A major birth defect is an abnormality that can affect the structure or function of an organ. In the United States, major birth defects are the leading cause of infant mortality and contribute substantially to childhood disability and morbidity. Globally, these conditions lead to the death of millions of infants and children annually. Patients with 1 or more affected family members may be at increased risk for having a child with a major birth defect; thus, accurate knowledge of these conditions among family members of their patients gives the clinician the ability to provide improved risk assessment and reproductive planning. Such knowledge can also serve as motivation for patients to adhere to healthy behaviors such as folic acid use or smoking cessation. To evaluate the utility of collecting family history reports of major birth defects as a public health strategy, 6 key criteria were examined by reviewing the relevant published literature. Overall, the review showed that major birth defects satisfied several of the criteria. Additional research is needed, however, regarding the awareness of parent reports of the occurrence of these conditions among relatives and how knowledge of birth defect diagnoses and related risk factors are transmitted among relatives. Such research needs to encompass not only immediate family members but also other first-degree and second-degree relatives. In summary, routine collection of family history reports of birth defects in pediatric practice holds promise as a public health strategy to reduce the burden of morbidity, mortality, and disability associated with major birth defects. 2 To date, gene discovery using such information has accounted for a small proportion of the total burden of a particular disease (eg, BRCA1 mutations for breast cancer prevention). 3 Less well understood is the contribution of a positive family history as a predictor of common chronic diseases that encompass both genetic and partial genetic origins (ie, multifactorial conditions). 4 For the pediatric patient, birth defects exemplify such multifactorial conditions. Birth defects can be grouped into 2 broad categories: major and minor defects. A major defect is an abnormality of an organ structure or function that results in physical disability, mental disability, or death, 5 whereas a minor defect does not produce significant health consequences. 6 Both major and minor defects can occur as isolated entities, affecting 1 organ system, or as multiple defects, affecting 1 or several organ systems. Alone, minor defects are not considered to have significant health consequences, although their presentation with 1 or more major defects can provide clues to an underlying genetic or teratogenic etiology. Conservatively, estimates suggest that a causal gene or teratogen accounts for Ͻ30% of defects that occur. For the remainder, the most likely explanation is a confluence of genetic and teratogenic exposures and, to a lesser degree, factors such as intrauterine constraint and amniotic bands that can l...