Statistical analysis
Statistical analysis was performed using STATA 15 (StataCorp., College Station, TX, USA). Categorical data were compared usingX2 test or Fischer exact as appropriate and was presented as number (%). For continuous variables distribution of the data was judged by the Skewness and Kurtosis test. Wilcoxon rank sum test was used for statistical analysis when the data was not normally distributed; the continuous variables are presented as median and interquartile ranges.
The risk ratios (RR) and 95% CI were estimated using the non SGA group as the reference group. Sensitivity, specificity, and positive and negative predictive values for the primary and secondary outcomes using these fetal weight standards were calculated. The discriminatory ability of each fetal growth chart was compared using area under receiver operating characteristic curves (AUC). A p value < .05 was consider significant.