Prior third- or fourth-degree perineal tears and recurrence risks.

OBJECTIVE

The objective of the present study is to determine the recurrence risk of a third-degree (into the anal sphincter) or a fourth-degree (into the rectum) perineal tear in women with a prior extensive laceration.

METHODS

Data were gathered from our computerized perinatal database between January 1990 and December 1994. Women who had two consecutive singleton deliveries were chosen as subjects.

RESULTS

The rate of an extensive perineal laceration was greater if a tear had occurred in a previous pregnancy (19 of 178 cases, 10.7% vs. 56% of 1563 cases, 3.6%, odds ratio 3.4. A 95% confidence interval: 1.8-6.4; p < 0.0001). A prior tear remained a risk factor after controlling for other variables (epidural analgesia, episiotomy, oxytocin use, operative vaginal delivery, fetal macrosomia).

CONCLUSION

A prior third-degree or fourth-degree perineal tear is associated with a 3.4-fold increased risk of a recurrent severe obstetrical laceration.