Gestational diabetes: The ‘bittersweet’ truth


Dr Madhu Pandey Singh, MD  (Obstetrics and Gynaecology)
Every so often we see news items about very large babies being born. Today’s article attempts to explain why this condition occurs and the steps that we can take to prevent it.

The word ‘diabetes’ usually evokes images of multiple painful blood tests, more painful injections and dieting. When your doctor tells you that you have developed diabetes in pregnancy (gestational diabetes) it is, if possible, even more worrisome because of the implications for the baby.

But there is hope, and with proper care you can ensure a healthy start for your baby.

Gestational diabetes:
This is a type of diabetes that affects only pregnant women. It is said to occur in 3-5% of the Caucasian pregnant women but the incidence is probably much higher in women of Asian origin.
Cause of gestational diabetes: The afterbirth (the placenta) produces hormones that sustain the growth of the pregnancy. Unfortunately some of these hormones break down the mother’s insulin thereby making her deficient in insulin.

As we are aware, insulin is a hormone needed to break down glucose (derived from starches and sugars) into energy. If the mother is unable to cope with the increased demand of insulin, due to the breakdown by the pregnancy hormones, she develops what is known as gestational diabetes.

This is a condition that usually develops between 20 and 24 weeks of pregnancy, which is roughly half way through the pregnancy.
Risk factors

There are certain risk factors that put a woman at greater risk of developing gestational diabetes.
These are:
* Age more than 25 years

* Family history of diabetes

* History of gestational diabetes in a

previous pregnancy

* Being overweight

* History of having large babies (more

than 3.75kg)

* History of previous still birth

* History of previous baby with a birth

Symptoms and signs

* These are usually very mild, if any. The usual classic symptoms of diabetes, increased thirst, urination and appetite may be confused with normal pregnancy associated symptoms.

* You may have repeated urinary tract infections.

* If your baby is suspected of being unusually large or if there is extensive fluid around the baby, you should be evaluated for diabetes.
Detection of gestational diabetes

If symptoms are mild or non-existent then how does one detect gestational diabetes? In modern obstetric care all pregnant women should be checked for blood sugar levels at different stages of their pregnancy (Type I Diabetes).

These tests may be done after administering a glucose containing drink. If this test is abnormal further testing may be needed to determine the severity of the problem.
Problems posed for the baby

As gestational diabetes affects women in the second half of pregnancy it is not usually associated with birth defects that are seen in babies born to mothers who have diabetes that antedates the pregnancy.

The underlying problem for the babies of gestational diabetics is the fact that excess sugar in the mother’s blood gets passed into the baby’s circulation. As a result the baby produces very high levels of its own insulin and stores all the extra glucose as fat. This baby becomes very large and is called ‘macrosomic.’
Problems for macrosomic babies

* Classically, macrosomic babies have big shoulders and therefore this may result in a difficult vaginal delivery.
* They have greater risk of developing breathing problems  – respiratory distress.

* They are at higher risk of developing low blood sugars after birth.

* They are at higher risk of still birth or death shortly after birth.
As adults these macrosomic babies are more prone to being overweight and diabetic.

Effects on the mother

Gestational diabetes increases the risk of:
* High blood pressure during pregnancy

* Caesarean delivery due to larger size of baby

* Gestational diabetes in subsequent pregnancies and developing diabetes later in life.
Management of gestational diabetes

As with other types of diabetes there is always a three-pronged approach to these patients including:
* Diet control

* Exercise

* Drug therapy
Diet control

Apart from advising the patient to avoid sugars and refined carbohydrates, serious diet control is not advocated in pregnancy. In fact, doctors are more inclined to allow a pregnant mother to eat a little bit more liberally than a non-pregnant diabetic and use insulin to control the blood sugar.

Mild to moderate exercise such as walking has a definite role in mild diabetics. In fact we have seen patients completely control mild gestational diabetes just by regular mild to moderate exercise along with avoiding refined sugars. Severe gestational diabetics, however, will need medication.
Drug therapy

In spite of all the research into using oral diabetes medication during pregnancy, insulin still remains the gold standard as oral medications have multiple undesirable side effects on the baby.

The drawback with insulin therapy is the multiple injections it entails on a daily basis. However, insulin has dramatically changed the outcome for pregnant diabetic patients and is still advocated as the best alternative.

There is a myth in Guyana about insulin use in pregnancy. Using insulin in pregnancy does not imply that the patient will have to use it for the rest of their lives. Even those patients that remain diabetic after the pregnancy is over, are successfully converted to oral medications after delivery of the baby.
Time of delivery

Diabetic mothers are prone to having sudden intrauterine demise of the baby, so usually the obstetrician, would like to time the birth of the baby soon after the baby’s lungs are mature which is at 37 to 38 weeks – that is a couple of weeks before the due date.
Mode of delivery

Once the mother has had good care during her pregnancy and her blood sugars have been controlled adequately, the baby should not be very big and therefore a normal vaginal delivery is possible. Not every patient will need a caesarean section just because she is diabetic.

In conclusion, gestational diabetes management needs a vigilant care provider along with a co-operative patient and family, because of the compliance needed due to the painful injections that the treatment may entail. The outcome depends in equal measure on the doctor and the patient with a supportive family.

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