Episiotomy helpful in forceps births says Canadian study

An episiotomy is a minor surgical procedure that’s supposed to make vaginal births easier. Doctors largely stopped doing them as evidence mounted they did more harm than good. A study published Monday in the Canadian Medical Association Journal suggests it’s time for a revisit.

The study, by Giulia Muraca, a postdoctoral fellow at the Karolinska Institute in Stockholm, concluded that in some cases, episiotomies benefit women in labour.

The study looked at the use of episiotomy in more than 2.5 million births in Canada between 2004 and 2017. As predicted, in low-risk vaginal deliveries in which instruments were not needed, episiotomy was associated with a higher risk of injuries to the mother.

However, in births that required forceps and vacuum suction to help birth the baby, when an episiotomy was performed, the risk of anal sphincter injury to the mother decreased by up to 42 per cent.

The authors concluded that health professionals reconsider doing an episiotomy in births in which forceps or vacuum suction are needed.

That the study’s conclusion runs against current conventional wisdom is an understatement.

Routine episiotomy re-thought

For many decades, obstetricians routinely did episiotomies on women in labour. The change in thinking began with Dr. Michael Klein, a family medicine professor and one of Canada’s leading experts in maternity care. Klein’s work alongside midwives convinced him that episiotomies did more harm than good.

He and colleagues conducted a randomized trial published in 1994 showing that episiotomy caused the very trauma to the vagina that the procedure was supposed to prevent.

That study and others resulted in rates of episiotomy plummeting from 65 to as low as 12 per cent, and cases of severe trauma to mothers during childbirth dropped from 4.5 to just one per cent. Few studies have had that dramatic an impact on medical practice.

The authors of the current study believe that the landmark 1994 study had such a powerful impact it influenced doctors to abandon the procedure across the board. They believe that doctors may have arrived at an incorrect conclusion that episiotomy is always harmful even though there was evidence back then that procedure reduced complications in women who needed instruments like forceps and vacuum suction.

In effect, doctors threw the baby out with the bathwater.

Like its 1994 predecessor, the current study provides more clarity on the benefits of episiotomy. We also need more clarity on the risks.

Pelvic floor health

Episiotomy can cause or contribute to dysfunction and even damage to the woman’s pelvic floor, as discussed recently on, White Coat, Black Art. The pelvic floor is the sleeve of muscles and ligaments at the surrounding the birth canal that helps support it as well as the bladder and the rectum. As many as one in four women with pelvic floor dysfunction have urine incontinence for months and even years following vaginal birth. In some women, the procedure causes sexual problems and even fecal incontinence. For years, they were under recognized, but that is changing.

The study in CMAJ does not mean a return to routine episiotomy. The Society of Obstetricians and Gynaecologists of Canada (SOGC) has recommended against doing the procedure routinely for operative vaginal births, meaning the ones in which forceps and other interventions are used. As recently as this year, the SOGC reaffirmed that recommendation. That’s despite accumulating evidence that episiotomy reduces tears to the anal sphincter during operative vaginal births.

The study’s authors say episiotomy should be considered in births in which instruments are used, especially forceps. Women should ask their health-care provider about the risks and benefits of the procedure. And they should stay abreast of the latest scientific evidence.