Abstract

OBJECTIVE:

To determine the patient-related factors associated with severe perineal lacerations in nulliparous women and to evaluate the effect of episiotomy type on the risk of severe perineal tears.

STUDY DESIGN:

In all, 400 nulliparous women admitted in labor between June and December 2001 were prospectively enrolled. Maternal height, perineal length, fetal birth weight, fetal head circumference, and severe perineal lacerations (third and fourth degrees) were recorded.

RESULTS:

The rate of severe perineal lacerations was 2% (8/400); 3% with midline, 1% with mediolateral groups. In patients with severe lacerations, perineal length was significantly (p < 0.001) shorter and the head circumference of their babies in the midline significantly (p < 0.05) greater than normal, and birth weights were also significantly (p < 0.05) greater in the mediolateral group. A cut-off value for perineal length of 3.05 cm was found for severe lacerations in the midline group.

CONCLUSION:

If episiotomy is to be performed, it must be borne in mind that patients with a perineal length of < or = 3 cm have an elevated risk of severe perineal lacerations, and if clinical or ultrasound examination suggests that the fetal head is large, mediolateral episiotomy may be preferred. Otherwise, midline episiotomy must be considered.