Statistical analysis
One-way ANOVA was used for group comparison of continuous variables and
Fisher’s exact test for frequencies. Pearson’s correlation coefficients
(r) were calculated. Multiple Linear Regression was used for identifying
relation between the independent and dependent variables. Binary
logistic regression was used to measure the association between
continuous vitamin D levels and the probability of having diabetes,
preterm delivery, preterm rupture of membranes and 5-minute Apgar score
(AS) <7 and is presented with odds ratios (OR and the 95%
confidence interval). Descriptive statistics were presented as mean with
standard derivation (SD) and medians with interquartile range (IQR). All
tests were two-tailed and a P-value <0.05 was considered
statistically significant. Analyses by IBM SPSS 28 (SPSS Inc. Chicago,
Illinois, USA).