No science behind use of episiotomies

By Jenny Manzer

PHILADELPHIA – Some physicians are deciding who gets an episiotomy in an arbitrary, unscientific way, two studies from Thomas Jefferson Medical College suggest.
   In the first study, the team analysed data from 18 hospitals. They found episiotomy rates varied substantially. In some, the rate was as low as 20% and in others as high as 73%.
   Much of the variation appeared unrelated to patient characteristics such as maternal age, researchers found.
   Findings also showed women who gave birth in hospitals with high episiotomy rates were far more likely to suffer severe perineal trauma.
   Rates of third- or fourth-degree vaginal tears varied by hospital, from a low of 4% to a high of more than 13%.
   "When you look at variables that you can actually measure, episiotomy per se is the most important or significant factor associated with a severe tear," said study co-investigator Dr. Jorge Tolosa, an assistant professor of obstetrics and gynecology at Jefferson.
   The study sample included more than 14,000 low-risk nulliparous women giving birth in the years 1994 to 1997. Data from electronic birth records and hospital discharge summaries were used to calculate the odds of having an episiotomy and of having a third- or fourth-degree vaginal tear.
   Researchers controlled for maternal age, race/ethnicity, education and infant birthweight.
   The subjects' babies were of normal weight, delivered without vacuum or forceps, and had no indication of malpresentation.
   Overall, almost 42% of the study group had an episiotomy. About 10% of women in the episiotomy group had a severe tear, compared to 6% among those who did not have the procedure.
   The findings add to a growing body of evidence indicating the lack of benefit and potential harm associated with routine use of episiotomy, the researchers concluded in a presentation to the recent Society of Maternal Fetal Medicine meeting.
   In their second study, the Jefferson researchers sought to determine if the mounting evidence supporting selective use of episiotomy has actually influenced practice patterns.
   They reviewed more than 34,000 deliveries at Thomas Jefferson University Hospital from the years 1983 to 2000. They found the overall episiotomy rate decreased to 19% in 2000, compared to almost 70% in 1983.
   "The good news is the rate of episiotomy is decreasing, and that is a good trend," said Dr. Tolosa, who also participated in the second study.
   "As to whether 19% is a reasonable number . . . the answer is probably no," said Dr. Tolosa, noting in some parts of California the rate is as low as 2% to 3%.
   Their results also showed episiotomy rates differed significantly by race. The rate for white women decreased to 32% in 2000, compared to 79% in 1983. The rate for black women fell to 11.2%, compared to 60.5%.
   White women were found to consistently undergo episiotomy more frequently than black women, even after researchers controlled for factors such as differences in parity, prenatal care or health insurance.
   "Physician perception of differing risks of severe spontaneous lacerations between racial groups may also factor into white women undergoing episiotomies more often in a misguided attempt to prevent this," the researchers wrote in Obstetrics & Gynecology.
   "It may also simply be a marker of the arbitrary and non-scientific nature employed by the physician in determining which patients need an episiotomy."
   Dr. Tolosa said he suspects the attitudes of individual physicians can have a strong trickle-down influence on episiotomy rates at their hospitals. "The reasons to do episiotomies have to be looked at further, and probably delineated better, so the rate will continue to decrease," he said, adding there are still some physicians who do episiotomies routinely.
   The most recent figures available for Canada showed an episiotomy rate of 37.7 per 100 vaginal births in 1993/94. The rate has dropped steadily over the years, from 66.8 per 100 births in 1981/82.