Birthing postures and birth canal lacerations.

OBJECTIVE: This study was performed to assess the differences in the birth canal lacerations following the lateral and fours posture deliveries compared with those following the supine posture deliveries.

METHODS: We examined the birth canal lacerations of our "low risk" pregnant women under the midwife-led delivery care at Japanese Red Cross Katsushika Maternity Hospital between April 2006 and March 2015.

RESULTS: There were 3826, 1754 and 719 women who delivered with supine, lateral and fours postures. The rate of no laceration in the women who delivered with lateral posture was significant lower than that in the women who delivered with supine posture (OR 0.630, 95% CI 0.56-0.71, p < 0.01); however, the incidence of perineal laceration in the women who delivered with lateral posture was significant lower than that in the women who delivered with supine posture (OR 0.856, 95% CI 0.76-0.90, p < 0.01). The incidence of perineal laceration of third- or fourth-degree in the women who delivered with fours posture was significant higher than that in the women who delivered with supine posture (OR 2.28, 95% CI 1.2-4.2, p < 0.01).

CONCLUSION: The current results may be to help for self-determination of birthing postures in prenatal women.