Objective To describe the trends of severe perineal tears in England and to investigate to what extent the changes in related risk factors could explain the observed trends.Design A retrospective cohort study of singleton deliveries from a national administrative database.Setting The English National Health Service between 1 April 2000 and 31 March 2012.Population A cohort of 1 035 253 primiparous women who had a singleton, term, cephalic, vaginal birth.Methods Multivariable logistic regression was used to estimate the impact of financial year of birth (labelled by starting year), adjusting for major risk factors.Main outcome measure The rate of third-degree (anal sphincter is torn) or fourth-degree (anal sphincter as well as rectal mucosa are torn) perineal tears.Results The rate of reported third-or fourth-degree perineal tears tripled from 1.8 to 5.9% during the study period. The rate of episiotomy varied between 30 and 36%. An increasing proportion of ventouse deliveries (from 67.8 to 78.6%) and non-instrumental deliveries (from 15.1 to 19.1%) were assisted by an episiotomy. A higher risk of third-or fourth-degree perineal tears was associated with a maternal age above 25 years, instrumental delivery (forceps and ventouse), especially without episiotomy, Asian ethnicity, a more affluent socio-economic status, higher birthweight, and shoulder dystocia.Conclusions Changes in major risk factors are unlikely explanations for the observed increase in the rate of third-or fourth-degree tears. The improved recognition of tears following the implementation of a standardised classification of perineal tears is the most likely explanation.Keywords Episiotomy, instrumental delivery, severe perineal trauma, trends, vaginal delivery.

Further research is needed to reduce the impact of selection bias by indication through creating more comparable patient groups and applying risk adjustment.

Objectives To investigate the demographic and obstetric factors associated with the uptake and success rate of vaginal birth after caesarean section (VBAC).Design Cohort study using data from Hospital Episode Statistics.Setting English National Health Service.Population Women whose first birth resulted in a live singleton delivery by caesarean section between 1 April 2004 and 31 March 2011, and who had a second birth before 31 March 2012. Methods Logistic regression to estimate adjusted odds ratios (OR).Main outcome measures Attempted and successful VBAC.Results Among the 143 970 women in the cohort, 75 086 (52.2%) attempted a VBAC for their second birth.Younger women, those of non-white ethnicity and those living in a more deprived area had higher rates of attempted VBAC. Overall, 47 602 women (63.4%) who attempted a VBAC had a successful vaginal birth. Younger women and women of white ethnicity had higher success rates. Black women had a particularly low success rate (OR, 0.54; 95% confidence interval [CI], 0.50-0.57). Women who had an emergency caesarean section in their first birth also had a lower VBAC success rate, particularly those with a history of failed induction of labour (OR, 0.59; 95% CI, 0.53-0.67). ConclusionIn this national cohort, just over one-half of women with a primary caesarean section who were eligible for a trial of labour attempted a VBAC for their second birth. Of these, almost two-thirds successfully achieved a vaginal delivery.Keywords Administrative data, England, trial of labour, vaginal birth after caesarean.Please cite this paper as: Knight HE, Gurol-Urganci I, van der Meulen JH, Mahmood TA, Richmond DH, Dougall A, Cromwell DA. Vaginal birth after caesarean section: a cohort study investigating factors associated with its uptake and success. BJOG 2014;121:183-193.

This study demonstrates that in the absence of feedback, it is not possible to improve performance on the HT Immersion Medical Colonoscopy Simulator. Thus, there is no learning curve for the machine. The information from this study is vital for using the simulators in training and assessment because any improvement in learning curves shown after training on simulators can be presumed to be due to learning the procedure and not the simulator.

Objective To investigate, among women who have had a third-or fourth-degree perineal tear, the mode of delivery in subsequent pregnancies as well as the recurrence rate of third-or fourth-degree tears.Design A retrospective cohort study of deliveries using a national administrative database. Methods Multivariable logistic regression models were used to estimate odds ratios, adjusted for other risk factors.Main outcome measures Mode of delivery and recurrence of tears at second birth.Results The rate of elective caesarean at second birth was 24.2% for women with a third-or fourth-degree tear at first birth, and 1.5% for women without (adjusted odds ratio, aOR 18.3, 95% confidence interval, 95% CI 16.4-20.4). Among women who had a vaginal delivery at second birth, the rate of third-or fourth-degree tears was 7.2% for women with a third-or fourth-degree tear at first birth, compared with 1.3% for women without (aOR 5.5, 95% CI 5.2-5.9).Conclusions The risk of a severe perineal tear is increased five-fold in women who had a third-or fourth-degree tear in their first delivery. This increased risk should be taken into account when decisions about mode of delivery are made.