Hyperglycaemia (High Blood Glucose) in Pregnancy

Dr VK Abhichandani shares the importance of blood glucose management during pregnancy
Hyperglycaemia (High Blood Glucose) in Pregnancy

Hyperglycaemia is the most typical medical condition affecting pregnancy, and its incidence is increasing globally in parallel with the twin epidemics of Diabetes and obesity. Both pre-pregnancy Diabetes and gestational Diabetes are associated with short-term pregnancy complications, with the risk of immediate complications generally broadly rising with more severe hyperglycaemia. Hyperglycaemia in pregnancy” (HIP) is an umbrella term covering all degrees of hyperglycaemia.

This broad category is then separated into (overt) “Diabetes in pregnancy” (DIP) (characterized by glucose levels consistent with Diabetes, diagnosed either before or during the index pregnancy) and “Gestational Diabetes” (GDM), which comprises a large majority of HIP cases. Gestational Diabetes mellitus (GDM) is defined as glucose intolerance of variable degree with onset or first recognition during pregnancy. “Pre-pregnancy Diabetes” describes those cases in which Diabetes is known to have been present before pregnancy. This category includes Type 1 Diabetes (T1D), Type 2 Diabetes (T2D), and other specific subTypes, including monogenic Diabetes (Some rare forms of Diabetes result from mutations or changes in a single gene and are called monogenic or Maturity-Onset Diabetes of the Young - MODY)

What is Insulin?

Insulin is produced in the beta cells of the pancreas. When we eat food your blood sugar rises and our pancreas releases insulin into our blood stream. The insulin allows our liver, muscle, and fat to absorb glucose Type 1 Diabetes is an autoimmune disease that causes damage to the beta cells of the pancreas, so little to no insulin can be produced. Hence, insulin injections are necessary. Type 1 Diabetes is typically diagnosed in children and young adults. It is not related to prediabetes.

Type 2 Diabetes progresses differently from Type 1 Diabetes. With Type 2, the pancreas produces insulin, but the body loses sensitivity to it, so blood glucose levels rise. To compensate, the pancreas produces more insulin. Over time, the pancreas cannot produce enough insulin to bring down blood glucose levels adequately, and they continue to rise.

What is gestational Diabetes mellitus?

Gestational Diabetes mellitus (GDM) is a condition in which a hormone made by the placenta prevents the body from using insulin effectively. Glucose builds up in the blood instead of being absorbed by the cells.

Unlike Type 1 Diabetes, gestational Diabetes is not caused by a lack of insulin, but by other hormones produced during pregnancy that can make insulin less effective, a condition referred to as insulin resistance. Gestational diabetic symptoms mostly disappear following delivery.

Gestational Diabetes mellitus (GDM) is the most prevalent disease among pregnant women, affecting up to 15-25 per cent of pregnancies worldwide.

What causes larger foetus size (macrosomia) when the mother has gestational Diabetes mellitus?

The placenta supplies a growing foetus with nutrients and water, and also produces a variety of hormones to maintain the pregnancy. Some of these hormones (oestrogen, cortisol, and human placental lactogen) can have a blocking effect on insulin. This is called counter-insulin effect, which usually begins about 20 to 24 weeks into the pregnancy.

As the placenta grows, more of these hormones are produced, with increase of insulin resistance. Normally, the pancreas is able to make additional insulin to overcome insulin resistance, but when the production of insulin is not enough to overcome the effect of the placental hormones, gestational Diabetes results.

What are the risks factors associated with gestational Diabetes mellitus?

Although any woman can develop GDM during pregnancy, some of the factors that may increase the risk include the following:

•   Overweight or obesity

•   Family history of Diabetes. In India, one-third (33 per cent) of women with GDM have a history of maternal Diabetes

•   Having given birth previously to an infant weighing greater than 4 kg

•   Age- women who are older than 25 are at a greater risk for developing gestational Diabetes than younger women

•   Race- women who are African-American, American Indian, Hispanic or Latino, Pacific Islander and Asian Indians have a higher risk.

•   prediabetes, also known as impaired glucose tolerance or impaired fasting glucose is a condition where the blood glucose levels are higher than normal but not high enough to be diagnosed as Type 2 Diabetes. Women of child bearing age with prediabetes are at a higher risk of developing Type 2 Diabetes, heart disease, and stroke.

How is gestational Diabetes mellitus diagnosed?

The American Diabetes Association recommends screening for undiagnosed Type 2 Diabetes at the first prenatal visit in women with Diabetes risk factors. In pregnant women not known to have Diabetes, GDM testing should be performed at 24 to 28 weeks of gestation.

The Diabetes in Pregnancy Study Group India (DIPSI) recommends diagnosing gestational Diabetes mellitus (GDM) if a pregnant woman's venous plasma glucose level is 140 milligrams per decilitre (mg/dL) or higher two hours after consuming 75 grams of glucose. This test can be performed regardless of whether the woman is fasting or when she ate last.

In addition, women with diagnosed GDM should be screened for persistent Diabetes 6 weeks after delivery. It is also recommended that Indian women with a history of GDM undergo lifelong screening for the development of Diabetes or prediabetes annually.

