Negative correlations were found between blood plasma and milk ghrelin in the control rat dams on the 21st day of lactation (r = −0.737, p = 0.029) and between body weight and the plasma ghrelin concentration on the 14th day of pregnancy in the HF rat dams (r = −0.903, p = 0.048). The gene discussed is GHRL; the disease is hydrops fetalis.