• Table 1

    Leading Categories of Birth Defects

    Leading causes of birth defects.The estimated incidences for the leading categories of birth defects are provided in the table below. Birth defects are grouped into three major categories:

    1. structural/metabolic;
    2. congenital infections; and
    3. other conditions.

    Birth defects of the heart and circulatory system affect more infants than any other type of birth defect. Of all infants born each year, approximately 1 in 115 has heart and/or circulatory defects.

    Birth DefectsEstimated Incidence
    Structural / Metabolic
    Heart and circulation1 in 115 births
    Muscles and skeleton1 in 130 births
    Club foot1 in 735 births
    Cleft lip / palate1 in 930 births
    Genital and urinary tract1 in 135 births
    Nervous system and eye1 in 235 births
    Anencephaly1 in 8,000 births
    Spina bifida1 in 2,000 births
    Chromosomal syndromes1 in 600 births
    Down syndrome (Trisomy 21)1 in 900 births
    Respiratory tract1 in 900 births
    Metabolic disorders1 in 3,500 births
    PKU1 in 12,000 births
    Other
    Rh disease1 in 1,400 births
    Fetal alcohol syndrome1 in 1,000 births

    Sources: March of Dimes Perinatal Data Center, 2000. Unpublished review of the literature and information from various state and regional, birth defects surveillance systems (California, Iowa, Metropolitan Atlanta, New York, and Texas).