What is the treatment for gestational Diabetes mellitus?

Specific treatment for gestational Diabetes will be determined by the doctor based on:

.The woman's age, overall health, and medical history

.Degree of Hyperglycemia

.Expectations for the course of her disease

.Her opinion or preference for offered therapy

Treatment for gestational Diabetes focuses on keeping blood glucose levels in the pregnancy specific normal range.

Treatment may include:

. Special diet

. Exercise

. Daily blood glucose monitoring

. Insulin injections

After a pregnant woman is diagnosed with gestational Diabetes, she will need to make changes in what she eats and learn to check her blood glucose level. She may also be advised to get more exercise. If changing her diet and activity doesn't result in normal blood glucose levels, she will also need to learn how to give herself insulin injections or take a pill (metformin) to lower blood glucose levels

Prioritization of the health and well-being of both mother and child is crucial for an effective management of GDM. The administration of metformin has been shown to increase the likelihood of obesity and T2D in the offspring, thus outweighing any potential advantages for the mother.

Hence, it is appropriate to consider metformin as a suitable treatment choice for GDM only when insulin is not a viable first choice.

Eating plan - The first treatment for gestational Diabetes is eating right. A dietitian, nurse, or certified diabetic educator (a nurse or dietician that specializes in Diabetes) will be involved in planning the lifestyle and dietary modifications for the pregnant lady with hyperglycemia. The general guidelines include:

•    Continue to eat a healthy pregnancy diet.

•    Avoid sweet desserts and presweetened beverages. This includes candy, cake, cookies, ice cream, donuts, jams and jellies, syrups, and sweet sauces. Also avoid adding sugar to your food or drinks, sweetened soda, punch, sweet tea, and other fruity beverages.

•    Use of alternative sweeteners aspartame (NutraSweet), sucralose (Splenda), stevioside (Stevia), or acesulfame potassium (Sunnet) [though believed not to increase the risk of birth defects], is recommended only in moderation

•    Consume protein with limited saturated fat, such as trimmed red meat and pork, chicken, and fish. Other protein foods like cheese, eggs, nuts, seeds, and peanut butter are also good source of nourishment.

•    Eat moderate portions of complex carbohydrate (natural starches and sugars) containing foods.

•    Starchy foods (e.g., breads, rice, pasta, potato, corn, cereals). Starchy foods eventually turn into glucose so it's important not to be excessive. However, starch should be included in every meal. A reasonable portion is about one cup of total starch per meal, or two pieces of bread. Choose whole grains over refined grains.

•    Fruits and fruit juices Limit fruit servings to a small piece of fruit or approximately 1 cup at a time. Avoid fruit juice or limit 100 percent fruit juice to one-half cup (4 ounces) per serving.

•    Milk and yogurt Skim or 1 percent milk is healthiest. Choose low-fat yogurt that is plain, "light," or Greek style.

•    Many vegetables are low in sugar and carbohydrates. Include plenty of salads, greens (spinach, collards, kale), broccoli, carrots, green beans, tomatoes, onions, mushrooms, and other vegetables you enjoy. Half of the plate at the meals can be non-starchy vegetables.

•    Use healthy fats, like olive or canola oil.

Blood sugar monitoring - Every pregnant lady with hyperglycemia should learn how to check her blood glucose level and record the results. Education for choosing a blood sugar meter, checking blood glucose levels at home, and ways to record the results will be imparted by the Diabetes care team

Initially, most individuals should check their blood glucose level four times per day:

•    Before eating in the morning

•    One or two hours after the first bite of food with breakfast, lunch, and dinner

This information can help to determine whether her blood glucose levels are on target. If the levels stay higher than they should be, her doctor will probably recommend using insulin therapy.

Exercise - might help to control blood glucose levels. If you were exercising before, you should continue after being diagnosed with gestational Diabetes.

If you did not previously exercise, ask your doctor or nurse if exercise is  recommended. Most ladies with HIP who do not have medical or pregnancy-related complications are able to exercise, at least moderately, throughout their pregnancy. Walking is a great form of exercise for those starting an exercise regimen

Insulin - About 15 to 30 per cent of women with gestational Diabetes (GDM) need insulin therapy. Insulin is a medicine that helps to reduce blood glucose levels and can reduce the risk of gestational Diabetes- related complications. Insulin is the most common medicine for treating gestational Diabetes.

Most pregnant people with GDM do well with just one to two shots of insulin per day. If the blood glucose levels remain persistently high after eating, the lady may need to take insulin shot three or four times per day.

While on insulin, blood glucose level should be checked at least four times per day.

Blood glucose levels should be noted down along with how much insulin was injected. These records should be viewed by the doctor at each prenatal visit or more frequently based on her doctor's recommendation. Keeping accurate records helps to adjust insulin doses and can decrease the risk of complication.

Eat three small-sized meals and three to four healthy snacks. Eat every two to three hours to space food evenly throughout your day. She is best advised not skip meals or snacks. The bedtime snack is especially important to help keep her fasting (first blood sugar of the day before eating) in range and at the same time prevent early morning (2 to 3 am) hypoglycemia.

