Does performing fetal ultrasound assessment once versus twice in the third trimester in low risk women alter the stillbirth rate?

The aim of this retrospective observational study was to evaluate if performing fetal growth scans once or twice in the third trimester impacts on stillbirth rates in low risk pregnancies. The study was performed in a tertiary centre with 6,000 deliveries per annum. Data on all deliveries was collected via the National Maternity System Database and high risk pregnancies were excluded to calculate the stillbirth rate before and after 2011 when ultrasound assessment was performed twice and once in the third trimester. Between 2009-2012 there were 18,856 low risk-pregnancy deliveries with 45 stillbirths, (average stillbirth rate 0.26%). The stillbirth rate in 2009/2010 was 54/9423 (0.25%). The stillbirth rate in 2012 was 13/5615 (0.27%). [p = 0.897; chi square = 0.017; df = 1]. There was no statistical difference in the stillbirth rate when low risk women were scanned once or twice in the third trimester.