The impact of a universal late third-trimester scan for fetal growth
restriction on perinatal outcomes in term singleton births: a
prospective cohort study
Abstract
Objective To investigate perinatal mortality, morbidity and obstetric
intervention after introducing universal third-trimester ultrasound scan
for growth restriction. Design Prospective cohort study Setting
Oxfordshire (OUH), UK Population Women with a non-anomalous singleton
pregnancy undergoing pregnancy care and term delivery at OUH with an
estimated-date-of-birth between 01/Jan/2014 and 30/Sept/2019. Methods
Universal ultrasound for fetal growth restriction between 35+0 and 36+6
weeks was introduced in 2016. The outcomes of the next 18631 eligible
term pregnancies were compared, using logistic regression, with the
previous 18636 who had clinically-indicated ultrasounds only. ‘Screen
positives’ for growth restriction were managed according to a
pre-determined protocol. Main Outcome Measures Extended perinatal
mortality, a composite of mortality or encephalopathy Grade II-III, and
expedited birth. Other outcomes included composite adverse outcomes used
elsewhere, detection of birthweight (<10th centile) and birth
<39+0 weeks. Results Extended perinatal deaths decreased from
1.7/1000 to 1.2/1000 births (aOR: 0.73; 0.43 -1.25); mortality or severe
morbidity decreased from 2.9/1000 to 1.9/1000 births (OR: 0.67;
0.44-1.03). Expedited births increased from 35.2% to 37.7% (OR: 1.08;
1.04 – 1.14). Birth prior to 39+0 weeks fell 10.5% (OR 0.89: 0.85 –
0.94). Birthweight (<10th centile) detection using fetal
biometry alone was 31.4%, and rose to 40.5% if all abnormal scan
parameters were used. Conclusion Introducing a universal ultrasound for
growth restriction has limited impact on mortality and severe morbidity,
but only small increases in intervention, and less early-term birth, are
possible. The detection of birthweight (<10th c) improved
where markers of growth restriction are used.