A perineal tear is a laceration of the skin and other soft tissue structures which, in women, separate the vagina from the anus.

Episiotomy, a very rapid birth, or large fetal size can lead to more severe tears which may require surgical intervention.

[3] Tears are classified into four categories:[4][5] In humans and some other primates, the head of the term fetus is so large in comparison to the size of the birth canal that delivery may result in some degree of trauma.

The risk of severe tear is greatly increased if the fetal head is oriented occiput posterior (face forward), if the mother has not given birth before or if the fetus is large.

[8] A surgical incision on the perineum skin called an episiotomy was historically used routinely in order to reduce perineal tears.

[12] Hands-on techniques employed by midwives, in which the foetal head is guided through the vagina at a controlled rate have been widely advocated, but their efficacy is unclear.

[21] A study by the Agency for Healthcare Research and Quality (AHRQ) found that in 2011, first- and second-degree perineal tear was the most common complicating condition for vaginal deliveries in the U.S. among women covered by either private insurance or Medicaid.

[26] There are claims that sometimes the perineum is excessively repaired after childbirth using a so-called "husband stitch" and that this can increase vaginal tightness or result in pain during intercourse.