PracticeUpdate: Conference Series

LABOUR

Second stage of labour in primiparas more common than previously thought, and reduces spontaneous vaginal deliveries Prolonged second stage of labour in primiparas has been shown to be more common than previously thought. The chance of spontaneous vaginal delivery decreases linearly with the duration of second stage, report results of a retrospective cohort study. S ophia Brismar-Wendel, PhD, of the Karolinska Institute, Stockholm, Sweden, explained that prolonged control for potential confounding factors such as body mass index, epidural, gestational week and maternal age.

second stage (>3 h/2 h with/without epidural analgesia) may increase the risk of operative vaginal delivery, emergency caesarean section and obstetric anal sphincter injury. The prevalence and effects of prolonged second stage has been scarcely reported in Sweden. Dr Brismar Wendel and colleagues set out to investigate the prevalence of prolonged second stage, mode of delivery, and risk of obstetric anal sphincter injury in primiparous women. Dr Brismar-Wendel and coinvestigators used data from computerised hospital records at a large Swedish university hospital to review the cases of primiparas who gave birth in 2013. They included 2668 women with planned vaginal delivery, singleton cephalic birth at ≥34 weeks of gestation. Of these, a fully dilated cervix was noted in the partograph of 2134. Risk of emergency caesarean section and operative vaginal delivery were calculated for women with a prolonged second stage vs those with women with a normal second stage. Risk of obstetric anal sphincter injury was calculated in women who underwent operative vaginal delivery after a prolonged second stage (n=200) and a normal second stage (n=101), and in women with spontaneous vaginal delivery with a prolonged second stage (n=500). Women who gave birth via spontaneous vaginal delivery and normal second stage were used as reference (n=1250). Multivariable logistic regression analyses with adjusted odds ratios and 95% con dence intervals were performed to

A total of 762 (28.6%) women experienced a prolonged second stage. The chance of spontaneous vaginal delivery decreased with every hour from 93.6% to 11.1% at >7 h (adjusted odds ratio 0.19, 95% CI 0.15–0.25). Compared with women who experienced a normal second stage, the adjusted odds ratio for emergency caesarean section in womenwhose second stagewas prolonged 4.80 (95% CI 2.85–8.08; 8.3% vs 1.5%) and for operative vaginal delivery was 4.32 (95% CI 3.31–5.64; 28.7% vs 7.4%). Compared with women who gave birth via spontaneous vaginal delivery and a normal second stage, adjusted odds ratios for obstetric anal sphincter injury were 1.42 (95% CI 0.95–2.12; 9.4 vs 6.6%) for women who gave birth via spontaneous vaginal delivery with a prolonged second stage, 2.05 (95% CI 1.23–3.40; 15.8%) for women with operative vaginal delivery and a normal second stage, and 4.96 (95% CI 3.34–7.36; 28.5%) for women who underwent an operative vaginal delivery with a prolonged second stage. Dr Brismar-Wendel concluded that prolonged second stage of labour in primiparas was shown to be more common than previously thought. The chance of spontaneous vaginal delivery decreased linearly with the duration of the second stage of labour. The risk of sphincter injury was almost ve times higher in operative vaginal delivery after a prolonged second stage. This information can be used in the management of the second stage and timing of operative vaginal delivery.

Dr Sophia Brismar-Wendel

" The risk of

sphincter injury was almost ve times higher in operative vaginal delivery after a prolonged second stage.

PRACTICEUPDATE CONFERENCE SERIES • RCOG World Congress 2017 8