In the largest study ever conducted on the effects of smoking and incidence of birth defects, it has now been found that maternal smoking is associated with an increased risk of finger and toe abnormalities. The birth defects could range from polydactly (presence of extra digits in either the arms or feet) to webbed (syndactyly) or missing toes and fingers (adactyly).
The researchers studied data related to more than 6.8 million live births (2001-2002) in the United States. The incidence of toe and finger abnormality in this group was as high as 5,171 even when other factors such as cardiovascular disease, diabetes and hypertension were absent in the study group.Alarmingly, it has been found that smoking 1- 10 cigarettes a day increases the risk of finger or toe abnormality by as much as 29%. The risk was found to be much higher when this figure increased to more than 10 or 20 with 38 and 78% respectively. The results of this study appear in the journal of Plastic and Reconstructive Surgery.
The incidence of syndactyly is approximately 1 in 2000 to 2500 live births and is particularly high among the Caucasian population. Polydactyly is however more common, with an incidence of 1 in 600 and is more common among individuals of an African American descent. These defects are multifactorial, and caused by a combination of genetic and environmental factors. Therefore, identification of a definitive environmental factor is of crucial importance in the prevention of such birth defects.
“Reconstructive surgery to repair limb, toe and finger abnormalities in children represents a large portion of my practice - it is the most common issue I treat. Parents would ask why this happened to their child, but I didn't have an answer. This study shows that even minimal smoking during pregnancy can significantly increase the risk of having a child with various toe and finger defects," said Benjamin Chang, one of the study authors.
"The results of this study were interesting. We suspected that smoking was a cause of digital anomalies but didn't expect the results to be so dramatic. Smoking is so addictive that pregnant women often can't stop the habit, no matter what the consequences. Our hope is this study will show expectant mothers another danger of lighting up", concluded Dr. Chang.
