Analysis of routinely collected data to contribute to our understanding of fetal growth trajectories and the factors associated with growth resulting in babies becoming ‘growth restricted’.
Mr Lawrence Impey, Oxford University Hospitals NHS Foundation Trust
Impaired placental function or ‘growth restriction’ is present in ~50% of stillbirths and has long term health consequences for growth restricted babies who are born alive. One manifestation of growth restriction is being born ‘small for gestational age’ (SGA). In the UK, and Thames Valley region, only 35% of growth restricted babies are detected antenatally; as a consequence improved detection is the subject of a national service improvement initiative (Saving Babies Lives, NHS England, 2016). Detection of these babies is possible using ultrasound, but this is expensive and there is a shortage of sonographers. Ad hoc targeting of ultrasound scanning is common and the proportion of women who have growth ultrasound scans differ widely between different hospitals; national guidelines and initiatives such as GROW aim to target at risk pregnancies but are complex, controversial, partly because they lack a robust evidence base, and require vastly increased use of ultrasound. Furthermore, they have demonstrated only very limited benefit. A further problem is that most SGA babies are not actually pathologically ‘growth restricted’ or at risk: they were simply meant to be constitutionally small. Yet national guidelines advise induction of labour at 37 weeks for all babies identified as ‘small for gestational age’. A major risk of this is the potential for increased obstetric intervention, with the consequent maternal and neonatal morbidity. The latter could be a major contributor to the recent increase in admission rates of term babies to neonatal units.
Of even greater concern is that the currently unachieved detection of SGA babies will have only a minor effect on stillbirth rates. This is because many ‘growth restricted’ babies are not small for gestational age; they are merely smaller than they were meant to be or have late or less chronic placental malfunction. Current research suggests that assessment of growth velocity and fetal/placental blood flow may help identify these babies but this is not widely used. This all means that current recommendations increase both resource usage and obstetric intervention, yet fail to identify the most at risk babies who might benefit from early intervention and delivery.
At the Oxford University Hospitals (OUH) NHS Foundation Trust, with approx. 8,000 births per year, a service initiative has been developed that involves universal, structured risk assessment at 20 weeks, a routine 36 week growth scan with more complex assessment (unique in the UK), structured referral for investigation according to pre-set criteria for abnormality at this scan, and conservative (i.e. non induction) management of apparently well, but SGA babies.
Although a service initiative, the project is generating large amounts of new data from an unselected population. Ultrasound details have been merged with antenatal demographics, adverse outcomes and neonatal outcomes. There is therefore the potential for a large number of research projects concerning the important area of fetal growth. Further, the service initiative requires complex evaluation; if significant improvements are seen it could form the basis for a substantial change in pathways of care to improve the detection and management of intra uterine growth restriction.
The following project is offered which will require further development with a prospective student:
Analysis of routinely collected data to contribute to our understanding of fetal growth trajectories and the factors associated with growth resulting in babies becoming ‘growth restricted’. Examples of this are construction of ‘normal’ ranges for ultrasound parameters and growth trajectories, the correlation of ultrasound parameters, and of multiple clinical risk factors (e.g. carbon monoxide levels), with adverse outcomes.
RESEARCH EXPERIENCE, RESEARCH METHODS AND TRAINING
The student will work within a large multidisciplinary research and clinical team and will gain research experience in research design, epidemiological and statistical methods, programming, data analysis, scientific writing and dissemination of findings at scientific meetings.
The project will be based in the 1National Perinatal Epidemiology Unit in the Nuffield Department of Public Health in collaboration with the 2Department of Obstetrics and Fetal Medicine at the Oxford University Hospitals NHS Foundation Trust. The student will therefore have the benefit of a thriving and stimulating research and clinical environment with excellent research and clinical supervision.
field work, secondments, industry placements and training
The project will provide an extensive range of training opportunities through attending specific courses, meetings, seminars, workshops and conferences. Through the clinical supervision the outcomes of these projects will have a direct effect on clinical practice.
These projects will require someone with a particular interest and skills in statistical analysis and would best suit someone with a higher degree in statistics, epidemiology or a related discipline with a strong statistical component.