Association of spontaneous perineal stretching during delivery with perineal lacerations

OBJECTIVE: To evaluate the effect of perineal stretching on perineal damage during vaginal delivery. STUDY DESIGN: Patients at term in active labor were included. Perineal length was measured during the active phase, second stage and 24 hours postpartum. Perineal damage was assessed before repair and 24 hours postpartum. RESULTS: Three hundred women were included. Mean perineal length during the active phase was 4.02 ± 1.07 cm, and mean stretching was 2.25 ± 1.2 cm. Of the parturients who had stretched the perineum > 150%, 40.7% required perineal repair as compared with 19.5% of parturients with less perineal stretching (p < 0.005). Significant risk factors included: age and parity, ethnicity, use of epidural, second-stage length, and perineal stretching. Stretching of > 150% remained significant in a multivariate mode (OR 2.11, p < 0.01). CONCLUSION: Second-stage perineal stretching > 150% was predictive of perineal damage. In trying to avoid unnecessary episiotomies, this method may prove helpful.