Pancreas

The pancreas is a slender, pink organ, about 8-10 inches in length, lying between the stomach and small intestine. The pancreas is an exocrine organ, supplying digestive enzymes and buffers, and an endocrine organ. The endocrine pancreas consists of islets of Langerhans , which are groups of cells scattered throughout, each containing 4 cells types. One of the cell types are beta cells, which produce insulin. Insulin lowers blood glucose by increasing the rate of glucose uptake and utilization by most body cells.

The growing fetus has heavy needs for glucose, amino acids and lipids. Even during early pregnancy the fetus makes demands on the maternal glucose stores. Ideally, hormonal changes of pregnancy help meet the fetal needs, without putting the mother's metabolism out of balance.

Some of the features of pregnancy, glucose and insulin include:

• In early pregnancy, there is a decrease in maternal glucose levels because of the heavy fetal demand for glucose. The fetus is also drawing amino acids and lipids from the mother, decreasing her ability to synthesize glucose. As a result, maternal glucose concentrations decline to a level that would be considered "hypoglycemic" in a nonpregnant woman. In early pregnancy there is also a decrease in maternal insulin production and insulin levels.

Click here to study more indepth metabolic changes in pregnancy (from World Federation of Societies of Anaesthesiologists)

Look for the answer to this question. What "descriptive" term is used for the state of dramatic carbohydrate change in the pregnant woman?

• The pancreas is responsible for the production of insulin, which facilitates entry of glucose into cells. It's important to remember that though glucose and other nutrients easily cross the placenta to the fetus, insulin DOES NOT. The fetus must produce it's own insulin to facilitate the entry of glucose into it's own cells.
• After the first trimester, HPL from the placenta, and steroids (cortisol) from the adrenal cortex act against insulin.
  • Prolactin, estrogen and progesterone are also thought to oppose insulin
  • As a result, glucose is less likely to enter mother's cells, and is more likely to cross over the placenta to the fetus.

Instant Feedback:

Hypoglycemia in early pregnancy is always abnormal.

TRUE or FALSE

If the mother has normal beta cells of the islets of Langerhans, there is usually no problem meeting the demands for extra insulin. However, if a woman has inadequate numbers of beta cells, she may be unable to produce enough insulin, and will develop diabetes during pregnancy.

In that case, maternal blood sugars rise, necessitating insulin to be administered to women previously not diabetic, or diabetic, but previously diet controlled.

• Uncontrolled diabetes in pregnancy generally produces a large baby (macrosomia). Since the baby is able to produce all the insulin it needs, it takes in the glucose and stores the extra as fat. These babies are often too large to be delivered, except by assisted delivery and/or cesarean section

It is recommended that all women be screened for gestational diabetes in early pregnancy. The most common screening is the 50 gram glucose test. The woman drinks a glucose drink supplying 50 grams of glucose, and her blood sugar is measured an hour later. If her blood sugar is more than 140 mg/dl she gets further screening.

Unless there are risk factors in the woman's history, testing usually occurs around the 24th week. This is when the hormones from the placenta, that are opposing insulin, are at their peak. After delivery of the placenta, opposition to insulin ceases, and glucose and insulin production quickly return to prepregnancy state.

The "Diabetes 123" site is one of the many resources for information on gestational diabetes. Please investigate this link, and be prepared to answer the following question.

When screening for gestational diabetes with a 100 gram, 3 hour glucose tolerance test, how many abnormal values should indicate the need for dietary counseling and repeated testing?

FYI, the NIH has a guide for Gestational Diabetes, that's directed toward toward the consumer.