search for information spacer
search birth defects
search environmental factors
search geographic areas
birth defects the solution is research discoveries and data serving the public visitor type
home page
discoveries and data center
all birth defects
specific conditions
exposures and risk factors
geographic data

take our survey

Look up in our Glossary

atrioventricular canal
gastrointestinal defects
heart defects
Hirschsprung disease

reference informationReferences

down syndrome - associated birth defects

We tabulated associated birth defects seen in 2894 infants with Down syndrome and found:

bullet Heart defects are the most frequent associated defect, affecting 56% of cases. The most common type is atrioventricular canal/endocardial cushion defects, seen in 17% of cases1000 times more frequently than in babies without Down syndrome.
bullet About 11% have defects of the gastrointestinal tract. Duodenal atresiafound in about 5% is 265 times more common in babies with Down syndrome than in the general population. reference information
bullet There is substantial overlap between heart and gastrointestinal defects. For example, 86% of infants with duodenal atresia also have heart defects. reference information


Serious structural birth defects occur in many but not all infants with Down syndrome. Do environmental factors-interacting with the developmental instability caused by the extra chromosome-influence which babies have associated abnormalities? We interviewed mothers of 687 infants with Down syndrome to answer this question for heart and gastrointestinal defects.

bullet 4.2% of these mothers drank 4 or more cups of coffee daily; they had a 6 times higher chance of having a baby with Hirschsprung disease.
bullet 12% of mothers smoked during the first trimester. Their babies had double the risk for heart defects compared to babies of nonsmokers.
bullet Several factors were not associated with any Down syndrome-associated defect:
- Fever
- Alcohol use
- Mother's age. reference information

Main Down syndrome page

table - birth defects in down syndrome


contact information