Natural tears are particularly common in women having their first child. Most tears occur because the vagina hasn’t stretched enough to relieve the pressure of the baby’s head.
How common are natural tears?
Of course, everyone is different and there are many factors that make moms more prone to tearing than others. For example, tearing is more common in smaller women with naturally shorter perineums. Learn more about other predisposing factors below in the section, “Who is more at risk?”
The 4 degrees of tearing
There are 4 different types of vaginal tears from childbirth: (1)
1st-degree: tearing of the perineal skin and mucous membrane
Healing times and pain often increase with higher degrees of tearing. The deeper the tear, the more muscle is damaged, and torn muscles take particularly long to heal. The most severe case, tears that reach the anus, also has a lengthy recovery and is often the most tedious and painful.
Strong evidence suggests that episiotomies increase a mother’s chance of tearing further along the incision. Once the vulva is cut, its resilience is compromised and the perineum is more likely to tear, especially under the pressure of a crowning head. Furthermore, episiotomies are often paired with forceps or vacuums to help get the baby out.
Tools alone create additional pressure on the vulva and have been linked with perineal tearing. Assisted births are stressful and the mother is likely tense and scared. Pressure from the baby combined with added pressure from instruments can heighten a mother’s chance of tearing. (2)
First-time moms tend to tear more often than moms who’ve given birth in the past. This is likely because the skin and muscles of the perineum are stretching to a large extent for the first time and the body is undergoing dramatic and unprecedented physical changes to deliver the baby. During a second or third birth, the vulva has stretched to that extent before, so the skin and muscles stretch more readily. (2)
A particularly large baby causes more pressure on the perineum during birth. Large babies have also been associated with higher degrees of tearing (2nd-, 3rd-, and 4th-degree tears). This is because the skin and muscles of the perineum can’t stretch enough to make way for the baby, so strong pressure builds which could lead to a tear. (2)
Mothers who have a small physique might be more at risk of tearing because their perineum is shorter. There is less room for the vagina and outer skin to stretch during delivery. It has been seen that 1 in 5 teenage mothers experience a perineal tear from childbirth. This points to some additional risk of tearing for mothers who have a smaller physique and thus a shorter perineum. (3)
But it’s not just small women—heavier women may also be more at risk of tearing. Perineal tears have been associated with mothers who are overweight. Skin elasticity and muscle health may be impaired by a particularly high body mass index, which could affect a mother who is birthing a large baby or giving birth for the first time. (3)
Recurring low blood pressure may limit a mom’s muscles during birth. Gestational diabetes is a form of diabetes that occurs in women during pregnancy. Gestational diabetes often causes high blood pressure in both the mom and baby. If not monitored carefully, the high blood pressure can lead to the baby being overfed (through the umbilical cord) and cause the baby to grow extra large, leaving the mom more at risk of tearing at birth. (4)
Conclusion