TFF2 and gestational diabetes: The SP-D (T/T) genotype existed in 11.6% and 21.6% of GDM patients and matched healthy controls, respectively (odds ratio, 0.473; 95% confidence interval, 0.235–0.952; P = 0.033), indicating that women with the (T/T) genotype had a lower prevalence of GDM (OR = 0.473).