The actual table, and what it does not contain
Thirty-three conditions with real numbers. It is a list, not a catalogue of everything that can happen.
Almost every article about birth defects gives you one number and stops. Here is the table underneath the number.
These are the most recent national figures, from eleven surveillance programmes covering 4,231,701 births between 2018 and 2022, about 23 in every 100 American births in that period. Each of these programmes goes through medical records by hand rather than waiting for a form to be filed, which finds more cases than the alternative.
| Condition | Per 10,000 births | About | US babies a year |
|---|---|---|---|
| Clubfoot | 17.6 | 1 in 568 | 6,507 |
| Down syndrome (trisomy 21) | 16.1 | 1 in 621 | 5,952 |
| Pulmonary valve atresia and stenosis | 11.3 | 1 in 885 | 4,178 |
| Cleft lip with cleft palate | 6.5 | 1 in 1,538 | 2,403 |
| Cleft palate alone | 6.4 | 1 in 1,563 | 2,366 |
| Atrioventricular septal defect | 6.3 | 1 in 1,587 | 2,329 |
| Coarctation of the aorta | 5.8 | 1 in 1,724 | 2,144 |
| Limb reduction defects | 5.4 | 1 in 1,852 | 1,996 |
| Tetralogy of Fallot | 4.9 | 1 in 2,041 | 1,812 |
| Rectal and large intestinal atresia or stenosis | 4.8 | 1 in 2,083 | 1,775 |
| Gastroschisis | 3.9 | 1 in 2,564 | 1,442 |
| Spina bifida without anencephaly | 3.5 | 1 in 2,857 | 1,294 |
| Cleft lip alone | 3.4 | 1 in 2,941 | 1,257 |
| Diaphragmatic hernia | 3.3 | 1 in 3,030 | 1,220 |
| Trisomy 18 | 3.2 | 1 in 3,125 | 1,183 |
| Transposition of the great arteries | 3.1 | 1 in 3,226 | 1,146 |
| Omphalocele | 2.7 | 1 in 3,704 | 998 |
| Double outlet right ventricle | 2.6 | 1 in 3,846 | 961 |
| Hypoplastic left heart syndrome | 2.6 | 1 in 3,846 | 961 |
| Esophageal atresia and tracheoesophageal fistula | 2.4 | 1 in 4,167 | 887 |
| Anencephaly | 2.1 | 1 in 4,762 | 776 |
| Anophthalmia and microphthalmia | 2.1 | 1 in 4,762 | 776 |
| Tricuspid valve atresia and stenosis | 1.8 | 1 in 5,556 | 665 |
| Trisomy 13 | 1.5 | 1 in 6,667 | 555 |
| Total anomalous pulmonary venous connection | 1.5 | 1 in 6,667 | 555 |
| Encephalocele | 1.1 | 1 in 9,091 | 407 |
| Interrupted aortic arch | 1.1 | 1 in 9,091 | 407 |
| Ebstein anomaly | 0.8 | 1 in 12,500 | 296 |
| Common truncus | 0.7 | 1 in 14,286 | 259 |
| Single ventricle | 0.7 | 1 in 14,286 | 259 |
One thing the table cannot tell you is why. A study of every major birth defect in Utah over five years, 5,504 of them in 270,878 births, could assign a definite cause to only one in five. For the other four in five there was no identifiable cause at all, which is worth knowing before you go looking for something you did.
Three narrower categories sit inside three of those rows and are left out of the table above so that nothing is counted twice: pulmonary valve atresia on its own (1.2 per 10,000), tricuspid valve atresia on its own (0.8), and dextro-transposition of the great arteries (2.6).
3 to 5%of US births. The CDC statistics page it is linked from says 1 in 33, which is 3.0%. These are different claims and there is no way to hold both at once. The 1 in 33 figure is the better one to use, because it can be traced to a named surveillance system, but it should be described as CDC's estimate rather than as a measured national rate.
"Is the number you are quoting me from before or after pregnancies that ended early were taken out?"
"Is this from a programme that checks records by hand, or one that waits for reports?"