitoposterior position

2–3

Episiotomy, mediolateral 1.4

Episiotomy, midline 3–5

Previous anal sphincter tear 4

All variables are statistically significant at P<.05.

Requires systematic exam by a competent & experienced person

Extent of injury to be determined before repair commences

Analgesia• May require GA or regional block

Good light and exposure Must do a PR if sphincter damage

or 4th degree trauma is suspect• Use a second glove and discard

When the extent of injury is uncertain it is best to presume the worst

Use inert rapidly dissolving absorbable suture material

Use continuous suturing for all layers not interrupted

Less pain Bury the knots and warn the women

about how long the suture may be present

To theatre for GA or regional block if 30 or 40 tear is diagnosed or suspected• Some 3a trauma is suitable for repair under LA by

infiltration Use 2/0 or 3/0 Vicryl or PDS for sphincter

repair Retrieve and repair retracted sphincter

end to end or by overlap separate suture• One study had better results from overlap

repair Use NSAID as a rectal suppository

End to end repair

Overlap repair

Antibiotics after 30 or 40 tear • One RCT in support • Use broad spectrum plus Metronidazole

Laxatives for 7 – 10 days• Use stool softener and bulking agent

Offer physio with pelvic floor exercises Review by obstetrician after 6 – 8w Assess symptoms systematically Refer for endoanal ultrasound and

rectal manometry if there are symptoms of incontinence

The relevance of ultrasound abnormalities in asymptomatic women is uncertain

1. Passage of any flatus when socially undesirable

2. Any incontinence of liquid stool

3. Any need to wear a pad because of anal symptoms

4. Any incontinence of solid stool

5. Any fecal urgency (inability to defer defecation for more than 5 minutes)

SCALE

0 Never

1 Rarely (<1/month)

2 Sometimes (1/week–1/month

3 Usually (1/day–1/week)

4 Always (>1/day)

A score of 0 implies complete continence and 20 complete incontinence.

A score of 6 suggested as a cut-off to determine need for evaluation.

An evidence-based approach

Seven RCT’s with 5001 women and 8 cohort studies with 6463 women. Meta analysis confirms that restricted episiotomy will result in:

Less posterior trauma (RR 0.87, CI 0.83 - 0.91) More anterior trauma (RR 1.75, CI 1.52 - 2.01) Fewer 30 and 40 tears (RR 0.74, CI 0.42 - 1.28)

Some studies also point to: Overall more intact perineums Less perineal pain Quicker return to coitus with restricted use of

episiotomy and More anal sphincter damage with liberal

episiotomy But no difference in…

Sexual function at 3m & 3 yrs or bladder function

Routine episiotomy is not recommended for spontaneous birth

Episiotomy should be performed when clinically indicated • e.g. fetal compromise suspected or

instruments required

Mediolateral episiotomy is best • i.e. start at the posterior fouchette and

proceed at an angle of 45 - 60 degrees

Tested anaesthesia is required• Except in an extreme emergency

A case control study showed that episiotomies that:• Begin close to the posterior fourchette• Are <15 and >60 degrees from the axis• Are too short• Or not deep enough

Are associated with an increased risk of anal sphincter injury

One large RCT in Australia (1340 women in 3 sites) of midwife massage between contractions in the second stage:

No effect on any measure of obstetric trauma, pain, return to coitus or urinary and bowel function

There was no apparent measure of compliance

But the study is confirmed by a US RCT of 1211 women in which compliance was high

The Epi-No device (a self-performed progressive dilation of the perineum from 36 weeks) significantly increases the rate of intact perineum in nullipara and appears safe

2001 – a prospective trial of 50 nullipara (published in German)• Significant reduction in the rate of episiotomy (49%

vs 82%)• Fewer “perineal tears” (2% vs 4%)• Shorter 2nd stage (mean 29 vs 54 minutes)

2004 – a prospective trial of 31 nullipara in Singapore• Used the device for a mean of 2.1 weeks• Fewer episiotomies (50% vs 93%)• Overall trauma rate 90% vs 97% but the trauma

appeared “less severe”• The device was “safe”

2004 – Pilot study from Melbourne Aust. of 48 nullipara• Significantly more intact perineums (46% vs 17%)• Reduced rate of episiotomy (26% vs 34%)• Shorter second stage (mean 61 vs 81 minutes)• No effect on instrumental delivery rate or Apgars

2009 – A RCT of 276 German nullipara (published in AustNZ J O&G)

• Significantly more intact perineums (37.4% vs 25.7%)

• A trend towards fewer episiotomies

• No effect on the rate of “tears”, duration of 2nd stage or pain

• No increased risk of infection

One large US observational study (2595 women) found that:

Warm compresses reduced the need for episiotomy in nulliparas and was borderline for multiparas

Also reduced the rate of spontaneous 20

tears in both

But this was not confirmed by another US RCT of 1211 women

One large UK RCT of 5316 ♀ found: A small reduction in perineal pain at 10 days

from “hands on” No difference in any measure of obstetric

trauma Inexplicably fewer manual removals in the

“hands poised” group (2.6% vs 1.5%) Broadly similar findings in an

Austrian study of 1076 women But episiotomy was more common in the

“hands on” group NICE concludes that either

technique is appropriate And noted evidence that there is less trauma

when the head delivers between contractions

One RCT of 185 women found that:

No effect on perineal pain But less dyspareunia when coitus was

resumed And fewer second degree tears in the

treated group (RR 0.63, CI 0.42 – 0.93)

But NICE concludes that Lignocaine spray should not be used

There are no prospective trials and only a few retrospective studies

The risk of repeat 30 and 40 trauma is similar to the original incidence

There is some evidence that if the woman is asymptomatic then vaginal birth does not further increase the risk of those symptoms

There is some evidence that for symptomatic women then vaginal birth does increase the severity of those symptoms

Routine episiotomy is not recommended

Discussion about intrapartum care should cover…

Current symptoms of dysfunction of the anal sphincter The previous trauma The risk of recurrence Success of previous repair Psychological aspects of the trauma

Then a combined decision concerning subsequent mode of birth and intrapartum care can be made