Statistical analysis
abortion
REGRESSION, CHRONIC DISEASES, INTRAUTERINE GROWTH RESTRICTION
Statistical analysis of data and comparison of groups was done using one-way analysis of variance (ANOVA) for quantitative variables such as maternal age and body mass index (BMI), number of previous births, number of steroid injections, infant birth weight, height, head circumference, gestational age at birth based on ultrasound and age upon entry to the study, frequency of liquids consumed based on the number of glasses per day, frequency of pump usage, time spent on the pump, time spent skin-to-skin with the infant, number of infant serum injections, amount of milk pumped at the end of each day and the weight of infants on the first (before intervention), third, fifth and seventh days after participating in the study. Fisher's exact test was used for variables relating to paternal occupation and the reason for the infant's admission to the hospital. The Chi-Square test was used for qualitative variables such as educational levels, maternal occupation, whether the pregnancy was planned, mode of birth, abortion history, chronic diseases, drug use during pregnancy, maternal use of iron and complementary drugs, the socio-economic status of the family and the infant’s sex assigned at birth, the consumption of foods with milk-increasing properties and type of infant serum injections.The significance of variables such as the mode of birth, the infant's birth weight, the infant's height, intrauterine growth restriction, the type and number of infant serum injections was calculated. Yet in order to adjust these variables from covariance analysis for frequency of pump usage, time spent on pump, time spent skin-to-skin with the infant, the number of infant serum injections, the amount of milk pumped at the end of each day and the weight of infants on the first (before the intervention), third, fifth and seventh day shortly after the study intervention period, the logistic regression model was used.Analysis of variance with repeated measures was used to compare the amount of human milk pumped at the end of each day and the weight of infants on the first (before the intervention), third, fifth and seventh days shortly after the intervention period of the study. The data were analyzed using SPSS software version 23 (IBM Corp, US). The significance level of the tests was considered to be < 0.05. The eta square index was considered to measure the effect size.