High Risk Pregnancy: Pre-Existing Conditions
Diabetes Mellitus
the body cannot produce/utilize adequate insulin to regulate blood glucose levels
(insulin normally enables glucose to move from the blood into the cell
...
High Risk Pregnancy: Pre-Existing Conditions
Diabetes Mellitus
the body cannot produce/utilize adequate insulin to regulate blood glucose levels
(insulin normally enables glucose to move from the blood into the cells)
Without adequate insulin, glucose does not enter the cells and they become
energy depleted
Blood glucose levels remain high (hyperglycemia), and the cells break down their
stores of fats and protein for energy
Protein breakdown results in negative nitrogen balance; fat metabolism causes
ketosis
Diagnosis of diabetes is based on the presence of clinical symptoms and lab tests
showing elevated glucose levels in the blood, glycosuria, and ketoacidosis.
o Polyuria
Frequent urination
Results b/c water is not reabsorbed by the renal tubules due to the
osmotic activity of glucose
o Polydypsia
Excessive thirst
Caused by dehydration from polyuria
o Polyphasia
Excessive hunger
Caused by tissue loss and a state of starvation, which results from
the inability of the cells to use the blood glucose
o Weight loss
Seen with marked hyperglycemia
Due to the use of fat and muscle tissue for energy
Diabetes in Pregnancy
Gestational diabetes mellitus (GDM) is defined as any degree of glucose
intolerance that has its onset or its first diagnosed during pregnancy.
This can cause increased risk for perinatal morbidity and mortality. Women with
GDM have increased chances of overt type 2 diabetes.
This is NOT a preexisting condition.
Pregnancy impact on DM and DM impact on pregnancy
o Pregnancy can affect diabetes significantly because the physiologic
changes of pregnancy can drastically alter insulin requirements. Pregnancy
may also alter the progress of vascular disease secondary to DM.
o DM may be difficult to control b/c insulin requirements are changeable
o During the 1st trimester, the need for insulin frequently decreases. Levels
of hPL, an insulin antagonist, are low; fetal needs are minimal; and the
woman may consume less food b/c of n/v.
o N/V may cause dietary fluctuations and increase the risk of hypoglycemia,
formerly called insulin shock.
o Insulin requirements begin to rise late in the first trimester as glucose use
and glucose storage by the woman and fetus increase. Insulin
requirements may double or quadruple by the end of pregnancy as a result
of placental maturation and hPL production.
o Increased energy needs during labor may require increased insulin to
balance IV glucose.
o After delivery of the placenta, insulin requirements usually decrease
abruptly as a result of the loss of hPL in maternal circulation.
o A decreased renal threshold for glucose leads to a higher incidence of
glycosuria.
OB Exam 4: High risk pregnancy
o The risk of ketoacidosis, which may occur at lower serum glucose levels in
the pregnant woman with DM than in the nonpregnant woman with
diabetes, increases.
o The vascular disease that accompanies DM may progress during
pregnancy.
o HTN may occur, contributing to vascular changes.
o Nephropathy may result from renal impairment, and retinopathy may
develop (from occlusion of the microscopic blood vessels of the eye
Risks of Diabetes during Pregnancy
Maternal Risks Infant Risks
Hydramnios
o Increase in volume of
amniotic fluid
o Thought to be a result of
excessive fetal urination b/c
of fetal hyperglycemia.
o Increased risk for premature
rupture of membranes and
onset of labor
pre-eclampsia/eclampsia
o More at risk than normal
preg, esp when vascular
changes already exist
Hyperglycemia/ketoacidosis
o D/t insufficient amounts of
insulin
o Can lead to ketoacidosis as a
result of the increase in
ketone bodies (they are
acidic) released in the blood
from the metabolism of fatty
acids
o Decreased gastric motility
and the anti-insulin effects of
hPL also predispose the
woman to ketoacidosis.
o Ketoacidosis usually
develops slowly but, if
untreated, can lead to coma
and death for mother and
fetus.
Labor dystocia
o Means a difficult labor
o Caused by fetopelvic
disproportion if fetal
macrosomia exists
Worsening of diabetic
complications (vascular,
retinopathy)
o Good control of blood
glucose levels lessens the
impact
o Women with preexisting
diabetes should be referred
Many of the problems of the newborn result
directly from high maternal plasma glucose
levels. In the presence of untreated maternal
ketoacidosis, the risk of fetal death increases
dramatically
Congenital anomalies
o Major cause of death of babies born to
women with diabetes.
o Most anomalies involve the heart, central
nervous system, and skeletal system.
o Sacral agenesis appears almost
exclusively in newborns of mothers with
diabetes. In this, the newborns sacrum
and lumbar spine fail to develop and the
lower extremities develop incompletely
o Preconception counseling and strict
diabetes control before conception help
reduce the incidence of congenital
anomalies
LGA
o As a result of high levels of fetal insulin
production stimulated by the high levels
of glucose crossing the placenta from the
mother. The elevated levels continually
stimulate the fetal islets of Langerhans to
produce insulin. This hyper insulin state
causes the fetus to use the available
glucose, which leads to excessive growth
(macrosomia) and fat deposits.
o If born vaginally, the macrosomic neonate
is at increased risk for shoulder dystocia
and traumatic birth injuries so C-section
may be considered if the birth wt is
expected to exceed 4500 g
o Macrosomia can be significantly reduced
by strict maternal blood glucose control.
IUGR
o Infants of mothers with advanced diabetes
(vascular involvement) may demonstrate
intrauterine growth restriction (IUGR),
which occurs b/c vascular changes in the
mother decrease the efficiency of
placental perfusion and the fetus is not as
well sustained
[Show More]
.png)
 (1).png)
