TNF and obesity due to melanocortin 4 receptor deficiency: To determine if pre-pregnancy obesity is linked to the altered Flt3L, IL-6 and TNFα concentrations in pregnancies affected by preterm birth, we compared abundance levels of Flt3L, IL-6 and TNFα in maternal plasma samples of women without obesity (Term; n = 30, Preterm; n = 25) and women with obesity (Term; n = 8, Preterm; n = 9) prior to birth (Fig. 2).