LEP and fetal growth restriction: In 2016, Aydin and coworkers [115] investigated leptin levels in maternal and cord serum of IUGR neonates and their mothers and concluded that the maternal leptin levels for the IUGR cohort (16.00 ± 9.80 ng/mL) and the normal group (19.7 ± 16.3 ng/mL) were comparable.