Predictive value of fetal growth trajectory from 20 weeks of gestation onwards for severe adverse perinatal outcomes in low‐risk population: secondary analysis of IRIS study

ObjectivesFetal growth restriction (FGR) remains a challenging condition in diagnosis and monitoring-management strategies. The underlying placental dysfunction may result in severe adverse perinatal outcomes (SAPO) related to fetal hypoxia. The traditional diagnostic criteria for FGR are based on fetal size: small-for-gestational-age (SGA), with a cut-off below the 10th percentile (20 or >50 percentiles of the AC and/or the EFW and ACGV <p10 were not associated with increased odds of SAPO. EFW <p10 between 32+0 and 36+6 weeks’ gestation and a decline of the EFW of more than 20 percentiles was associated with an increased rate of SAPO. The combination of AC or EFW <p10 between 32+0 and 36+6 weeks’ gestation with ACGV <p10 were also associated with increased odds of SAPO. The odds ratios of these associations were higher if the neonate was SGA at birth.ConclusionsIn a low-risk population, slow fetal growth trajectory as a stand-alone criterium does not adequately distinguish between growth-restricted fetuses and constitutionally small fetuses. This absence of associations may be the result of diagnostic inaccuracies and/or from post-diagnostic (e.g., intervention and selection) biases. We conclude that new approaches to detect placental insufficiency should integrate the risks of the various informative diagnostic tools