10.6084/m9.figshare.5097331.v1 Basuki T.R. Basuki T.R. Triunfo S. Triunfo S. Caradeux J. Caradeux J. Eixarch E. Eixarch E. Hansson S. Hansson S. Gratacos E. Gratacos E. Figueras F. Figueras F. Supplementary Material for: Third-Trimester Conditional Reference Values for Longitudinal Fetal Growth Assessment Karger Publishers 2017 Estimated fetal weight Abdominal circumference Gestational age Longitudinal study Multilevel modeling Conditional reference values 2017-06-09 10:00:22 Journal contribution https://karger.figshare.com/articles/journal_contribution/Supplementary_Material_for_Third-Trimester_Conditional_Reference_Values_for_Longitudinal_Fetal_Growth_Assessment/5097331 <p><b><i>Objectives:</i></b> The aim of this study was to derive longitudinal reference values of fetal growth (estimated fetal weight [EFW] and abdominal circumference [AC]) during the third trimester and to develop coefficients for conditional growth assessment. <b><i>Patients and Methods:</i></b> A prospective cohort study was conducted involving consecutive singleton pregnancies in a low-risk population for a routine third-trimester scan at 30<sup>+0</sup>-34<sup>+6</sup> weeks and follow-up at 37<sup>+0</sup>-38<sup>+6</sup> weeks for an additional ultrasound. Statistical analysis was based on multilevel modeling using MLwiN software. Unconditional centiles were calculated from z-values at each gestational age, and conditional centiles were calculated from z-values at a given measurement (30-34 weeks) and the expected measurement (37-38 weeks). <b><i>Results:</i></b> At 30-34 weeks, 8 and 9.3% of the fetuses had an unconditional EFW below the 10th and above the 90th centile, respectively. At 37-38 weeks, these figures were 10.3 and 9.3%, respectively. Regarding the unconditional AC, at the first scan, 8.9 and 9.6% had values below the 10th and above the 90th centile, while at the second scan 10.5 and 10.5% had values below the 10th and above the 90th centile, respectively. The proportion with a conditional EFW below the 10th and above the 90th centile was 10.2 and 9.4% at the second scan, respectively. For conditional AC, these figures were 10.7 and 10.3%, respectively. <b><i>Conclusion:</i></b> We have produced reference centiles for EFW and AC growth during the third trimester as a useful tool for quantifying growth.</p>