Perineal Tears

Question 1

What is a perineal tear and why does it occur?

Answer 1

• occurs when the external vaginal opening is too narrow to accommodate the baby
• this leads to skin / tissues in the area tearing as the head passes

Question 2

What factors increase the likelihood of a perineal tear occurring?

Answer 2

• large babies ( > 4kg)
• Asian ethnicity
• occipitoposterior position
• shoulder dystocia
• first birth (nulliparity)
• instrumental delivery

Question 3

How can perineal tears be classified?

Answer 3

first degree:

• limited to the frenulum of the labia minora + superficial skin

second degree:

• involves the perineal muscles (but not the anal sphincter)

third degree:

• involves the anal sphincter (but not the rectal mucosa)

fourth degree:

• involves the rectal mucosa

Question 4

How can a third degree tear be further subdivided?

Answer 4

3A:

• involves < 50% of the external anal sphincter

3B:

• involves > 50% of the external anal sphincter

3C:

• involves the external + internal anal sphincters

Question 5

How does the management differ for the varying degrees of perineal tears?

Answer 5

• sutures are NOT usually required for first degree tears
• anything above this usually requires sutures
• third and fourth degree are usually repaired in theatre

Question 6

What additional measures are taken to reduce the risk of complications?

Answer 6

• broad spectrum abx to reduce risk of infection
• laxatives as constipation can result in wound dehiscence
• physiotherapy to reduce risk / severity of incontinence
• followup to monitor longterm complications

wound dehiscence = reopening of a wound following surgery

Question 7

When may women be offered C-section in the future?

Answer 7

women who are symptomatic after a third or fourth degree tear are offered elective C-section in future pregnancies

Question 8

What are the short term complications associated with a perineal tear?

Answer 8

• bleeding
• pain
• infection
• wound dehiscence / breakdown

Question 9

What are the long-term complications associated with a perineal tear?

Answer 9

• urinary incontinence
• anal incontinence / altered bowel habit (in 3rd/4th degree)
• dyspareunia + sexual dysfunction
• fistula between the vagina and bowel (rare)

Question 10

What procedure may be performed during delivery to prevent perineal tears?

Answer 10

episiotomy

• the perineum is cut prior to delivery of the baby
• this is done in anticipation of needing additional room for delivery (e.g. forceps)

Question 11

What is the most common location of episiotomy?

Answer 11

mediolateral episiotomy

• a cut is made around 45 degrees diagonally
• the cut passes from the vaginal opening downwards + laterally
• it avoids damaging the anal sphincter
• it is performed under LA and sutured after delivery

Question 12

What is a perineal massage and why is it performed?

Answer 12

• the skin around the vagina and anus (perineum) is massaged from 34 weeks onwards
• it stretches the tissues to reduce the risk of perineal tears