LEP and gestational diabetes: Interestingly, women with gene polymorphisms on the leptin receptor gene (LEPR) were also more likely to develop severe pre‐eclampsia.7 These results are also consistent with previous studies showing associations between elevated leptin levels during pregnancy and GDM.11, 12, 13 In particular, leptin concentrations in maternal plasma at 13 weeks of gestation were positively associated with GDM risk,11 and two recent systematic reviews showed that maternal leptin concentrations in pregnancy were significantly higher in women with GDM versus controls.12, 13