Wilson's disease is a rare genetic disease, affecting less than 1,500 people in France. The transmission is autosomal recessive linked to an anomaly of the ATP7B gene on chromosome.This gene codes for an ATPase-type transmembrane protein involved in the transport of copper through the cell plasma member.This gene codes for an ATPase-type transmembrane protein involved in the transport of copper through the cell plasma member. If there is no mutation, this ATPase incorporates copper into apo-ceruloplasmin to be released into the blood serum. The mutation of the ATP7B gene results in a defective biliary excretion of copper, leading to its accumulation in the liver, but also in other organs such as the eye or the brain. Advances in treatment have dramatically changed the prognosis for Wilson's disease, making the desire for pregnancy more confident. The consensus is to maintain treatment during pregnancy, reducing the dosage to limit teratogenicity as well as the risk of fetal copper deficiency.The mammary gland is the primary site of copper metabolism in lactation, and ATPase 7B is the primary effector. It has been shown in a mouse model of Wilson's disease (ATP7B - / - mouse) with treatment, that mothers accumulate copper in the liver but also in the mammary gland. However, a recent study showed that the copper level in breast milk was normal in 18 Wilsonian patients treated with D-penicillamine, trientine salts or zinc salts, suggesting that breastfeeding is possible in these patients without risk to the development of the infants.The problem of breastfeeding newborns for patients with Wilson's disease is therefore associated with a risk of copper deficiency in the newborn due to insufficiently rich breast milk in copper due to drugs. In addition, the passage into breast milk of treatments is not sufficiently known. These factors make breastfeeding not currently recommended for Wilsonian mothers,However, many patients wish to breastfeed and some of them breastfeed their newborns despite the risk of breastfeeding