What causes hypoplastic left heart syndrome and how common is it?
During the first eight weeks of a pregnancy, while a child’s organs are developing, certain types of problems can happen during the development of a baby’s heart. Hypoplastic left heart syndrome (HLHS) is the name of one set of problems that can impact a child’s heart and connecting blood vessels. The reasons that some babies develop HLHS are not known. This type of birth defect may not be linked to anything that a mother did either before or during her pregnancy. It has been found that many heart defects may be caused by a problem with the genes that the baby receives from his or her mother or father. Mothers or fathers who have had a baby with HLHS may receive advice to get testing and information from a genetic counselor to help them understand if they are at risk of having another baby with a heart defect. About one out of every 3,700 babies who are born alive in Florida will have HLHS. Baby boys have a 38% more likely than baby girls to be born with this heart defect. What is hypo
