Dr Jenny Myers: Prediction and prevention of adverse pregnancy outcomes in woman with chronic vascular disease

In 2012 clinicians from The Manchester Antenatal Vascular Service (MAViS) based at St Mary’s Hospital Manchester, were successfully awarded an NIHR Clinician Scientist Award. The grant totalling £915,000 was achieved with the support of the RDS NW following an advice request from the Chief Investigator, Dr Jenny Myers.  The RDS offers free specialist advice on all aspects of an application and in this case were able to assist with the design of the prospective study which sought to investigate the clinical utility of measuring blood vessel relaxation using a highly sensitive blood pressure machine.

This pilot trial will assess the efficacy, safety and acceptability of targeted therapy. The clinic with its unique specialist research capability already had the necessary personnel, equipment and facilities to conduct this study.

Background to this study showed that chronic hypertension complicates two percent of pregnancies in the UK and is therefore associated with increased maternal and perinatal morbidity. In addition recent National Institute for Health and Care Excellence (NICE) guidelines have highlighted the need to investigate the safety and efficacy of antihypertensive treatment in pregnancy. In women with a history of hypertension, blood vessel function is altered and in contrast to healthy pregnancies, the blood vessels

do not relax during pregnancy. This abnormal adaptation is associated with an increased risk of developing pre-eclampsia and/or fetal growth restriction; both of which often necessitate a premature delivery. Therefore this prospective study based on trial design advice provided by the RDS NW will investigate the clinical utility of measuring blood vessel relaxation using a highly sensitive blood pressure machine. The accuracy of blood vessel relaxation in the prediction of preterm pregnancy complications will be assessed and used to recruit women to a pilot randomised controlled trial. The trial will involve the prescription of a commonly used blood pressure tablet (nifedipine) to normalise blood vessel relaxation in women with chronic hypertension.