Labour and delivery
What triggers labour
Dr Penny Sheehan, Prof Shaun Brennecke
The process of birth is thought to be controlled by hormonal factors produced by tissues within the womb. The aim of this project is to investigate one of these hormones, in particular, a metabolite of progesterone called 5-beta-dihydroprogesterone. This study will help to improve our understanding of how normal labour occurs and may provide insight into how to prevent it from occurring prematurely. Blood samples are collected from women before, during and after labour, and also from women in premature labour and before term but not in labour. Tissue samples from the womb are also collected at the delivery of babies by Caesarean section for investigation using various molecular biology techniques.
Prediction and prevention of preterm labour
Dr Penny Sheehan, Prof David Smith, Prof Shaun Brennecke
A number of factors are known to be associated with increased risk of preterm labour including the presence of certain microorganisms and the length of the cervix as measured by transvaginal ultrasound. Women known to be at higher risk of preterm labour are offered care through the preterm labour clinic. Data obtained from women attending the clinic will be used to investigate the possibility of predicting preterm labour through the development of a computer program which provides and individual risk assessment. Interventions such as cervical cerclage and vaginal progesterone supplementation to prevent preterm labour are studied through the clinic.
Failure to progress in labour - electrophysiological and molecular studies
Prof Helena Parkington, Dr Penny Sheehan, Prof Shaun Brennecke
Failure of the muscle of the uterus to contract strongly during labour results in protracted and exhausting labour and, in a significant percentage of cases, necessitates caesarian delivery. The aim of this study is to elucidate the mechanisms that may be responsible for the weak uterine contractions that underlie ineffective labour. Failure of the uterus to contract normally at term, ineffective labour, necessitates the intervention of caesarian delivery in as many as 5-10% of first pregnancies. Administration of oxytocin may augment weak uterine contractions and resolve ineffective labour in some cases. However, in many cases, successful vaginal delivery is not achieved by oxytocin infusion. The causes of ineffective labour remain obscure. In our recent studies of uterine contractility in tissues form a subset of the in-labour group appeared to divide the ineffective labour tissues further into three groups. One group contracted weakly to applied oxytocin. In another group, contractions were anomalously suppressed by prostaglandins that are normally strongly excitatory. The smooth muscle cells in tissues of the third group had unusually negative transmembrane potentials, making contractions difficult to achieve in the face of a wide range of stimuli. Elucidation of the mechanisms underpinning the failure to contract by these tissue is the main aim of this project