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article_snippet: Although the study involved a small sample of ethnic minority children in poor inner city areas with low educational achievements, a larger study is underway.
article_snippet: As part of the study, Dr Nadja Reissland, of Durham University, used 4-D ultrasound scan images to record thousands of tiny movements in the womb.
article_snippet: She monitored 20 mothers attending the James Cook University Hospital in Middlesbrough, four of whom smoked an average of 14 cigarettes a day.
article_snippet: Dr Reissland said: 'A larger study is needed to confirm these results and to investigate specific effects, including the interaction of maternal stress and smoking.'