Diabetes and pregnancy

Women of childbearing age with diabetes are regularly informed of the benefits of preconception glycaemic control and of any risks, including medication that may harm an unborn child. Women with diabetes planning a pregnancy are offered preconception care and those not planning a pregnancy are offered advice on contraception.

What happens waith diabetes and pregnancy?

During pregnancy, the placenta supplies a growing fetus with nutrients and water. The placenta also makes a variety of hormones to maintain the pregnancy. In early pregnancy, hormones can cause increased insulin secretion and decreased glucose produced by the liver, which can lead to hypoglycemia (low blood glucose levels). In later pregnancy, some of these hormones (estrogen, cortisol, and human placental lactogen) can have a blocking effect on insulin, a condition called insulin resistance.

It is very important for a mother to closely manage her diabetes during pregnancy. Generally, the poorer the control of blood glucose and the more severe the disease and complications, the greater the risks for the pregnancy.

Maternal complications of diabetes on a pregnancy 

Complications for the mother depend on the degree of insulin need, the severity of complications associated with diabetes, and control of blood glucose.

Most complications occur in women with pre-gestational diabetes and are more likely when there is poor control of blood glucose. Women may require more frequent insulin injections. They may have very low blood glucose levels, which can be life threatening if untreated, or they may have ketoacidosis, a condition that results from high levels of blood glucose. Ketoacidosis may also be life threatening if untreated. It is not clear whether pregnancy worsens diabetic related blood vessel damage and retinal changes, or if it causes changes in kidney function.

Complications for fetus and baby

Infants of mothers with diabetes are at greater risk for several problems, especially if blood glucose levels are not carefully controlled, including the following:

Birth defects: Birth defects are more likely in infants of diabetic mothers, especially insulin-dependent women who may have two to six times greater the risk of major birth defects. Some birth defects are serious enough to cause fetal death. Birth defects usually originate sometime during the first trimester of pregnancy. They are more likely in women with pre-gestational diabetes, who may have changes in blood glucose during that time. Overall, major birth defects may occur in about 5 to 10 percent of infants born to insulin-dependent women. Major birth defects that may occur in infants of diabetic mothers include the following:

Heart and connecting blood vessels

Brain and spine abnormalities

Urinary and kidney

Digestive tract

Stillbirth (fetal death): Stillbirth is more likely in pregnant women with diabetes. The fetus may grow slowly in the uterus due to poor circulation or other conditions, such as high blood pressure or microvascular disease, which can complicate diabetic pregnancy. The exact reason stillbirths occur with diabetes is unknown. The risk of stillbirth increases in women with poor blood glucose control and with blood vessel changes.

Macrosomia: Macrosomia refers to a baby that is considerably larger than normal. All of the nutrients the fetus receives come directly from the mother's blood. If the maternal blood has too much glucose, the pancreas of the fetus senses the high glucose levels and produces more insulin in an attempt to use this glucose. The fetus converts the extra glucose to fat. Even when the mother has gestational diabetes, the fetus is able to produce all the insulin it needs. The combination of high blood glucose levels from the mother and high insulin levels in the fetus results in large deposits of fat that causes the fetus to grow excessively large.

Managing diabetes during the pregnancy?

Special fetal testing and monitoring may be needed for pregnant diabetics, especially those who are taking insulin (because of the increased risks for stillbirth). These tests can include the following:

Fetal movement counting: Counting the number of movements or kicks in a certain period of time, and watching for a change in activity.

Ultrasound: A diagnostic imaging technique which uses high-frequency sound waves and a computer to create images of blood vessels, tissues, and organs. Ultrasounds are used to view internal organs as they function, and to assess blood flow through various vessels.

Non stress testing:A measurement of the fetal heart rate in response to the fetus' movements.

Biophysical profile: A test that uses the nonstress test and ultrasound to examine fetal movements, heart rate, and amniotic fluid amounts.

Doppler flow studies: A type of ultrasound which uses sound waves to measure blood flow.