Denise Grady | The New York Times | 17 November 2008
Infants conceived with techniques commonly used in fertility clinics are two to four times more likely to have certain birth defects than are infants conceived naturally, a new study has found.
The findings applied to single births only, not to twins or other multiples. The defects included heart problems, cleft lip, cleft palate and abnormalities in the esophagus or rectum. But those conditions are rare to begin with, generally occurring no more than once in 700 births, so the overall risk was still low, even after the fertility treatments. Cleft lip, for instance, typically occurs in 1 in 950 births in the United States, and the study found that the risk about doubled, to approximately 1 in 425, among infants conceived with the fertility treatments.