Statistical analysis.
Participants’ baseline characteristics were summarised using means,
medians, standard deviations, and interquartile ranges for continuous
variables where applicable. Categorical data were summarized using
numbers and proportions. We used Pearson’s chi-square and Fisher’s exact
tests to assess the associations between GDM and maternal and neonatal
outcomes, and present crude odds ratios (ORs).
Participants with DIP were excluded from the multivariate analysis.
Univariable and multivariable logistic regression was used to
investigate the effect of GDM, as a categorical variable, and OGTT blood
glucose concentrations as continuous variables, for each of the primary
and secondary outcomes. These were adjusted for potential confounders
i.e. study site, mid-gestational BMI, maternal height, maternal age,
parity, mean arterial pressure, HIV status, and previous macrosomia.
These final adjust models are presented as odds ratios and their 95%
confidence interval, as per the HAPO Study.3
For continuous variable analysis, odds ratios were calculated for every
1-SD increase in the fasting, 1-hour and 2-hour plasma glucose
concentrations, as per the HAPO study.3 All analyses
were conducted in STATA 15.1 (College Station, Texas).