Perineal Tearing in Labor - Part 1: What is a perineal tear?
The thought of perineal tearing causes shivers to run down most mama’s backs. The perineum is the area between the vaginal opening and the anus that sometimes tears during labor. In fact, 53-79% of women who have a vaginal delivery will have some type of tearing or laceration to the perineum. Depending on where you look, some studies say that as little as 10% of first-time moms will have zero tearing while 31% of second-time mamas will deliver vaginally without tears. (1) Tearing during birth can occur to the perineum, anus (where you have a bowel movement), urethra (where you pee) or other parts of the vulva, including the labia.
Perineal Tearing Classification
I think it’s important to understand the different types of tears to better understand what is affected in perineal tears. During normal pregnancy, the pelvic floor muscles can stretch over THREE TIMES their normal length to allow the baby to drop into the pelvis and descend. The collagen matrix which helps support the muscles and tissue also increases by 140%. These natural increases are the body’s way to prepare the pelvic floor for childbirth. Unfortunately, there are times when these changes occur too fast or too slow or the tissue is stretched beyond what it can support and this is when tearing happens.
First-degree tears
First degree tears affect only the skin and no muscles were involved. In general, first degree tears do not require stitches and will heal on their own. In some instances, a small number of stitches may be beneficial.
Second-degree tears
Second degree tears affect both the skin and the muscle of the perineum and generally requires stitches. It often takes ~6-8 weeks for a mother to feel “normal” and/or comfortable again.
Episiotomy
An episiotomy is a cut made by the provider into the perineum and vaginal wall to make a larger vaginal opening. This is often done to help your baby be born and involves the same muscles and tissue as a 2nd degree tear. However, some episiotomies can extend further than the initial cut and become a 3rd or 4th degree tear.
Third-degree and fourth-degree tears
3% of first-time moms will have 3rd and 4th degree tears where the tears affects not only the muscle but extends deep into the muscles that control the anus. In moms who have had more than one vaginal delivery, this rate decreases to .8%. (2) These tears are more extensive and often times require stitches and may even require surgical repair. A 4th degree tear actually goes through the anal mucosa (lining of the anus) and the anal sphincter, the muscle that loops around the anal canal and helps to control the release of gas or bowel movements.
Stay tune for Part 2: What we know about why the perineum tears and how to modify risks