GESTATIONAL
DIABETES
DIABETES
DURING PREGNANCY
Definition.
Gestational
Diabetes Mellitus (GDM) is defined by abnormal Glucose
Tolerance during
pregnancy; the Glucose Tolerance Test is normal before, and which is usually
normal, after pregnancy.
 |
Gestational
Diabetes Mellitus
(GDM) is present in around 3-4% of all pregnancies.
| |
Gestational
Diabetes Mellitus
(GDM) can be associated with significant complications in fetus and newborn
including higher fatality rate.
| |
Thus,
it is important to rule out Gestational
Diabetes in all pregnancies. If not
feasible in all, at least all high risk patients must undergo the test.
|
High
Risk Patients For Gestational Diabetes. (GDM)
|
Women
who had GDM during a previous pregnancy.
| |
Women
with a first degree relative who is a diabetic.
| |
Women
who gave birth to large weight babies in a previous pregnancy.
| |
Women
whose newborn, in a previous pregnancy, showed any complication known to be
associated as arising from maternal GDM.
| |
Women
who gave birth to still born babies or infants with congenital
abnormalities.
| |
Women
with bad obstetric history, including recurrent fetal wastage, hypertension,
eclampsia (a pregnancy associated illness with fits), etc.
| |
Women
with repeated or persistent urinary tract infection.
| | Women
manifesting glycosuria (glucose positive in urine) during pregnancy.
| | Women
over the age of 30 years.
|
Diagnosis of
Gestational Diabetes.
Who should be
screened for diabetes?
 |
Ideally
, all pregnant women should be tested to rule out Gestational Diabetes. | |
All
high risk patients must undergo the test. |
Timing of test:
|
At
the start of third trimester (7 months onward) in all pregnant women. | |
Earlier
in patients with a bad obstetric history, even at first initial visit. |
Screening
Methods for diagnosis of Gestational Diabetes.
|
Initial
screening may be done by estimating the Fasting glucose levels and the levels 1
hour after an oral dose of 50 grams of glucose. |
|
This
test can be done in the fasting state or at any time; in the latter case,
only the one hour blood glucose value is taken into consideration for
diagnosis. |
Interpretation
of results.
| Patients
with a fasting venous whole blood glucose level of more than 80 mg% (venous
plasma glucose more than 90 mg%) |
or
| A
one hour post 100gms. glucose load venous whole blood glucose level of more
than 120 mg% (venous plasma blood glucose level of more than 140 mg%) |
or
|
A
random venous blood glucose level exceeding
105 mg % (plasma glucose more than 120 mg %) require a more comprehensive
test. |
Comprehensive
tests for GDM
The
Comprehensive test is same as for diagnosis of diabetes in non pregnant persons,
but the criteria differ.
|
. As per W.H.O.criteria, in addition
to the blood glucose levels in the diabetic range, values suggestive of
I.G.T (Impaired glucose tolerance)., seen in a pregnant woman, must also be
taken as diagnostic of Gestational
Diabetes. | |
Many
centers still use the O'Sullivan Criteria. |
O
Sullivan Criteria
 |
In this test, blood is
collected in the fasting state and then at 1, 2, and 3 hours intervals after an
oral load of 100 grams of glucose. | |
The presence of Gestational Diabetes is diagnosed
according to the following criteria: |
O
Sullivan Criteria
|
|
Venous
Plasma Glucose
(mg/100 ml)
|
Venous
Whole Blood Glucose
(mg/100 ml)
|
|
Fasting
1 hour
2 hour
3 hour |
105
190
165
145 |
90
165
145
125 |
|
Two
or more of the above values must be met or exceeded to make the
diagnosis of gestational
diabetes |
Interpretation
of results.
Two of the four values must be met to
diagnose GDM.
Significance
of GDM
 |
Women
with GDM may go on to have Diabetes in later life. | |
They must be considered as
having high risk for the development of Diabetes and must undergo annual
testing. |
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