Generally, insulin therapy is preferred for pregnant patients with Diabetes who cannot control blood glucose levels adequately by their diet (nutritional therapy). Insulin is effective and safe and does not cross the placenta to the fetus. Most oral Diabetes medicines pass from the pregnant individual to their baby through the placenta; while they have not been shown to harm the fetus or newborn, it is not known if there are longer term effects on children. However, oral anti-hyperglycemic agents may be offered to individuals who will not take, or are unable to comply with, insulin therapy, if they understand the lack of information on long-term risks or benefits.

Monitoring During Pregnancy

Prenatal visits - Most pregnant individuals who develop gestational Diabetes require more frequent prenatal visits (e.g., once every week), especially if insulin is used.

The purpose of these visits is to monitor her and her baby's health, discuss her diet, review her blood sugars, and adjust her dose of insulin to keep her blood glucose levels near normal. It is common to change the dose of insulin as the pregnancy progresses. She may also be asked to have one or two ultrasound examinations to check on the growth and size of the baby.

Non-stress testing - The lady with HIP  may need tests to monitor the health of the baby during the later stages of pregnancy, especially if her blood sugars have been high, she is already using insulin, or if she has any pregnancy-related complications (e.g., high blood pressure). The most used test is the non-stress test. A non-stress test (NST) is a test in pregnancy that measures fetal heart rate in response to movement and contractions. Results are either reactive or non-reactive. Non-reactive results don't mean there's a problem, but they can mean more tests may be necessary

Labor and delivery with GDM

If the blood glucose levels are close to normal during pregnancy and lady has no other complications, the ideal time to give birth is between 39 and 40 weeks of pregnancy, no later than her due date.

If she does not deliver by her due date, she may be offered induction of labor or additional testing to monitor her and her baby's health.

In most individuals with gestational Diabetes and a normal-size baby, there are no advantages to a cesarean over a vaginal birth. Those with a very large baby may be offered cesarean birth before labor starts.

Patient's blood glucose levels will be monitored during labor. Most GDM ladies have normal blood glucose levels during labor and do not need any insulin. Insulin is given if the blood glucose level becomes high. High blood glucose levels during labor can cause problems in the baby, both before and after delivery.

After-Delivery Care

After giving birth, most individuals with gestational Diabetes have normal blood glucose levels and do not require further treatment with insulin. She can return to her pre-pregnancy diet and must be encouraged to breastfeed.

However, her doctor may check her blood glucose level the for a day or two after delivery to be sure that it is normal or near normal. Having gestational Diabetes does substantially increase a GDM lady's risk of developing Type 2 Diabetes later in life.

After the delivery, she should have testing for Type 2 Diabetes. Typically, this is done at six weeks postpartum besides being done in the hospital before the GDM lady is discharged. Testing usually includes a two- hour glucose tolerance test (GTT) so that she is tested for both pre-Diabetes and Diabetes. It is also recommended that Indian women with a history of GDM undergo lifelong screening for the development of Diabetes or prediabetes annually.

Risk of recurrent gestational Diabetes

One-third to two-thirds of women who have gestational Diabetes in one pregnancy will have it again in a later pregnancy. If they are overweight or obese, weight reduction through diet and exercise can reduce this risk.

Risk of developing Type 2 Diabetes

Individuals with gestational Diabetes have an increased risk of developing Type 2 Diabetes later in life, especially if they have other risk factors (e.g., family history of Type 2 Diabetes).

The risk of developing Type 2 Diabetes is greatly affected by body weight. Individuals with obesity have a 50 to 75 per cent risk of developing Type 2 Diabetes, while this risk is less-than-25 per cent in those who are a normal weight. It is recommended that a woman with history of GDM must eat a healthy diet, lose any excess weight, and exercise regularly to help decrease her

risk of developing Type 2 Diabetes.

Cardiovascular disease - Females who have had gestational Diabetes in the past are at increased risk of developing cardiovascular disease, including heart attack and stroke. While this is mostly tied to the risk of Type 2 Diabetes, even those who do not develop Type 2 Diabetes appear to have a noticeable increase in their risk of heart disease later in life. Continuing to make healthy lifestyle choices such as eating a balanced diet, exercising regularly, and avoiding smoking can help minimize this risk.

Why knowledge of GDM is important

GDM increases the risk of pregnancy hypertension, pre-eclampsia (Preeclampsia is a serious pregnancy condition that can cause high blood pressure, protein in the urine, and swelling.), caesarean birth, amniotic fluid excess, preterm membrane rupture, and ketoacidosis as short-term side effects. Furthermore, the long-term detrimental effects of GDM on the mother include cardiovascular disease and metabolic syndrome in addition to Type 2 Diabetes.

Moreover, GDM raises the danger of neonatal complications such as birth injuries, respiratory distress syndrome, hyperbilirubinemia, and hypoglycaemia.

Dr VK Abhichandani is consulting Endocrinologist in Ahmedabad.

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