Statistical Analysis
Data obtained in the study were analysed statistically using SPSS vn. 25.0 software (SPSS Inc., Chicago, IL, USA). Continuous variables with normal distribution (p>0.05 in Kolmogorov-Smirnov test or Shapiro-Wilk [n<30]), were reported as mean±standard deviation (SD) values, and those not showing normal distribution were stated as median values. Comparisons between groups were made using the Student’s t-test or the One-way ANOVA test for normally distributed data, and the Mann Whitney U-test or Kruskal Wallis test were used for the data not normally distrubited. Since analysis of variance was significant, comparisons were applied using the Post Hoc test and the Mann Whitney U-test.
Categorical variables were analyzed between the groups using the Chi square test. Multiple linear regression analysis was applied to determine associations between birthweight, gestational age at birth and other measurements, with birthweight or gestational age at birth as dependent variables. Correlations between variables were tested with Spearson’s correlation coefficient. Correlation coefficients were interpreted as either an excellent relationship r ≥ 0.91; good 0.90 ≥ r ≥0.71; fair 0.70 ≥ r ≥ 0.51; weak 0.50 ≥ r ≥ 0.31; little or none r ≤ 0.3.