Diabetes mellitus

Disease in which the body is no longer able to regulate blood sugar levels because the pancreas has stopped producing insulin or the body's cells are not able to use efficiently the insulin that is produced. There are two types of diabetes in pregnancy: 1) pre-existing diabetes (present before conception) and 2) gestational diabetes (develops during pregnancy). During pregnancy, women with pre-existing diabetes may need to take more insulin. Women with gestational diabetes must alter their diet and may also need insulin shots to keep their blood sugar levels under control.

Diabetes in pregnancy is categorized according to how severe it is, what complications are present, and how long the woman has had diabetes before she became pregnant. Infants born to women with pre-existing diabetes are at increased risk for birth defects of the heart, intestine, and sacrum. Controlling blood sugar levels at the time of conception and for the first months of pregnancy when the organs are forming reduces the risk of birth defects.

Control of the blood sugar in later stages of pregnancy is important to prevent the baby from becoming excessively large. Babies whose mothers have high blood sugar levels are constantly 'fed' a large amount of glucose through the placenta. The baby tries to accelerate growth fast enough to deal with the extra glucose. This results in excess fat deposition and growth. After birth, when the unusually large supply of glucose is stopped after delivery, the baby may develop a low blood sugar. The high insulin levels in the baby, which develop in response to the mother's high glucose level, are no longer counteracted by the sugar coming across the placenta. A dangerously low blood sugar level can develop.

Other problems may also occur in infants whose mothers have diabetes. These infants may have a difficult delivery because they are too large to fit easily through the birth canal. Diabetes mellitus in the mother has also been associated with delayed lung development in the infant. This means that if an infant is born prematurely to a woman with diabetes, there is an increased chance that the baby will have immature lungs and will require help in breathing for the first few days or weeks.

Most women with diabetes have successful pregnancies and healthy infants; however, they need to manage their diet, insulin and blood sugar very carefully.