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 following the introduction of a universal late 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 due date (EDD) of birth between 1 January 2014 and 30 September 2019. Methods Universal ultrasound for fetal growth restriction between 35+0 and 36+6 weeks was introduced in 2016. The outcomes of the next 18 631 eligible term pregnancies were compared, adjusting for covariates and time, with the previous 18 636 who had clinically indicated ultrasounds only. ‘Screen‐positives’ for growth restriction were managed according to a pre‐determined protocol which included non‐intervention for some small‐for‐gestational‐age babies. 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 low birthweight and birth from 37+0 to 38+6 weeks. Results Extended perinatal deaths decreased 27% and severe morbidity decreased 33% but neither change was statistically significant (adjusted odd ratio [aOR] 0.53, 95% confidence interval [C1] 00.18–1.56 and aOR 0.71, 95% CI 0.31–1.63). Expedited births changed from 35.2% to 37.7% (aOR 0.99, 95% CI 0.92–1.06). Birthweight (<10th centile) detection using fetal biometry alone was 31.4% and rose to 40.5% if all abnormal scan parameters were used. Conclusion Improvements in mortality and severe morbidity subsequent to introducing a universal ultrasound for growth restriction are encouraging but remain unclear. Little change in intervention is possible. The antenatal detection of low birthweight remains poor but improves where markers of growth restriction are used.

Perinatal outcome of fetuses predicted to be large‐for‐gestational age on universal third‐trimester ultrasound in non‐diabetic pregnancy

“…This was a secondary analysis of the population from the OxGRIP study, which has been described previously 10 . All women with a singleton pregnancy and an estimated due date between January 2014 and September 2019 were included.…”

Investigation and Care of a Small‐for‐Gestational‐Age Fetus and a Growth Restricted Fetus (Green‐top Guideline No. 31)

“…186 In a pragmatic screening study in nulliparous women, SGA was detected in 57% with routine third trimester USS compared with 20% with USS by clinical indication, but it is only when fetal growth velocity was combined with fetal biometry that a subset of SGA fetuses at risk of increased neonatal morbidity was identified. 187 Studies published since the NICE review have similarly demonstrated an unclear effect on perinatal mortality, 188,189 and a systematic review of diagnostic performance concluded that for a fixed 10% false positive rate sensitivity was higher for AC than EFW and better performance when the scan was carried out near term and to detect FGR rather than SGA. 190 The NICE committee did note that the evidence in their review was overall moderate to low quality and that within their recommendation not to offer routine third trimester USS there is an inherent assumption that risk assessment and selective scanning is being appropriately applied.…”

Maternal serum soluble fms-like tyrosine kinase-1–to–placental growth factor ratio distinguishes growth-restricted from non–growth-restricted small-for-gestational-age fetuses

“… 5 Ultrasound (US) estimations of fetal weight and maternal and fetal Doppler abnormalities most commonly inform the current clinical management of suspected FGR. 6 However, universal third-trimester US screening for FGR was found to be a poor predictor of perinatal morbidity and mortality 7 and the significant cost burden associated with US further limits the breadth of its application to the wider pregnancy population in both high- and low-resource healthcare settings. 8 As such, poor antenatal detection of FGR has been associated with a significant increase in stillbirths, adverse perinatal outcomes, and adult-onset complications.…”