About

This is a type of diabetes (also called Gestational Diabetes) that

some women get during pregnancy (especially during 3rd trimester).

Between 2 and 10 percent of expectant mothers develop this

condition characterized by high blood sugar, making it one of the

most common health problems of pregnancy.

It usually disappears after the birth, and does not mean that

the baby will be born with diabetes

Causes

Gestational diabetes is caused by hormonal changes in pregnancy

which can change the body’s ability to use a substance called

insulin. Insulin is important because it helps keep blood sugar at a

healthy level. Whilst all women undergo hormonal changes, only

some women develop gestational diabetes.

This is likely due to pregnancy related factors such as the

presence of human placental lactogen that interferes with

susceptible insulin receptors.

Symptoms & Risks

Gestational diabetes usually has no symptoms. That's why

almost all pregnant women have a glucose-screening test

between 24 and 28 weeks.

Risks:

1. Being overweight prior to becoming pregnant (if you are

20% or more over your ideal body weight)

2. Being a member of a high risk ethnic group (Hispanic,

Black, Native American, or Asian)

3. Having sugar in your urine

4. Impaired glucose tolerance or impaired fasting glucose (blood

sugar levels are high, but not high enough to be diabetes)

5. Family history of diabetes (if your parents or siblings have

diabetes

6. Previously giving birth to a baby over 9 pounds

7. Previously giving birth to a stillborn baby

8. Having gestational diabetes with a previous pregnancy

9. Having too much amniotic fluid (a condition called

polyhydramnios)

Diagnosis

High risk women should be screened for gestational diabetes as

early as possible during their pregnancies. All other women will be

screened between the 24th and 28th week of pregnancy.

To screen for gestational diabetes, an oral glucose tolerance test is

done. This test involves quickly drinking a sweetened liquid, which

contains 50g of sugar. The body absorbs this sugar rapidly, causing

blood sugar levels to rise within 30-60 minutes. A blood sample will

be taken from a vein in the arm 1 hour after drinking the solution.

The blood test measures how the sugar solution was metabolized.

A blood sugar level greater than or equal to 140mg/dL is

recognized as abnormal. If your results are abnormal based on the

oral glucose tolerance test, another test will be given after fasting

for several hours.

In women at high risk of developing gestational diabetes, a normal

screening test result is followed up with another screening test at

24-28 weeks for confirmation of the diagnosis.

Pathophysiology

The precise mechanisms remain unknown. There is increased

insulin resistance. Pregnancy hormones and other factors interfere

with the action of insulin as it binds to the insulin receptor. The

interference probably occurs at the level of the cell signaling

pathway behind the insulin receptor. Since insulin promotes the

entry of glucose into most cells, insulin resistance prevents glucose

from entering the cells properly. As a result, glucose remains in the

bloodstream, where glucose levels rise. More insulin is needed to

overcome this resistance; about 1.5-2.5 times more insulin is

produced than in a normal pregnancy.

Diabetic Diagnostic

Criteria

Condition 2 hour glucose Fasting glucose

HbA1c

mmol/l(mg/dl) mmol/l(mg/dl) %

Normal <7.8(<140) <6.1(<110) <6.0

Impaired fasting glycaemia <7.8(<140) >6.1(>110) & <7.0(<126) 6.0 - 6.4

Impaired Glucose Tolerance >7.8(>140) <7.0 (<126) 6.0 – 6.4

Diabetes mellitus >11.1(>200) >7.0 (>126) >6.5

Management

The goal of treatment is to reduce the risks of GDM for mother and

child. Scientific evidence is beginning to show that controlling

glucose levels can lessen serious fetal complications and increase

maternal quality of life.

Lifestyle:

1. Eating a balanced diet of wholegrain carbohydrates, lean

proteins and healthy fats.

2. Regular moderately intense physical exercise is advised

3. Any diet needs to provide sufficient calories for pregnancy,

typically 2,000 - 2,500 kcal with the exclusion of simple

carbohydrates.

4. The main goal of dietary modifications is to avoid peaks in blood

sugar levels. This can be done by spreading carbohydrate intake

over meals and snacks throughout the day, and using slow-release

carbohydrate sources—known as the G.I. Diet.

