Statistical analyses
Participant characteristics were summarized according to the maternal
sleeping status. All variables were found to follow a normal
distribution based on the Shapiro-Wilk test. One-way analysis of
variance was used to compare continuous variables among different MSD
groups, and the chi-square test was used to compare categorical
variables.
Initially, adjusted odds ratios (aORs) and 95% confidence intervals
(CIs) for LBW <2,500 g, LBW <1,500 g, SGA, and
macrosomia were calculated using a multiple logistic regression model,
with women in G2 as the reference. In Model 1, aOR for LBW was adjusted
for maternal age, BMI before pregnancy, parity, maternal smoking status,
maternal alcohol consumption status, maternal educational status, annual
household income, and PTB before 37 weeks. aOR for SGA was adjusted for
maternal age, BMI before pregnancy, maternal smoking status, maternal
alcohol consumption status, maternal educational status, and annual
household income. aOR for macrosomia was adjusted for maternal age, BMI
before pregnancy, parity, maternal smoking status, maternal alcohol
consumption status, maternal educational status, and annual household
income. In Model 2, excessive gestational BWG was added as a confounding
factor (in addition to those of Model 1) to calculate aORs for these
outcomes.
Further, we stratified the participants on the basis of gestational BWG,
and aORs for LBW <2,500 g and SGA were calculated using a
multiple logistic regression model, with women in G2 as the reference,
using the comparable confounding factors in Model 1.
SPSS version 26 (IBM Corp., Armonk, NY, USA) was used for statistical
analyses. Differences with p-values <0.05 were considered
statistically significant.