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.