5. Since insulin resistance is highest in mornings, breakfast

carbohydrates need to be restricted more. Ingesting more fiber in

foods with whole grains, or fruit and vegetables can also reduce the

risk of gestational diabetes.

Self monitoring can be accomplished using a handheld capillary

glucose dosage system. Compliance with these glucometer

systems can be low.

Target ranges advised are:

Fasting capillary blood glucose levels <5.5 mmol/L

1 hour postprandial capillary blood glucose levels <8.0 mmol/L

2 hour postprandial blood glucose levels <6.7 mmol/L

Medication:

Taking insulin, if necessary. Insulin is currently the only diabetes

medication used during pregnancy.

Care needs to be taken to avoid low blood sugar levels

(hypoglycemia) due to excessive insulin injections. Insulin therapy

can be normal or very tight; more injections can result in better

control but requires more effort.

Glyburide, a second generation sulfonylurea, has been shown to

be an effective alternative to insulin therapy.

Metformin has shown promising results, with its oral format being

much more popular than insulin injections.

But half of patients did not reach sufficient control with metformin

alone and needed supplemental therapy with insulin; compared to

those treated with insulin alone, they required less insulin, and they

gained less weight. There is a possibility of long-term complications

from metformin therapy, although follow-up at the age of 18 months

of children born to women with POS and treated with metformin

revealed no developmental abnormalities.

Complications

Most women who have gestational diabetes deliver healthy babies.

However, gestational diabetes that's not carefully managed can

lead to uncontrolled blood sugar levels and cause problems for you

and your baby, including an increased likelihood of needing

delivery by C-section.

Complications that may affect the baby :

1. Excessive birth weight:

Extra glucose in your bloodstream crosses

the placenta, which triggers your baby's pancreas to make extra

insulin. This can cause your baby to grow too large (macrosomia).

2. Preterm birth and respiratory distress syndrome:

Maternal high blood sugar may increase

her risk of going into labor early and delivering her baby before its

due date. Or the doctor may recommend early delivery because the

baby is growing so large. Babies born early may experience

respiratory distress syndrome. Babies with this syndrome may

need help breathing until their lungs mature and become stronger.

Babies of mothers with gestational diabetes may experience

respiratory distress syndrome even if they're not born early.

3. Low blood sugar (hypoglycemia):

Sometimes babies develop low blood

sugar (hypoglycemia) shortly after birth because their own insulin

production is high. Severe episodes of hypoglycemia may provoke

seizures in the baby. Prompt feedings and sometimes an

intravenous glucose solution can return the baby's blood sugar

level to normal.

4. Jaundice:

This yellowish discoloration of the skin

and the whites of the eyes may occur if a baby's liver isn't mature

enough to break down a substance called bilirubin. Although

jaundice usually isn't a cause for concern, careful monitoring is

important.

5. Type 2 diabetes later in life: Babies of mothers who have

gestational diabetes have a higher risk of developing obesity and

type 2 diabetes later in life.

Untreated gestational diabetes can result in a baby's death either

before or shortly after birth.

Complications that may affect the mother:

1. High blood pressure, preeclampsia and eclampsia:

Increases the risk of developing high

blood pressure during pregnancy & risk of preeclampsia and

eclampsia — two serious complications of pregnancy that cause

high blood pressure and other symptoms that can threaten the lives

of both mother and baby.

2. Future diabetes:

Risks to develop gestational diabetes in a

future pregnancy. More likely to develop type 2 diabetes later.

However, making healthy lifestyle choices such as eating healthy

foods and exercising can help reduce the risk of future type 2

diabetes. Of those women with a history of gestational diabetes

who reach their ideal body weight after delivery, fewer than one in

four develop type 2 diabetes.

Prognosis

Gestational diabetes generally resolves once the baby is born. The

risk is highest in women who needed insulin treatment, had antibodies

associated with diabetes, women with more than two previous

pregnancies, and women who were obese (in order of importance).

Women requiring insulin to manage gestational diabetes have a 50%

risk of developing diabetes within the next five years.

Children of women with GDM have an increased risk for childhood

and adult obesity and an increased risk of glucose intolerance and

type 2 diabetes later in life.