Many women have difficulty maintaining normal blood sugar levels during pregnancy and now new research suggests that this problem may raise their long-term risk of cancer, especially breast cancer. Previous reports have suggested a link between diabetes and cancer risk, study author Dr. Shelagh I. Dawson, from the University of Otago in Christchurch, New Zealand, notes. However, it was unclear if other forms of disease, such as mild sugar problems during pregnancy, were also associated with an elevated risk of cancer. To investigate, Dawson assessed the 20-year cancer outcomes of 753 women who were enrolled in a study looking at the effect of a mother's sugar levels on the developing baby. Various data were analyzed to determine if any of the subjects were admitted to the hospital with a cancer diagnosis during the study period. The researchers' findings are reported in the medical journal Cancer. Thirty-four women--4.5 percent of the entire group--were diagnosed with cancer and in 18 cases this was a breast cancer, Dawson notes. The more impaired women were in controlling sugar levels during pregnancy, the greater their risk of cancer, the findings indicate. In fact, women with the worst control were up to 5- and 11-times more likely to develop any cancer and breast cancer, respectively, than women with the best control. "These results are in keeping with studies that suggest that many (cancers) are associated with altered (sugar) metabolism," Dawson states. However, as far as she knows, no study published to date has "examined a continuum of risk across the full spectrum of (sugar) tolerance."