A series of 4-D scans that appear to show fetuses "grimacing" because their mothers smoked cigarettes puts a face to the effects of tobacco on unborn children

The scans revealed that fetuses whose mothers were smokers showed significantly higher rates of mouth movements than what would be expected, the Durham University reported.

"Technology means we can now see what was previously hidden, revealing how smoking affects the development of the fetus in ways we did not [realize]. This is yet further evidence of the negative effects of smoking in pregnancy," said co-author Professor Brian Francis, of Lancaster University.

The findings suggest maternal smoking has an effect on the fetal nervous system, which controls movements. The nervous system may develop more slowly or in a different way in these fetuses compared with those whose mothers did not smoke. Past studies have shown a delay in speech processing abilities in infants who were exposed to smoking while in the womb.

To make these new findings the researchers looked at 80 4-D ultrasound scans of 20 fetuses taken at four different times between 24 and 36 weeks of gestation. Four of these fetuses belonged to mothers who smoked an average of 14 cigarettes a day, while the other 16 fetuses belonged to non-smoking mothers.

"Our findings concur with others that stress and depression have a significant impact on fetal movements, and need to be controlled for, but additionally these results point to the fact that nicotine exposure per se has an effect on fetal development over and above the effects of stress and depression," said Lead author Dr. Nadja Reissland, in Durham University's Department of Psychology. "A larger study is needed to confirm these results and to investigate specific effects, including the interaction of maternal stress and smoking."

The findings were published in a recent edition of the journal Acta Paediatrica.

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