57442286Severe perineal trauma: Third and Fourth degree tears


Sustaining perineal trauma during childbirth is very common, particularly where it is your first vaginal birth. The perineum is the area of skin between the vagina (birth canal) and anus (back passage). During a vaginal birth this area stretches to accommodate the passage of the baby and can often tear to varying degrees. If you have an assisted birth with forceps and/or your baby develops fetal distress, you may need an episiotomy. This is a cut in the perineum to make the opening larger and aid your baby’s birth. An episiotomy is only performed where there is a clinical need to expedite your baby’s delivery. NB. It is possible to sustain a perineal tear even where you have had an episiotomy.

A much smaller number of women who have a vaginal birth will however, end up sustaining more severe perineal tears. These are called Third and Fourth degree tears.


What is a Third degree tear?

This type of tear involves the vaginal tissue, perineal muscles, skin of the perineum and also the anal sphincter (the ring of muscle surrounding your back passage). Tearing of the anal sphincter can be either partial or compete.


What is a Fourth degree tear?

This is the most serious type of tear; the anal sphincter is torn and the back passage is consequently opened.


What causes Third and Fourth degree tears?

These tears can happen to any woman having a vaginal birth. There are however, specific circumstances where the risk of sustaining a Third or Fourth degree tear is increased:

  • The baby is of above average birth weight (ie large baby)
  • There is difficulty delivering the baby’s shoulders (called shoulder dystocia)
  • The baby’s birth is assisted (with difficulty) using forceps or the ventouse
  • The baby is born face up with their back lying against their mother’s back (also called a ‘face to pubes’ or ‘occipito-posterior’ delivery)
  • The distance between the vagina and anus is shorter than normal
  • The tissue of the perineum happens to be more ‘fragile’ than is usual.


Immediate management of Third and Fourth degree tears

Immediately after you have given birth, the midwife or doctor who helped you deliver your baby will examine your vagina, perineum and back passage. This examination assesses the extent of any trauma sustained during the birth. Where a Third or Fourth degree tear is diagnosed, this will need to be repaired by an experienced doctor in the operating theatre, where there is much better lighting.

If you had an epidural in labour, this will be topped-up with local anaesthetic to make sure you are completely numb. If you didn’t have an epidural, you will have an intravenous infusion (drip) sited and the anaesthetist will give you a spinal anaesthetic. This works in the same way as an epidural but takes effect a lot more rapidly. A urinary catheter will also be inserted to ensure the bladder doesn’t overfill leading to urinary retention. See also our article on ‘Caring for your bladder after childbirth’. The maternity staff will ensure your numbed legs and feet are well supported in lithotomy poles; these ensure the doctor has a good view of the tear. The doctor will then carefully suture (stitch) the Third/Fourth degree tear layer-by-layer, using sutures that are dissolvable and do not need to be removed.

Once the doctor has completed their repair, they will examine your perineum again, including your back passage and will often insert a strong ‘painkiller’ suppository (eg Diclofenac/Voltarol) at the same time. You will also be given an antibiotic to prevent any infection from developing – this can be given as a suppository (in your back passage) or as an intravenous injection through the cannula (plastic needle) of your drip.


Postnatal after care

The urinary catheter will remain in place for between 12 and 24 hours post birth. This ensures you don’t develop urinary retention while you are still numb from the epidural/spinal anaesthetic and also allows any oedema (swelling) from the birth to subside. The doctor will also prescribe regular pain relief to keep you comfortable and a syrup-like medicine, called Lactulose, which helps to keep your stools (‘poo’) soft. This makes it more comfortable to have your bowels open, so you will need to keep taking the Lactulose for a few weeks. The doctor may also prescribe a course of antibiotic tablets for the initial few days post birth to stop any infection developing. You may also be prescribed sachets of a mixture which is a ‘bulking’ agent called Fybogel. The maternity staff will also encourage you to drink plenty of fluids – this helps to keep your stools soft and prevent constipation, and is also very important while you have the urinary catheter in place.

Hygiene is very important in promoting healing, so keeping your perineum clean and dry, and changing your maternity pads at least four hourly are important. A healthy balanced diet, including plenty of foods that are rich in protein will also help to promote healing. See also our articles on ‘Healing ways’ and ‘Eating well for you and your baby’.


Opening your bowels post birth

When you have had a Third or Fourth degree tear, having your bowels opened is likely to feel very uncomfortable for the first few days. Taking regular pain relief as prescribed by the doctor will help to ease this. There is a very rich blood supply in this part of your body, so healing actually takes place very quickly. Although, it may be the last thing on your mind, doing your pelvic floor exercises is extremely important. When you tighten your pelvic floor muscles, this pushes all the ‘old’ blood out of the area and when you release them, ‘fresh’ blood enters, promoting healing. Pelvic floor exercises are also very important for restoring muscle tone after labour and birth. See also our article on ‘Postnatal Exercises’. A physiotherapist will see you while you are staying on the postnatal ward and they can give you additional information and guidance.

NB. You should not perform pelvic floor exercises while you have a urinary catheter in place.

As your Third/Fourth degree tear heals, the discomfort you feel when having your bowels opened will gradually subside. However, because these are more severe perineal tears, discomfort can often last for a good month; sometimes even a little longer. It’s very important that you don’t resist the urge to have your bowels opened, because this could result in constipation and make things worse. The doctors will prescribe regular pain killers and Lactulose for you to take home with you when you are discharged from hospital.


Are there any complications associated with these types of tear?

Yes, there can be – women who have Third or Fourth degree tears can struggle to control their flatus (‘wind’) and/or their bowel motions (called faecal incontinence). These problems are very common immediately following the birth, but can also occur quite sometime afterwards. Because Third and Fourth degree tears involve the back passage, there is also an increased risk of developing infection. If you start to have increased pain/discomfort in the area, notice swelling and/or inflammation (redness that feels hot when touched), or you develop a high temperature or start to feel unwell (flu-like), contact your midwife or GP. These symptoms can indicate that you have developed an infection and your GP may decide to prescribe antibiotics. See also our article on ‘Safeguarding against postnatal sepsis (infection)’.

Should you have any concerns or are experiencing difficulties with bowel/flatus and/or bladder control, it is very important that you inform your midwife, health visitor or GP. They will be highly sensitive to your feelings and can ensure that you receive the advice, support and any treatment that you might need.


Follow up

You will be seen six weeks’ post birth to check that your Third/Fourth degree tear has healed and to review any problems that you might be experiencing. If any additional treatment or follow-up is required, this can be discussed and any referrals for further care/treatment made.

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