Diabetes mellitus is a broad public health problem, which in the last few decades, with an emphasis on the 21st century, is gaining more and more importance. In the past, it has already been noticed that pregnant women suffering from diabetes give birth to macrosomic children. Those are children who weigh more than 4 kg at birth. In addition to this fact, which makes childbirth more difficult and increases the risk of adverse pregnancy outcomes, there are also many complications, both for the mother and the child, that can develop as a consequence of diabetes. Pregnant women, for example, have an increased risk of developing preeclampsia, hypertension and diabetes mellitus type 2 later in life, while newborns can suffer from hyperinsulinemia with consequent neonatal hypoglycemia and RDS. Therefore, the importance of preventive laboratory determinations of blood glucose in pregnant women and keeping these values low enough, first by changing the lifestyle, and then by pharmacological therapy, is recognized.