Tears during childbirth, degrees 1-4


Firstly, both the vagina and vulva undergo several changes during pregnancy. The labia may swell due to increased blood flow as well as due to the weight and downward pressure of the growing belly. In some people, this can cause vulvar varicocities.

Here’s a post on how the pelvic floor is affected by pregnancy. (Swedish post) 

During a vaginal birth the cervix, birth canal and vulva opens in order for the baby to pass through it. During the baby’s descent, all surrounding tissues are stretched. The pelvic floor muscles are stretched 250-360 percent. Immediately after birth the labias will be distended and the pelvic floor and vaginal walls will be like an unstable hammock.


This post offers information on the type of birth related injury called perineal tears, which are graded from first-degree tears to fourth-degree tears. These tears are located between the vaginal opening and the anus, and involve the muscles which make up the superficial muscle layer of the pelvic floor.

An illustration of the pelvic floor anatomy. The deeper muscle layer is depicted to the left, the superficial muscles to the right. 


Most who have a vaginal birth will sustain some degree of perineal tearing, also known as perineal laceration. In most cases, a tear will need to be sutured in order to heal well. First-degree tears are small and only involve laceration of the skin and/or mucosa. These tears do not involve any muscle tissue and may not need sutures. The vaginal opening is distended and everything feels a bit wobbly or shaky, but the muscles are intact. Given time, the body will heal and recover. Anatomically however, some things will remain permanently altered following a vaginal birth. The supporting structures in the vaginal walls will need at least 6 months to recover and the pelvic floor, though intact, will need about 12 months. 


Second-degree tears involve the perineum, the area between the vaginal opening and anus. These tears involve the perineal muscles, as well as skin and vaginal mucosal. These tears always need suturing in order to heal properly. If injured pelvic floor musles are left unsutured, they will not recover fully and the support of the pelvic floor will be weakened. Restoring the anatomy while suturing is sometimes difficult which is why the vaginal opening can become longer or wider than prebirth. This may result in the perineum becoming shorter in women who have given birth vaginally. If the perineum is too short, this is an indication of the pelvic floor muscles not having been sutured well enough. You can read more on this topic here (Swedish post).


The anus is encircled by two sphincter muscles, the internal anal sphincter and the external anal sphincter. These muscles control the opening and closing of the anus. A tear involving one or both of these sphincters is also known as an obstetric anal sphincter injury (OASI).

A third-degree tear involves injury to all of the perineal muscles as well as the external and/or internal anal sphincter. If the anal sphincter tear is not sutured properly, this will result in fecal incontinence (also known as anal incontinence) which is the inability to stop your bowels from emptying at an inconvenient time. It can be very hard to differentiate between a second-degree tear and a third-degree tear. In order to do so, the midwife or doctor needs to examine the tear by so-called bidigital palpation.

Bidigital palpation means palpating with one finger in the rectum and one finger in the vagina at the same time, in order to be able to determine how much muscle mass is intact between the two fingers. If the muscle mass is thin this may indicate an anal sphincter injury, in which case the tear should be sutured by a doctor in an operating theatre. 

A fourth-degree tear involves the rectal mucosa as well as the external and internal anal sphincter. This means that before the tear is sutured, there’s nothing separating the rectum from the vagina. In such a case the rectal wall and both sphincters need to be sutured, as well as all the rectovaginal fascia, vaginal wall and perineal muscles. (This is the type of injury I got when our first child was born.)


The recovery process starts immediately following the birth. If you were sutured, the healing starts as soon as the final stitch is in place. The appearance of the vulva and vagina may be somewhat altered permanently. The end result of the recovery process depends on several factors, such as the size of the baby, how the birth went and in what way the tearing was sutured. Genetics also play a part in how the healing process goes and in how much scar tissue will be left once the tear has healed. 

Whether or not you will experience a persistent change of function in your pelvic floor depends largely on how well your tear was sutured. As with all muscle injury, the end result is also affected by how well the injured muscle is rehabilitated, which in the case of pelvic floor muscle injury is made up largely by pelvic floor exercise. 

This post was first published in 2015 as a part of a four part series. You can read the other parts here: (Swedish posts) 



This website is mainly in swedish. If you want to read more about pelvic floor issues and pelvic organ prolapse, you can use Google translate to read the swedish posts.

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