Shock was writ all over her face and her husband’s. “How can I have diabetes,” asked the young woman. “When I saw the result of the blood sugar test, I thought it was a mistake. No one in my family has diabetes!” Well, that may be true, but it is also a fact that 2 per cent of the Indian population has diabetes and 15 per cent of pregnant women have abnormal blood glucose values.
Despite the epidemic of diabetes in our young urban adults, statistics about the exact prevalence of the disease in pregnancy are difficult to obtain. Many pregnant women are not tested. In centres offering antenatal care, the presence or absence of “sugar” in the urine — an unreliable test at best — is used to diagnose diabetes.
Blood should be tested as part of routine antenatal care. A fasting glucose level of more than 126mg/dL or 7mmols/L in pregnancy is considered abnormal. A blood sample can also be drawn one hour after ingesting 50g of glucose. A normal value is less than 140mg/dL or 7.8mmols/L. If it is higher, it needs to be followed by a three-hour OGTT (oral glucose tolerance test) with a 100g glucose load. A positive diagnosis is made if the fasting value is 105mg/dl, the one-hour value 190 mg/dL, the two-hour value 165mg/dL and the three-hour value 145 mg/dL or more.
Some of the women with these values are diabetics who are asymptomatic and unaware of their condition. Others have relative insulin insufficiency, or MODY (maturity onset diabetes of the young), and are already on oral diabetic medications. Women with polycystic ovarian syndrome may be on the oral diabetic drug metformin. They may become overtly diabetic during pregnancy.
Others with abnormal blood sugar levels have gestational diabetes mellitus (GDM), a peculiar type of glucose intolerance which first appears during pregnancy in an otherwise normal woman. It can occur at any time during the pregnancy, though it is more likely to occur after 24 weeks. The exact reason for gestational diabetes is not known.
Women at risk are those who:-
* Have a family history of diabetes,
* Are older than 25,
* Have previously had large babies (more than 4kg) or still births.
The glucose in the mother’s blood crosses over via the placenta to the baby. The excess sugar supplied makes the baby grow rapidly. The baby’s pancreas starts to work overtime to lower the sugar to normal by secreting insulin. The excess calories are stored as fat. This gives rise to a large baby (macrosomia) weighing more than 4kg. This in itself increases mortality by 50 per cent. The size may cause the baby to get stuck in the birth canal. Forceful extraction can result in fractures of the collarbone or paralysis of the nerves to the arm. After birth, the baby’s pancreas continues to produce high levels of insulin as it is acclimatised to do so. This may cause the blood sugar levels in the baby to drop precipitously. The baby may then have seizures. In addition, it may develop other problems such as low blood levels of calcium and magnesium. Many babies also die (that is, are still born) while others (up to 50 per cent) may have breathing difficulties.
About 33 per cent may have polycythemia (excess blood) and 16 per cent develop jaundice at birth or soon after.
Mothers with GDM are also prone to develop other complications during the pregnancy such as hypertension. Almost 60 per cent of these women develop GDM in subsequent pregnancies, particularly if there has been maternal weight gain between the two pregnancies. Around 35 per cent will go on to develop diabetes in the next 15 years. The blood sugar in mothers with GDM should be well controlled to prevent complications in her as well as the baby. Diet regulation is needed to keep the sugars under control. Since not all women with GDM are obese, the diet has to be adjusted in accordance with the mother’s BMI. The diet should consist of 40 per cent carbohydrate, 20 per cent protein and 40 per cent fat.
Pregnant women do not really “have to eat for two”. The calorie requirements are
*35kcal/kg/ 24hour for a woman of normal weight (BMI 25).
* 24kcal/kg/ 24hour for overweight women (BMI 25-30).
* 12 to 15 kcal/kg/24hour for morbidly obese women (BMI 30-40).
* 40kcal/kg/24hour for underweight women (BMI less than 25).
A combination of diet control and aerobic exercise such as brisk walking for 45 minutes every day usually keeps the blood sugars normal. If the sugars remain high, insulin therapy may have to be started. Many of the oral diabetic medications cross the placenta and cause hypoglycaemia in the baby. Some of them are, however, used under supervision.
Unlike other forms of diabetes, which are permanent, GDM disappears after delivery. It, however, acts as a warning. Exercise for 45 minutes or more a day, reduce your weight and maintain your BMI at 23. That way, diabetes may not plague you in your later years.
Source: The Telkegraph (Kolkata, India)