This is true of the woman with either preexisting diabetes or gestational diabetes because the increased risk associated with this disease left uncontrolled include both congenital birth defects and fetal death.
One of the most serious problems associated with a diabetic mother is ketoacidosis, which is an increase in the acidity of her blood caused by high blood glucose levels. Fetal death rates are increased by 50% from this complication because the fetal enzyme system can no longer function in a high acid environment.
Another major factor in fetal death rates in diabetic pregnancies is the risk of congenital birth defects. This risk occurs in 5 to 10 percent of all pregnancies in which diabetes is a factor. Medical research has shown that the increased risk of birth defects is brought about by a multitude of factors that include high blood sugar levels during the early part of pregnancy.
The heart, central nervous system, and skeletal system can all be affected in the growing fetus. Septal defects, coarctation of the aorta, and transposition of the great vessels are all fetal heart defects that are at an increased risk for gestational diabetes. The central nervous system can suffer from hydrocephalus, meningomyelocele, and ancephaly. Sacral agenisis is a disorder specific to gestational diabetes in which the lumbar spine and sacrum are unable to develop correctly. This has the effect of severely stunting the development of the lower extremities.
Macrosomia, which is excessive growth and fat storage, is another risk factor for gestational diabetes. Babies born with this condition are overly large for their gestational age but it can be controlled if the mother keeps her blood glucose levels under control. Large amounts of glucose crossing the placenta are the primary cause of this problem in which the fetus produces large volumes of insulin to deal with it. This over supply of insulin causes hyperinsulinism and hyperglycemia which is the primary factor in macrosomic babies. Babies who suffer from this condition are unable to be delivered vaginally because of their large size so a c-section must be done.
The reverse of macrosomia can also occur in a diabetic mother. Intrauterine growth restriction (IUGR) is a condition caused by changes in the mother's vascular system and leads to a gestationally small baby. These vascular changes compromise the blood flow to the fetus, which restricts the amount of nutrients the fetus receives.
High fetal insulin levels also contribute to respiratory distress syndrome in which the enzymes needed for surfactant production are inhibited. Surfactant is a lining that coats the lungs and allows newborns to breathe when they are born.
The last major risk for babies born to diabetic mothers is Polycythemia in which to many red blood cells are being produced. This creates an inability for the mother's blood to release oxygen which affects the fetal liver's ability to metabolize bilirubin that is being synthesized by the over abundance of red blood cells.
The risk factors for babies from gestational diabetes are very high. This is why it is important that all pregnant women be tested for this form of diabetes during their pregnancy.
Women who already have type 1 or 2 diabetes upon getting pregnant will need to follow a strict diet, exercise and medical regimen overseen by their health care team to ensure the normal development of their baby. Gestational diabetes does pose many dangers to the unborn fetus but with proper management and care the outlook is very positive.