Although our results on placental mitochondria of OB/GDM(+) pregnancies comply with previous findings, showing lower mitochondrial copy number compared to NW placentas [9, 69], inclusion criteria of the populations analyzed in these studies were different to ours, also including type 1 and type 2 diabetes mellitus, placentas from vaginal deliveries, and different ethnic groups, thus keeping open the need of further studies investigating the consequences of insulin action on placental mitochondria in GDM pregnancies. This evidence concerns the gene INS and diabetes mellitus.