8 Perineal Management / VBAC Flashcards
Risk factors for perineal trauma
Parity
- nulliparity is a risk factor for perineal trauma due to the relative inelasticity of the perineum
- This includes women who are having a VBAC as their perineum has not undergone the stretching of vaginal birth
Fetal birth weight
- Macrosomia is a risk factor for perineal trauma
Mode of delivery
- Operative vaginal deliveries were associated with increased risk for perineal trauma
- This risk is increased with instrumental deliveries such as vacuum and forceps
- Forceps delivery is the highest risk as it places the most trauma and force on the perineum
Duration of the second stage of labour
- A prolonged second stage increases the risk of perineal trauma
Abnormal fetal positions and presentations
- The occipitoposterior position is associated with greatest perineal trauma due to the increased circumference the perineum has to stretch
Maternal age
- Women at an advanced maternal age may be at risk due to the changes in elasticity of perineal tissue throughout life
Perineal trauma risk reduction strategies
Manual perineal protection
- Hands on technique
- Slowing the delivery of the baby’s headache with one hand
- Protecting the perineum with the other hand
- Coaching the mother to not push when the baby’s head is crowning
- Choosing a maternal birth position allowing the accoucheur to visualise the perineum
Episiotomy
- Surgical cutting of the perineum to enlarge the vaginal opening for birth during the last part of the second stage of labour
- Prevents severe perineal tears, reduced urinary and faecal incontinence, easier to heal
- Median episiotomy - begins in posterior fourchette through midline to the central tendon of the perineum
- Mediolateral episiotomy - incision at the midline and lateral / downwards away from the rectum
- Lateral episiotomy - 1-2cm from the midline to the ischial tuberosity
Warm compression on perineum
- Reduces maternal pain and helps the perineum stretch
Perineal trauma risk reduction - role of the midwife
- Support the woman to have a normal vaginal birth
- Minimise potential for perineal trauma
- Deciding between hand on, hands off, hands poised
- Warm compress
- Encourage a slow and controlled birth - verbal guidance
Indications for episiotomy
- Premature delivery
- Breech presentation
- Fetal macrosomia
- Shoulder dystopia
- Operative delivery
- Abnormal fetal heart function
- Tear-prone perineum
First & Second degree tear
First degree - injury to skin only, injury to the perineum involving perineal muscles but not the anal sphincter
Second degree - injury to the perineum involving the anal sphincter complex
Third degree tears
- Third degree (3A) - less than 50% of external sphincter thickness torn
- Third degree (3B) - more than 50% of external sphincter torn
- Third degree (3C) - internal anal sphincter torn
Fourth degree tear
Fourth degree - injury to the perineum involving the anal sphincter complex and anal epithelium
Immediately following birth
- Assessment of the vagina, perineum, and anus immediately after birth to identify the extent of the trauma
- Ensure woman is in a comfortable position with adequate lighting and a clear view of the perineal area/genital structures
- Confirm with the woman that the local or regional analgesia is working
- Examine the rectal area to see for external or internal sphincter damage and potential perineal muscle damage
- As repairing and suturing is a surgical process, swabs and suturing material should be recorded before and after the procedure
Pelvic sling
comprised of the levator ani muscles, and are injured in a second degree tear. These 4 muscles are known as the pelvic sling as they support the urethra and neck of the bladder to prevent urinary leaks
Buttonhole tear
anal sphincter is intact however the rectum is damaged
VBAC
- 50% of women who go for VBAC will successfully have a vaginal birth
- Women with an uncomplicated previous c-section should be given the opportunity to discuss VBAC
- Risks and benefits should be discussed
- Women can make the decision
- Complications can include high risk, scar rupture, urgent c-section, uterine rupture
