Thirty RCTs and 15 prospective cohort studies were included. There were 7 RCTs (n=4,991) for KQ1; 1 RCT (n=407) for KQ2; 17 RCTs (n=9,757) for KQ3; 3 RCTs (n=2,377) and 12 cohort studies (n=5,260) for KQ4; and 2 RCTs (n=1,703) and 7 cohort studies (n=4,657) for KQ5.
Routine versus restricted use of episiotomy (KQ1).
The use of episiotomy ranged from 7.6 to 53% in the restricted use groups and from 44.9 to 83% in the routine use groups. Overall, women in the restricted use groups had less severe posterior perineal trauma, more frequent but not more severe anterior vaginal trauma, less need for suturing, and a higher probability of having an intact perineum compared with those in the routine use groups. Women in the restricted use group also had less short-term pain and were more likely to resume intercourse earlier than those in the routine use group.
Episiotomy type (KQ2).
One poor-quality RCT found that women who had a midline episiotomy had a significantly higher rate of anal sphincter injuries compared with those who had a mediolateral episiotomy.
Method of repair and materials used (KQ3).
Heterogeneity was high for both methods and materials. Evidence from 8 studies indicated that polyglycolic acid sutures were associated with less perineal pain, less requirement for analgesia, and better short-term healing compared with chromic catgut sutures.
Incontinence and pelvic floor defects (KQ4).
All but 2 studies reported results for mediolateral rather than midline episiotomy. Only 5 studies reported follow-up data at 1 year or longer after childbirth. Overall, the studies did not identify improvements in continence or pelvic floor muscle function among women who had had an episiotomy compared with those who had not.
Sexual function (KQ5).
No substantive differences in sexual function at follow-up were found between women who had had an episiotomy and those who had not.