The finding that, in the adjusted model, IL-6 was no longer significantly (P = 0.09) related to IH can easily be explained by the important confounding effect of obesity on inflammation; at 12 weeks gestation, obese women were 3.5 times more likely to have high IL-6 levels (OR: 3.49, 95% CI: 2.3–5.2, P < 0.001) attenuating the independent effect of IL-6 on IH. This evidence concerns the gene IL6 and isolated hemihyperplasia.