Introduction and hypothesis: This study was conducted to evaluate the effects of an alternative model of birth (AMB) on the incidence of assisted vaginal delivery (AVD) and perineal trauma (PT).
Methods: One hundred ninety-nine women with epidural anesthesia were randomized to a traditional model of birth (TMB) (n = 96) or AMB (n = 103). Women in TMB pushed immediately after complete dilatation and delivered in lithotomy position. In AMB, women followed a postural changes protocol while they delayed pushing and used a specific lateral position for delivery.
Results: AMB was associated with a significant reduction in AVD compared with TMB (19.8% vs 42.1%, p<0.001). TMB was strongly associated with AVD (OR = 4.49; p< 0.05), which, in turn, was significantly associated with nulliparity (OR = 5.52; p<0.005) and fetal head unengaged at full dilatation (OR = 5.35; p<0.05). AMB significantly increased the intact perineum rate compared with TMB (40.3% vs 12.2%, p<0.001). Episiotomy rate was significantly reduced in AMB (21.0% vs 51.4%, p<0.001).
Conclusion: A combination of postural changes during the passive expulsive phase of labor and lateral position during active pushing time is associated with reductions in AVD and PT.