Unisex and Sex-Specific Prescriptive Fetal Growth Charts for Improved Detection of Small-for-Gestational-Age Babies in a Low-Risk Population: A post hoc Analysis of a Cluster-Randomized Study

van Roekel, Mariëlle; Verhoeven, Corine J.; Kamphof, Hester D.; Gordijn, Sanne J.; Ganzevoort, Wessel; Franx, Arie; van Wieringen, Wessel; de Jonge, Ank; Henrichs, Jens

Abstract

Introduction: Our aim was to develop and evaluate the performance of population-based sex-specific and unisex prescriptive fetal abdominal circumference growth charts in predicting small-for-gestational-age (SGA) birthweight, severe SGA (sSGA) birthweight, and severe adverse perinatal outcomes (SAPO) in a low-risk population. Methods: This is a post hoc analysis of the Dutch nationwide cluster-randomized IRIS study, encompassing ultrasound data of 7,704 low-risk women. IRIS prescriptive unisex and IRIS sex-specific abdominal circumference (AC) fetal growth charts were derived using quantile regression. As a comparison, we used the descriptive unisex Verburg chart, which is commonly applied in the Netherlands. Diagnostic parameters were calculated based on the 34–36 weeks’ ultrasound. Results: Sensitivity rates for predicting SGA and sSGA birthweights were more than twofold higher based on the IRIS prescriptive sex-specific (respectively SGA 43%; sSGA 59%) and unisex (SGA 39%; sSGA 55%) charts, compared to the Verburg chart (SGA 16%; sSGA 23% both p < 0.01). Specificity rates were highest for Verburg (SGA 99%; sSGA 98%) and lowest for IRIS sex-specific (SGA 94%; sSGA 92%). Results for predicting SGA with SAPO were similar for the prescriptive charts (44%), and again higher than the Verburg chart (20%). The IRIS sex-specific chart identified significantly more males as SGA and sSGA (respectively, 42%; 60%, p < 0.001) than the IRIS unisex chart (respectively, 35%; 53% p < 0.01). Conclusion: Our study demonstrates improved performance of both the IRIS sex-specific and unisex prescriptive fetal growth compared to the Verburg descriptive chart, doubling detection rates of SGA, sSGA, and SGA with SAPO. Additionally, the sex-specific chart outperformed the unisex chart in detecting SGA and sSGA. Our findings suggest the potential benefits of using prescriptive AC fetal growth charts in low-risk populations and emphasize the importance of considering customizing fetal growth charts for sex. Nevertheless, the increased sensitivity of these charts should be weighed against the decrease in specificity.

Citation

van Roekel, M., Verhoeven, C. J., Kamphof, H. D., Gordijn, S. J., Ganzevoort, W., Franx, A., van Wieringen, W., de Jonge, A., & Henrichs, J. (2024). Unisex and Sex-Specific Prescriptive Fetal Growth Charts for Improved Detection of Small-for-Gestational-Age Babies in a Low-Risk Population: A post hoc Analysis of a Cluster-Randomized Study. Fetal Diagnosis and Therapy, 51, 571-582. https://doi.org/10.1159/000540554

• Journal Article Type: Article
• Acceptance Date: Jul 22, 2024
• Online Publication Date: Jul 26, 2024
• Publication Date: Jul 26, 2024
• Deposit Date: Sep 19, 2024
• Publicly Available Date: Sep 27, 2024
• Journal: Fetal Diagnosis and Therapy
• Print ISSN: 1015-3837
• Electronic ISSN: 1421-9964
• Publisher: Karger Publishers
• Peer Reviewed: Peer Reviewed
• Volume: 51
• Pages: 571-582
• DOI: https://doi.org/10.1159/000540554
• Public URL: https://nottingham-repository.worktribe.com/output/39725934
• Publisher URL: https://karger.com/fdt/article/doi/10.1159/000540554/910769/Unisex-and-Sex-Specific-Prescriptive-Fetal-Growth