Does an Epidural Increase Your Risk for a Severe Tear?

By: Crystal Wallentine My childbirth instructor says it's not pain I'll feel during labor, but pressure. Is she right? Perhaps…in the same way that a tornado might be called an “air current.”

Utah has the highest epidural rate in the nation – over 90% according to The United States has the highest epidural rate in the world. Those countries with socialized healthcare have epidural rates that are significantly lower. For example 25% of women in the UK use epidurals for childbirth. (Unless you go to a private hospital, where the rates are double the public hospitals in socialized healthcare nations.)

This study examined the risk of third and fourth degree tearing as a result of childbirth. First-degree vaginal tears are the least severe, involving only the skin around the vaginal opening. Second-degree vaginal tears involve vaginal tissue (vaginal mucosa) and the perineal muscles — the muscles between the vagina and anus that help support the uterus, bladder and rectum. Third-degree vaginal tears involve the vaginal tissues, perineal muscles and the muscle that surrounds the anus (anal sphincter). Fourth-degree vaginal tears are the most severe. They involve the perineal muscles and anal sphincter as well as the tissue lining the rectum.

Traditionally, physicians and pregnant women thought that getting an epidural may increase your risk for a severe tear. A study of over 18,000 women in England has shown otherwise. As it turns out, epidurals do not increase your risk for severe tearing during childbirth!

In this study, for all vaginal deliveries, doctors compared the incidence of third- and fourth-degree tears between pregnant women who received an epidural and those who did not. This was done by chart review after the women had decided to have an epidural or not, to prevent research bias.

Among women who had spontaneous vaginal deliveries (they were not induced but went into labor on their own), the risk for third- and fourth- degree tears was 1.9% if they had an epidural, and 2.7% if they did not have an epidural. I know that 1.9% does not seem like much. What it means is almost 2 out of 100 women have a decreased risk of tearing. I don’t know about you, but if there were a risk that 2 in 100 people would die in a plane crash every time you flew, I wouldn’t get on that plane.

The risk for perineal tear was also lower for women who received an epidural who also had a delivery assisted by forceps or vacuum extraction. An assisted birth (sometimes called an instrumental or operative vaginal birth) uses instruments (either forceps or vacuum device) that are attached to your baby's head so that he/she can be pulled out. This study did not include patients that had episiotomies during birth.

Dr. MacDougall, the lead investigator of the study, said that he believes “that in some women, perineal injury results from rapid, uncontrolled delivery of the fetal head. Rapid descent of the head produces severe pain, which causes an overwhelming urge to push just when the tissues are most vulnerable to injury. This can result in a severe tear.”

The study did not compare delivery techniques, or minor tears (first- or second-degree tears).

In conclusion, epidurals do not increase your risk for severe tearing during childbirth. I hope this information is helpful when deciding whether to have an epidural during your birthing experience.

Source: 2011 Annual Meeting of the Society for Obstetric Anesthesia and Perinatology (abstract 13).