Around 700,000 women become pregnant every year in the UK. The vast majority of pregnant women are described as ‘low risk’ at booking and the methods used for assessing their risk as pregnancy progresses have remained largely unchanged over the last 30 years. Briefly, standard antenatal care for low-risk women involves a series of blood and urine screening tests, a dating scan at 12 weeks, an anomaly scan at 20 at weeks, and the use of a tape measure to calculate what’s known as the fundal height measurement which will tell clinicians whether the baby is growing well.
Many ‘low risk’ parents tell us, when their baby dies near term, that they would like to have had more scans. Parents of babies whose deaths are unexplained often feel their babies were not adequately monitored, especially in the last third of pregnancy, and could have been saved.
The difficulty has been that previous research trials of routine fetal biometry (an ultrasound measurement which calculates the baby’s gestation in relation to its dimensions) and utero-placental Doppler (which determines blood flow from the mother to baby via the placenta) have not shown an improvement in predicting or preventing poor perinatal outcome.
However, these trials were designed without reliable information on whether they might work as a screening test for stillbirth or a condition associated with stillbirth, such as a small for gestational age (SGA) baby - that’s a baby whose growth is below the 10th centile. We know that SGA babies are at greater risk of stillbirth.
Without good evidence that extra scans improve outcomes, screening policies for low risk pregnancies will not change. It’s time therefore to revisit this important area of care.
What is the project trying to achieve?
Gordon C S Smith, Professor of Obstetrics and Gynaecology, Head of Department, Cambridge University, the Principal Investigator in this study has already been conducting a large piece of research – recruiting more than 4000 first time mothers - to determine new biomarkers (biological markers) in the mother’s blood which may predict adverse pregnancy outcome. This on-going study has generated more than 12,000 research ultrasound scans.
Analysing these data will allow the group to determine the ability of routine ultrasound to predict delivery of a small for gestational age infant in first pregnancies that is a proxy for stillbirth. Impaired growth in the baby is thought to contribute to 25-30% of all stillbirths.
Who is conducting the research?
The Principal Investigator on the project is Gordon C S Smith, Professor of Obstetrics and Gynaecology, Head of Department, Cambridge University. Dr Angela Wood, Lecturer in Biostatistics, Department of Health will work alongside him.
It is taking place at The Rosie Hospital, Cambridge University.
This is a two year project running from 2013-2015.
1. Smith GCS. First trimester determination of complications of late pregnancy. JAMA 2010;303:561-562.
2. Pasupathy D, Wood AM, Pell JP, Fleming M, Smith GCS. Rates of and factors associated with delivery-related perinatal death among term infants inScotland. JAMA 2009;302:660-668.
3. Smith GCS, Fretts R. Seminar: Stillbirth. Lancet 2007;370: 1715-25.
4. Smith GCS, Crossley JA, Aitken DA, Pell JP, Cameron AD, Connor JM, Dobbie R. First trimester placentation and the risk of antepartum stillbirth. JAMA 2004; 292:2249-2254.