9.11 Perineal Tears

Question 1

What factors make perineal tears more likely?

Answer 1

First births (nulliparity)

Large babies (over 4kg)

Shoulder dystocia

Asian ethnicity

Occipito-posterior position

Instrumental deliveries

Question 2

What has happened in in degree of perineal tear?

Answer 2

First degree
– injury limited to the frenulum of the labia minora (where they meet posteriorly) and superficial skin

Second degree
– including the perineal muscles, but not affecting the anal sphincter

Third degree
– including the anal sphincter, but not affecting the rectal mucosa

Fourth degree
– including the rectal mucosa

Question 3

What are the subcategories of 3rd degree tears?

Answer 3

3A – less than 50% of the external anal sphincter affected

3B – more than 50% of the external anal sphincter affected

3C – external and internal anal sphincter affected

Question 4

What lasting complications can there be from perineal tears?

Answer 4

• Urinary incontinence
• Anal incontinence and altered bowel habit (3rd and 4th degree tears)
• Fistula between the vagina and bowel (rare)
• Sexual dysfunction and dyspareunia
• Mental health

Question 5

What is done before forceps delivery?

Answer 5

Episiotomy - allow space for forceps

45 degree angle ie mediolateral episiotomy

Question 6

What can be done to reduce the risk of perineal tears?

Answer 6

Perineal massage from 34 weeks onwards

- stretch and prepare tissue for delivery