Rasmussen and Kjolhede [44] suggested a negative relationship between maternal obesity and suckling-related prolactin secretion during the first week in humans, delaying the first 24 h of spontaneous prolactin release (without any relationship with the progesterone concentration) and the onset of the milk breastfeeding, without considering the adverse effects on the fetal viability. The gene discussed is PRL; the disease is obesity due to melanocortin 4 receptor deficiency.