Doctors are constantly reminding pregnant women of the risk factors associated with smoking during pregnancy. These risk factors include lower birth weight and increased risk of miscarriage, but despite the warnings, there have been no proven physical birth defects associated with smoking, until now.
According to a new study at University College London, infants born to women who smoke during pregnancy are at increased risk of missing limbs, deformed limbs, clubfoot, gastrointestinal defects, skull defects, eye defects and cleft palate or lip. Risk of gastroschisis, a physical condition where the intestines escape through a hole in the stomach, increases 50-percent for women who smoke.
Researchers sorted through more than 170 papers published over a 50 year time span. More than 170,000 cases of birth defects were compared to 11 million control births. The resulting connection between smoking and birth defects was clear. Increased risks of physical birth defects were reported as follows:
- Missing or deformed limb – 26%
- Clubfoot – 28%
- Gastrointestinal Defects – 27%
- Skull Defects – 33%
- Eye Defects – 25%
- Cleft Lip/Palate – 28%
- Gastroschisis – 50%
*There is a chance that risk factors are even higher because some women do no admit to smoking during pregnancy.
Researchers are hoping this new information will be used to educate pregnant women on the physical risk factors of smoking during pregnancy. Anti-smoking campaigns have been met with lax results in the past. In the United Kingdom, 45-percent of pregnant women under the age of 25 smoke. In the United States, 20-percent of pregnant women under the age of 25 smoke. While the number of pregnant woman who smoke during pregnancy tends to decrease with age, there are still plenty of women who smoke while pregnant throughout the late 20s, 30s and 40s.
According to Charles Rodeck from the UCL Institute for Women’s Health, “The results of this research are of the greatest significance for the health of mothers and babies and for public health policy. If the recommendations are implemented, they will lead to a reduction in the incidence of several common malformations, and also to greater efficacy of smoking prevention program[s], as the warning of a birth defect adds weight to that of a small or premature baby.”
Source: Human Reproduction Update. Allan Hackshaw, Charles Rodeck, Sadie Boniface. 12 July, 2011.