The Centers for Disease Control and Prevention (CDC) and the National Birth Defects Prevention Network have published a new study updating the national prevalence estimates for selected birth defects in the United States from 2004-2006. You can read the abstract here. The findings from this article are summarized below.

About birth defects and this study:

Birth defects occur in about 3% of all live births. They are also a leading cause of infant death. Timely national estimates of the prevalence of birth defects help us:

• Understand the how many people are affected by birth defects in the United States
• Examine birth defect patterns and trends over time
• Determine if prevention programs are working
• Help communities plan for medical, developmental, and educational services

This CDC study used data from 14 birth defects tracking programs to look at the birth prevalence of birth defects in the United States from 2004-2006. Birth prevalence is the number of babies born with birth defects (including stillbirths and elective terminations) compared to the total number of live births in the population. For this study, researchers took into account maternal age (for Trisomy 13, 21, and 18) and maternal race/ethnicity, which allows state and local programs to use these estimates as a point of reference for comparison with future prevalence estimates. The data from these tracking systems were population-based, which means they looked at all babies born with birth defects who live in the tracking regions.

Main findings from this study include:

• Down syndrome was the most common condition in this study. The estimated national prevalence was 14.47 per 10,000 live births. This means that there are about 6,000 diagnoses of Down syndrome each year in the United States.
• About 7,000 babies are born with a cleft palate, cleft lip or both each year in the United States.
• Common truncus, a type of heart defect, was the least common birth defect in this study. The estimated national prevalence was 0.72 per 10,000 live births. This means that there are about 300 cases of common truncus each year in the United States.

Adjusted National Prevalence Estimates and Estimated Number of Cases in the United States, 2004-2006*

Birth Defects	Cases per Births	Estimated Annual Number of Cases	Estimated National Prevalence per 10,000 Live Births
Adjusted for maternal race/ethnicity**
Central nervous system defects
Anencephaly	1 in 4,859	859	2.06
Spina bifida without anencephaly	1 in 2,858	1460	3.50
Encephalocele	1 in 12,235	341	0.82
Eye defects
Anophthalmia/ microphthalmia	1 in 5,349	780	1.87
Cardiovascular defects
Common truncus	1 in 13,876	301	0.72
Transposition of great arteries	1 in 3,333	1252	3.00
Tetralogy of Fallot	1 in 2,518	1657	3.97
Atrioventricular septal defect	1 in 2,122	1966	4.71
Hypoplastic left heart syndrome	1 in 4,344	960	2.30
Orofacial defects
Cleft palate without cleft lip	1 in 1,574	2651	6.35
Cleft lip with and without cleft palate	1 in 940	4437	10.63
Gastrointestinal defects
Esophageal atresia/tracheoesophageal fistula	1 in 4,608	905	2.17
Rectal and large intestinal atresia/stenosis	1 in 2,138	1952	4.68
Musculoskeletal defects
Reduction deformity, upper limbs	1 in 2,869	1454	3.49
Reduction deformity, lower limbs	1 in 5,949	701	1.68
Gastroschisis	1 in 2,229	1871	4.49
Omphalocele	1 in 5,386	775	1.86
Diaphragmatic hernia	1 in 3,836	1088	2.61
Adjusted for maternal age**
Chromosomal anomalies
Trisomy 13	1 in 7,906	528	1.26
Trisomy 21 (Down syndrome)	1 in 691	6037	14.47
Trisomy 18	1 in 3,762	1109	2.66

*The 14 programs included in this table are Arkansas, Arizona, California [8-county Central Valley], Colorado, Georgia [5-county metropolitan Atlanta], Illinois, Iowa, Kentucky, Massachusetts, North Carolina, Oklahoma, Puerto Rico, Texas, and Utah. The number of live births represented by these 14 programs from 2004-2006 was 4,038,506.
**Adjustments are based on United States live birth population, 2004-2006.

More Information

For more information about birth defects, please visit the CDC’s birth defects webpage.

Reference

Parker SE, Mai CT, Canfield MA, Rickard R, Wang Y, Meyer RE, Anderson P, Mason CA, Collins JS, Kirby RS, Correa A; for the National Birth Defects Prevention Network. Updated national birth prevalence estimates for selected birth defects in the United States, 2004-2006. Birth Defects Res A Clin Mol Teratol. 2010 Sep 28. [Epub ahead of print]