There is no known prevention for hypoplastic left heart syndrome. As with many congenital diseases, the causes of hypoplastic left heart syndrome are uncertain and have not been linked to a mother's disease or behavior.
Zipes DP, Libby P, Bonow RO, Braunwald E, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine, 8th ed. St. Louis, Mo; WB Saunders; 2007.