A study found that breast cancer risk was 30% lower in women who developed temporary diabetes during pregnancy than in women who didn't develop diabetes while pregnant. About 4% of pregnant women develop this type of diabetes, known as gestational diabetes. If a woman has gestational diabetes, she develops abnormally high blood sugar levels during her pregnancy. Her blood sugar levels return to normal after she gives birth.
Besides appearing to reduce breast cancer risk, having diabetes during pregnancy can cause problems for both mothers and babies. Newborns whose moms developed gestational diabetes can be overweight at birth and may have temporary blood sugar problems right after being born. Women who develop gestational diabetes are more likely to develop type I or type II diabetes later in life. Their children also face a higher risk of developing diabetes as adults.
Doctors aren't sure why gestational diabetes appears to lower breast cancer risk. But studying the link might provide a better understanding of how breast cancer happens and suggest new approaches to treatment. Stay tuned to breastcancer.org for the latest information on breast cancer research.