Statistical analysis
Participants were stratified based on the presence of uterine myoma; clinical and demographic sample characteristics were reported accordingly. The Student’s t-test was used to compare characteristics expressed as continuous variables between each group, and the chi-square test was used to compare characteristics expressed as categorical variables. First, adjusted odds ratios (aORs), and 95% confidence intervals (CIs) for PTB, pPROM, II, and GH were calculated using a multiple logistic regression model with the control group as reference. Second, the effect of II on the incidence of PTB, and pPROM in women with, and without uterine myomas was evaluated using a multiple logistic regression model with women without II used as reference. All ORs were adjusted for maternal age, maternal BMI before pregnancy, parity, maternal smoking status, maternal educational status, and annual household income.
SPSS version 26 (IBM Corp., Armonk, NY, USA) was used for statistical analysis. A p-value < 0.05 indicated statistical significance.