A study in the June 2008 issue of Obstetrics & Gynecology examines what happened when women who had an episiotomy during their first birth went on to have a second vaginal delivery. The researchers were interested in whether women who had an episiotomy were more or less likely to tear during subsequent deliveries.
Records were reviewed for 6,052 women who had their first and second deliveries at a Pittsburgh women’s hospital from 1995-2005 (excluding those who had another episiotomy at the second delivery).
The authors found significantly higher rates of an intact perineum or first degree laceration (71.4% combined) at second delivery in women with no prior episiotomy compared to those who had the procedure at first birth (44.2% of these women had no or first degree laceration). Rates of second, third, and fourth degree tears were significantly higher in those with prior episiotomy.
Although the researchers do not provide information on why episiotomies were chosen in the first deliveries, they make the following observation about demographic factors:
Women who had episiotomy at first delivery were older, more likely to be white, married, and have higher education and commercial insurance. These demographic characteristics were also all associated with having a private practice provider, and notably, 94.6% of women who had an episiotomy at first delivery were patients of private practitioners.”
Other risk factors, such as infant birth weight, are mentioned in the paper, although the primary focus is on whether past episiotomy increases risk of future tearing.
What surprised me, given fairly widespread discussion over the past two decades about reducing routine episiotomy, was that when the researchers compiled the records on first and second births over those recent years, 47.8% of them had an episiotomy at their first delivery. The American College of Obstetricians and Gynecologists released a practice bulletin in 2006 recommending restricted rather than routine use of the procedure (after the period of this study). However, literature questioning routine use began appearing in the early 1980s, so I was surprised that it remained so high at the women’s hospital where this research was conducted.