Statistical analysis
Shapiro-Wilk-Test was used to determine whether continuous variables were normally distributed. Obese women were compared for categorical variables with underweight, normal weight and overweight women using Pearson’s χ2 test or Craddock’s Flood χ2 test. The same tests were used for the analysis of the obesity groups. A mixed effects Cox regression model was used to determine the impact of maternal BMI on the length of stay in the NICU between the weight categories.
All analyses were completed using BiAS. (Version 11.12, epsilon Verlag, Frankfurt, Germany) and RStudio (Version 4.1.1, RStudio Team (2020). RStudio: Integrated Development for R. RStudio, PBC, Boston, MA, USA). A Bonferroni correction was used to adjust p values. Therefore, ap value <0.003 was considered significant for maternal outcomes and <0.005 for neonatal outcomes. Odds ratios and relative risks were calculated with a 95% confidence interval.