While there are identifiable trends in pessary use, there is no clear consensus regarding the indications for support pessaries compared with space-filling pessaries, or the use of a single pessary for all support defects compared with tailoring the pessary to the specific defect. Randomized clinical trials are needed to define optimal pessary use.

Levator ani hernias are often missed by physical examination and traditional fluoroscopic imaging. Dynamic magnetic resonance and cystocolpoproctography are complementary studies to the physical examination that may alter the surgical management of females with complex pelvic floor disorders.

Objective: This study sought to quantify perinatal and maternal morbidity and mortality associated with forceps and vacuum delivery compared with Caesarean delivery in the second stage of labour and to estimate whether these associations differed by pelvic station. Methods: The investigators conducted a population-based, retrospective cohort study of term singleton deliveries by operative delivery with prolonged second stage of labour in Canada (2003-2013) using national hospitalization data. The primary study outcomes were severe perinatal morbidity and mortality (i.e., seizures, assisted ventilation, severe birth trauma, and perinatal death) and severe maternal morbidity and mortality (i.e., severe postpartum hemorrhage, cardiac complication, and maternal death). Logistic regression was used to estimate adjusted odds ratios (aOR) and 95% confidence intervals (CI) after stratifying by indication (dystocia or fetal distress). The Breslow-Day chi-square test for heterogeneity in ORs was used to test effect modification by pelvic station (outlet, low, or midpelvic). Results: There were 61 106 deliveries included in the study. Among women with dystocia, forceps and vacuum deliveries were associated with higher rates of perinatal morbidity and mortality compared with Caesarean delivery (forceps: aOR 1.56; 95% CI 1.13À2.17; vacuum: aOR 1.44; 95% CI 1.06À1.97). Vacuum delivery was associated with lower rates of maternal morbidity and mortality compared with Caesarean delivery (dystocia: aOR 0.64; 95% CI 0.51À0.81; fetal distress: aOR 0.43; 95% CI 0.32À0.57). Pelvic station did not significantly modify the associations between forceps or vacuum and perinatal or maternal morbidity and mortality. Conclusion: Forceps and vacuum delivery is associated with increased rates of severe perinatal morbidity and mortality compared with Caesarean delivery among women with dystocia, whereas vacuum delivery is associated with decreased rates of severe maternal morbidity and mortality.

T he increase in cesarean delivery over the past several decades has occurred concomitantly with a decline in operative vaginal deliveries. In the United States, operative vaginal delivery rates decreased from 9.4% in 1995 to 3.1% of all deliveries in 2015, whereas cesarean delivery rates increased from 20.8% to 32.0%.1,2 In Canada as well, rates of operative vaginal delivery followed the same downward trajectory, from 16.8% of all vaginal deliveries in 1995 to 13.2% in 2014, 3,4 whereas cesarean delivery rates increased from 17.6% to 27.3% of all deliveries. This inverse relationship has led to recommendations for increasing rates of operative vaginal delivery as a solution for addressing the high rates of cesarean delivery. 5Such recommendations for addressing increases in cesarean delivery are premised on the assumption that operative vaginal delivery has greater relative safety compared with cesarean delivery. However, recent studies 6-9 have shown higher rates of severe perinatal and maternal adverse outcomes after operative vaginal delivery. In particular, our previous work 6,7 showed substantially higher rates of obstetric trauma among midpelvic forceps and vacuum deliveries, compared with cesarean deliveries (adjusted rate ratio [ARR] 8.48, 95% confidence interval [CI] 7.22-9.96 and 6.90, 95% CI 5.86-8.13, respectively). The ARRs for severe birth trauma were 4.33, 95% CI 2.31-8.11 for forceps and 3.16, 95% CI 1.65-6.05 for vacuum versus cesarean delivery.7 Nevertheless, the populationlevel impact of increasing the rate of operative vaginal delivery on obstetric and birth trauma rates has not been quantified.We sought to characterize temporal trends in obstetric trauma and severe birth trauma in Canada, by mode of delivery, by operative instrument (i.e., forceps or vacuum) and by pelvic station (outlet, low or midpelvic). We also aimed to quantify the associations between population rates of operative vaginal delivery and obstetric trauma and severe birth trauma. MethodsWe obtained data on all hospital deliveries in 4 Canadian provinces -Alberta, Manitoba, Ontario and Saskatchewan -from the Canadian Institute for Health Information's Discharge Abstract Database. ABSTRACT BACKGROUND: Increased use of operative vaginal delivery (use of forceps, vacuum or other device) has been recommended to address high rates of cesarean delivery. We sought to determine the association between rates of operative vaginal delivery and obstetric trauma and severe birth trauma. RESEARCH Ecological association between operative vaginal delivery and obstetric and birth trauma