Fetal malposition: using manual rotation to improve delivery outcomes

Backgound: Fetal malposition in labour is a major risk factor for both caesarean section and instrumental delivery. Manual rotation, in the second stage of labour, represents one promising method of reducing operative delivery. Objectives: To review the literature on the efficacy of manual rotation for fetal malposition in the second stage of labour, assess current clinical practice and explore the feasibility of undertaking a randomised controlled trial of prophylactic manual rotation for reducing operative delivery. Methodology Meta-analysis of randomised controlled trials (RCT) using Cochrane. National Survey of Midwives and Obstetricians to determine current management. Pilot blinded RCT re feasibility of undertaking a trial. Design of a multi-centred blinded RCT to reduce operative delivery. Results: Obstetricians and midwives use manual rotation infrequently but are confidence in its efficacy. An RCT is feasible. Occiput transverse position is associated with increased rates of operative delivery. Intrapartum consent improves recruitment. There is a need for a birth mannequin to facilitate clinicians training in performing manual rotation, which has been designed. Two randomised controlled trials are in progress. Conclusions: Multiple research projects have been performed, which have led to the development of two RCT protocols and two multi-centred randomised controlled trials (one is NHMRC funded) are currently in progress

The identification and tracking of uterine contractions using template based cross-correlation

The purpose of this paper is to outline a novel method of using template based cross-correlation to identify and track uterine contractions during labour. A purpose built six-channel Electromyography (EMG) device was used to collect data from consenting women during labour and birth. A range of templates were constructed for the purpose of identifying and tracking uterine activity when cross-correlated with the EMG signal. Peak finding techniques were applied on the cross-correlated result to simplify and automate the identification and tracking of contractions. The EMG data showed a unique pattern when a woman was contracting with key features of the contraction signal remaining consistent and identifiable across subjects. Contraction profiles across subjects were automatically identified using template based cross-correlation. Synthetic templates from a rectangular function with a duration of between 5 and 10 s performed best at identifying and tracking uterine activity across subjects. The successful application of this technique provides opportunity for both simple and accurate real-time analysis of contraction data while enabling investigations into the application of techniques such as machine learning which could enable automated learning from contraction data as part of real-time monitoring and post analysis

Impact of analysis technique on our understanding of the natural history of labour : a simulation study

Objective: To evaluate the discrepancy between historical and more recent descriptions of the first stage of labour by testing whether the statistical techniques used recently (repeated-measures polynomial and interval-censored regression) were appropriate for detection of periods of rapid acceleration of cervical dilatation as might occur at the time of transition from a latent to an active phase of labour. Design and setting: A simulation study using regression techniques. Sample We created a simulated data set for 500 000 labours with clearly defined latent and active phases using the parameters described by Friedman. Additionally, we created a data set comprising 500 000 labours with a progressively increasing rate of cervical dilatation. Methods: Repeated-measures polynomial regression was used to create summary labour curves based on simulated cervical examinations. Interval-censored regression was used to create centimetre-by-centimetre estimates of rates of cervical dilatation and their 95th centiles. Main outcome measures Labour summary curves and rates of cervical dilatation. Results: Repeated-measures polynomial regression did not detect the rapid acceleration in cervical dilatation (i.e. acceleration phase) and overestimated lengths of labour, especially at smaller cervical dilatations. There was a two-fold overestimation in the mean rate of cervical dilatation from 4 to 6 cm. Interval-censored regression overestimated median transit times, at 4- to 5-cm cervical dilatation or when cervical examinations occurred less frequently than 0.5- to 1.5-hourly. Conclusion: Repeated-measures polynomial regression and inter-valcensored regression should not be routinely used to define labour progress because they do not accurately reflect the underlying data

The association between induction of labour at 38 to 39 weeks pregnancy and indication for caesarean delivery: An observational study

Background: Induction of labour is associated with a reduction in caesarean delivery, but the mechanism of action and which groups of women might benefit remain unknown. Aims: To assess the association between induction of labour at 38–39 weeks pregnancy, and caesarean delivery: (i) overall; (ii) for slow progress in labour; and (iii) for suspected fetal compromise. Material and methods: Retrospective observational study in two Sydney hospitals from 2009 to 2016, among nulliparous women with induction of labour at 38 or 39 completed weeks pregnancy and a singleton, cephalic presenting fetus. The comparator was all planned vaginal births beyond 39(+1/7) weeks, whether or not labour was induced. Binary and multinomial multiple logistic regressions adjusting for multiple confounders were performed. Results: There were 2388 and 15 259 women in the study and comparison groups respectively. Induction of labour was associated with caesarean delivery overall only for women <25 years of age (adjusted odds ratio 1.63; 95% CI 1.17–2.27) and was not associated with caesarean delivery for slow progress. Induction of labour was positively associated with increased caesarean delivery for suspected fetal compromise among young women (<30 years), with the association weakening as maternal age increased. The association between induction of labour and caesarean delivery was different for slow progress compared with suspected compromise (P = 0.005). Conclusions: Induction of labour has different effects on the likelihood of caesarean delivery for slow progress and for suspected fetal compromise. Women <30 years of age are at higher risk of caesarean delivery for suspected fetal compromise, potentially due to uterine hyperstimulation