Midwifery: Diseases/Conditions

Diabetes in Pregnancy

REFERENCE: Book of Dr. Jose Fabella Memorial Hospital, School of Midwifery

Chronic hereditary disease characterized by hyperglycemia due to a relative insufficiency or lack of insulin produced by the pancreas which, therefore, leads to abnormalities in the metabolism of carbohydrates, proteins and fats.

1. Diabetogenic effects of pregnancy

       Many women who had no evidence of diabetes in the past develop abnormalities similar to diabetes:

     A. Decreased renal threshold for sugar because of increased estrogen; that is why it is not uncommon to find dextrose and lactose in the urine of pregnant women.

     B. Rate of insulin secretion is incresed BUT the sensitivity of the body to insulin is decreased, i.e., insulin does not seem normally effective during pregnancy.

     C. Increased production of adrenocorticoids, anterior pituitary hormones and thyroxine, which affect carbohydrate and lipoid metabolism, thus increasing concentration of glucose in the serum.

2. Risks

      Diabetic gravidas are more prone to:

     A. Toxemia

     B. Infection

     C. Hemorrhage

     D. Polyhydramnios

     E. Spontaneous abortion

     F. Acidosis

     G. Dystocia

3. Diagnosis

      Is made on the basis of the Glucose Tolerance Test:

     A. NPO after midnight

     B. 2ml of 50% glucose/3kg of pre-pregnant body weight is given IV (oral tablet is not advisable because of known decreased gastric motility and delayed absorption of sugar)

     C. Results

In normal person: serum glucose concentration should not exceed 110 mg per 100 ml of blood 2 hours following a glucose meal.

In pregnancy:

•If less than 100mg % - normal

•If 100-120 mg % - possible gestational diabetes

•If more than 120 mg % - overt diabetes

4. Categories

      Predict outcome of pregnancy:

     A. Class A - GTT is only slightly abnormal; minimal dietary restriction; insulin not needed; fetal survival is high.

     B. Classes C to E - have 25% perinatal mortality

     C. Class F - therapeutic abortion may be justified

5. Management

     A. Diet - highly individualized - adequate glucose intake is necessary - (1800-2200) cal.

     B. Insulin requirements - are unpredictable, requiring close observation throughout pregnancy. They reflect the availability of circulating carbohydrates and the antagonistic effects of placental hormones toward insulin. Since the effects of the hormones are more pronounced during the second half of pregnancy, the insulin requirements during the 2nd and 3rd trimesters are, therefore, greater.

•Insulin is regulated to keep urine always +1 for sugar (minimal glycosuria is necessary to prevent acidosis) and negative for acetone.

*Long-lasting insulin (Ultralente) is changed to regular insulin (lente) during the last few weeks of pregnancy.

     C. Diagnostic procedures done to prevent fetal loss from placental insufficiency:

• Placental function tests - e.g., OCT and urinary estriol determination

•Amniocentesis - for determination of fetal maturity

     D. May be delivered by CS if baby is too large or already in distress because of placental insufficiency. Severe metabolic imbalances in vaginal delivery result from depletion of glycogen reserve in the liver and skeletal muscles because of strenuous muscular exertion.

     E. Maximum difficulty in controlling diabetes is during the early postpartum period.

6. Infant of the diabetic mother (IDM)

     A. Is typically longer and weighs more because of :

•Excessive supply of glucose from the mother

•Increased production of growth hormone from the maternal pituitary

•Increased secretion of insulin from fetal pancreas

•Increased action of adrenocortical hormones which favor passage of glucose from mother to be given in excessive amounts as this causes a rebound effect, (=insulin level increases excessively in response to the excessive glucose and hypoglycemia will reappear)

•Hypoglycemia = blood calciun level less than 7mg %

     1. Clinical signs: same as hypoglycemia

     2. Management: calcium gluconate to prevent hypocalcemic tetany.

REFERENCE: Maternal and Child Health Nursing: 5th Edition by Adele Pillitteri

Continued use of glucose by the fetus may lead to hypoglycemia for the mother between meals. This is most apt to occur overnight.

She may become ketoacidotic from the breakdown of st