Lactation of suckling by the baby. The milk ejection reflex (also called let-down reflex) is not always consistent, especially at first. Once a woman is conditioned to nursing, let-down can be triggered by a variety of stimuli, including the sound of any baby. Even thinking about breastfeeding can stimulate this reflex, causing unwanted leakage, or both breasts may give out milk when an infant is feeding from one breast. However, this and other problems often settle after two weeks of feeding. Stress or anxiety can cause difficulties with breastfeeding. The release of the hormone oxytocin leads to the "milk ejection" or
KCNE2 less milk (hypothyroidism of the dams impairs milk ejection), the milk they receive is deficient in T, and they themselves cannot adequately transport iodide into the thyroid. "Kcne2"-/- pups exhibit stunted growth, alopecia, cardiomegaly and reduced cardiac ejection fraction, all of which are alleviated by thyroid hormone supplementation of pups or dams. Surrogating "Kcne2"-/- pups with "Kcne2"+/+ dams also alleviates these phenotypes, highlighting the influence of maternal genotype in this case. As observed for hERG mutations, KCNE2 loss-of-function mutations are associated with inherited LQTS, and hERG-KCNE2 channels carrying the mutations show reduced activity compared to wild-type channels. In addition, some