Babies with congenital hypothyroidism do not have enough of the hormone thyroxine. Without this hormone, they do not grow properly and can develop a serious, permanent, physical and mental disability.
Approximately 18 babies in Wales are born with CHT each year.
Newborn bloodspot screening means that babies with CHT can be identified and treated early with thyroxine tablets. This treatment will prevent serious disability and allow the baby to develop normally. If babies are not screened and are later found to have CHT, it may be too late to prevent them becoming seriously disabled.