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

Kamphof, H. D.; van Roekel, M.; Henrichs, J.; de Vreede, H.; Verhoeven, C. J.; Franx, A.; de Jonge, A.; Ganzevoort, W.; Gordijn, S. J.

Abstract

Objectives
Fetal 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 (<p10). This approach is inherently flawed because it often results in over- and underdiagnosis. Some fetuses may not be small, yet challenged with FGR while others may be constitutionally small. The anomaly ultrasound scan at 20 weeks’ gestation may be the time to set the benchmark for the individual fetus’ growth potential, and we hypothesized that the following fetal growth trajectory from then onwards may be informative of third trimester placental dysfunction. In the current study we aimed to investigate the predictive value of a slow fetal growth trajectory between 18+0-23+6 weeks’ and 32-36 weeks’ gestation in a large, low-risk population.

Methods
This was a post hoc data-analysis of the IRIS study, a Dutch nationwide cluster randomized trial assessing the (cost-)effectiveness of routine sonography in reducing SAPO. For the current analysis, we used ultrasound data from the routine anomaly scan at 18+0 to 23+6 weeks’ gestation. The second ultrasound was made between 32+0 and 36+6 weeks’ gestation. Using multilevel logistic regression, we analyzed whether SAPO were predicted by a slow fetal growth trajectory. A slow fetal growth trajectory was defined as a decline of more than 20 and/or 50 percentiles of the abdominal circumference (AC) and/or the estimated fetal weight (EFW) and as the abdominal circumference growth velocity (ACGV) below the 10th percentile (<p10) in our population. In addition, we combined these indicators of slow fetal growth with SGA: the AC/EFW <p10 and severe SGA: AC/EFW <p3 at 32+0 to 36+6 weeks’ gestation.

Results
The current sample comprised the data of 6,296 women, out of whom 82 (1.3%) newborns experienced at least one SAPO. Stand-alone declines of >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.

Conclusions
In 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.

• Journal Article Type: Article
• Acceptance Date: May 7, 2022
• Online Publication Date: May 19, 2023
• Publication Date: Dec 1, 2023
• Deposit Date: Jun 8, 2023
• Publicly Available Date: Jun 14, 2023
• Journal: Ultrasound in Obstetrics & Gynecology
• Print ISSN: 1469-0705
• Electronic ISSN: 1469-0705
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 62
• Issue: 6
• Pages: 796-804
• DOI: https://doi.org/10.1002/uog.26250
• Keywords: Fetal growth restriction, FGR, slow fetal growth, small for gestational age, SGA, growth velocity, placental insufficiency
• Public URL: https://nottingham-repository.worktribe.com/output/21363359
• Publisher URL: https://obgyn.onlinelibrary.wiley.com/doi/10.1002/uog.26250