Optimal time intervals for vaginal breech births: a case-control study

Abstract

Background: Breech births are associated with a high rate of hypoxic injury, in part due to cord occlusion during emergence. Maximum time intervals and guidelines oriented toward earlier intervention have been proposed in a Physiological Breech Birth Algorithm. We wished to further test and refine the Algorithm for use in a clinical trial. Methods: We conducted a retrospective case-control study in a London teaching hospital, including 15 cases and 30 controls, during the period of April 2012 to April 2020. Our sample size was powered to test the hypothesis that exceeding recommended time limits is associated with neonatal admission or death. Data collected from intrapartum care records was analysed using SPSS v26 statistical software. Variables were intervals between the stages of labour and various stages of emergence (presenting part, buttocks, pelvis, arms, head). The chi-square test and odds ratios were used to determine association between exposure to the variables of interest and composite outcome. Multiple logistic regression was used to test the predictive value of delays defined as non-adherence the Algorithm. Results: Logistic regression modelling using the Algorithm time frames had an 86.8% accuracy, a sensitivity of 66.7% and a specificity of 92.3% for predicting the primary outcome. Delays between umbilicus and head >3 minutes (OR: 9.508 [95% CI: 1.390-65.046] p=0.022) and from buttocks on the perineum to head >7 minutes (OR: 6.682 [95% CI: 0.940-41.990] p=0.058) showed the most effect. Lengths of time until the first intervention were consistently longer among the cases. Delay in intervention was more common among cases than head or arm entrapment. Conclusion: Emergence taking longer than the limits recommended in the Physiological Breech Birth algorithm may be predictive of adverse outcomes. Some of this delay is potentially avoidable. Improved recognition of the boundaries of normality in vaginal breech births may help improve outcomes.

How safe is it to plan a vaginal breech birth with OptiBreech collaborative care?: analysis of cumulative data within the OptiBreech Multiple Trials Cohort

“…Detailed observational work also theoretically underpins our practice guidelines, including video analysis and case control studies to define ranges of 'normal' in breech births [8][9][10] . The OptiBreech Algorithm aims to reduce the leading cause of breech birth-related injury: asphyxia [8][9][10] . Our team has raised concerns previously that current guidelines are not optimally safe 10,35 .…”

“…The OptiBreech Algorithm aims to reduce the leading cause of breech birth-related injury: asphyxia [8][9][10] . Our team has raised concerns previously that current guidelines are not optimally safe 10,35 . Historically, breech practice has not been based on evidence, particularly around the expected time intervals as the breech baby emerges 8 .…”

“…Twelve percent of obstetrics claims for cerebral palsy relate to poorly managed VBBs, despite representing only 0.3% of total births 7 . Our team developed an evidence-based management algorithm that aims to reduce the leading cause of breech birth-related injury: asphyxia [8][9][10] .…”

Breech specialist midwives and clinics in the OptiBreech Trial feasibility study: An implementation process evaluation

“…2,3 Interventions are performed in response to specific clinical indications based on evidence of what is considered "normal" breech birth physiology. [4][5][6] Neither upright maternal positioning nor this approach has been tested in a clinical trial.…”

“…This includes upright maternal birth positions, such as kneeling, which promote active maternal movement and efficiency during expulsion 2,3 . Interventions are performed in response to specific clinical indications based on evidence of what is considered “normal” breech birth physiology 4–6 . Neither upright maternal positioning nor this approach has been tested in a clinical trial.…”