Just before birth, the baby’s head distends the perineum (the area between the vagina and the rectum) and stretches the skin around the vagina. As the baby’s head comes through the vagina’s opening, it may tear the tissues in the back, or posterior, part of the vaginal opening, sometimes even to the point that the tear extends into the rectum.
To minimize tearing of the surrounding skin and perineal muscles, your practitioner may make an episiotomy — a cut in the posterior part of the vaginal opening large enough to allow the baby’s head to come through with minimal tearing or to provide extra room for delivery.
Although an episiotomy may decrease the likelihood of a severe tear, it doesn’t guarantee that you won’t get one (that is, the cut made for the episiotomy may tear open even further as the baby’s head or shoulders are delivered).
Your practitioner doesn’t know whether you need an episiotomy until the head is almost out. Some doctors routinely make an episiotomy, and others wait to see whether it’s definitely necessary. Episiotomies are more common in women having their first baby than in those who have delivered before because the perineum stretches more easily after a previous birth.
Tell your practitioner if you have strong wishes regarding receiving an episiotomy. Keep in mind, though, that some natural tears can be worse than an episiotomy.
The type of episiotomy made depends on your body, on the position of the baby’s head, or on your practitioner’s judgment. Practitioners can choose from two main types of episiotomies:
Median: Straight down from the vagina toward the anus
Mediolateral: Angled away from the anus
A local anesthetic can numb the area if you haven’t had an epidural.
A median episiotomy may be less uncomfortable later on, and it may heal more easily. However, a median episiotomy has a slightly greater chance of extending to the rectum. A mediolateral episiotomy, on the other hand, may be more uncomfortable later on and take longer to heal, but it has less chance of extending to the rectum when the baby’s head passes through.
Most tears or lacerations that occur during delivery are in the perineum or are extensions of an episiotomy, which is also in that area. Occasionally, especially when the baby is exceptionally large or you have an operative vaginal delivery, lacerations can occur in other areas, such as the cervix, on the vagina’s walls, the labia, or the tissue around the urethra.
Your practitioner examines the birth canal carefully after delivery and sews up any lacerations that need to be repaired. These lacerations usually heal very quickly and almost never cause long-term problems. Don’t worry about having the stitches removed — most doctors use the type of sutures that dissolve on their own.