Hi, thank you for query. Between 2 and 7 percent of women develop gestational diabetes during pregnancy, which according to BabyCenter.com makes it one of the most common health complications during pregnancy. Doctors diagnose gestational diabetes between weeks 24 and 28 of pregnancy via a series of tests that detect high glucose levels. While researchers don t know for certain why women develop high blood sugar during pregnancy, there are many credible clues about causes and risk factors supported by the medical community. Getting tested and following medical advice to manage gestational diabetes is important to ensure both mother and baby remain healthy. Pregnancy hormones secreted by the placenta help the baby develop, but also hamper the mother s ability to use the insulin she produces. As a result, the pancreas produces more in an effort to ensure the body is receiving enough to support it and the pregnancy. Gestational diabetes occurs when a woman s pancreas cannot keep up with the insulin demand, according to the American Diabetes Association, and blood glucose levels begin to rise. The link was stronger amongst women who were obese prior to the start of their pregnancies, despite the fact that this group gained the least amount of weight during the first trimester. The study s authors theorized that weight gain early in pregnancy might increase insulin resistance while wearing out the beta cells in the pancreas that create and control insulin. There are several factors, according to the National Diabetes Information Clearinghouse, which can increase a woman s chances for developing gestational diabetes.