Pregnancy causes several hormonal changes, which, coupled with weight gain, could block insulin’s function to control blood sugar levels, leading to insulin resistance. Generally, most pregnant women can overcome insulin resistance, but some can’t and develop gestational diabetes (1). Gestational diabetes mellitus (GDM) is a diabetes type that appears in non-diabetic women during pregnancy.
It causes high blood sugar levels in maternal blood, exposing her and her unborn baby to several health complications, such as preeclampsia and premature birth (2). Although most women can manage GDM and have a healthy pregnancy with healthy eating and an active lifestyle, some may need insulin. The good news is that GDM resolves soon after childbirth in most cases.
Keep reading to know the symptoms, risk factors, diagnosis, treatment, and effective management of gestational diabetes.
Symptoms Of Gestational Diabetes
- Unusual thirst
- Frequent urination
- Frequent infections of the skin, vagina, and bladder
- Blurred vision
If you have these symptoms, get yourself tested for gestational diabetes. According to the American Diabetes Association (ADA), “nearly ten percent of pregnancies in the US are affected by gestational diabetes every year.”(5)
Causes Of Gestational Diabetes
During pregnancy, the placenta acts as the source of nourishment for the fetus and produces hormones to maintain pregnancy. But, some of these hormones, such as estrogen, cortisol, and human placental lactogen, can block insulin functioning (contra-insulin effect), triggering insulin resistance. Insulin is a hormone produced by the beta-cells of the pancreas that helps the body’s cells absorb glucose, regulating blood sugar levels.
At first, the mother’s body produces more insulin to overcome insulin resistance. But, as the pregnancy progresses, insulin production fails to overcome the contra-insulin effect, resulting in gestational diabetes. Several risk factors raise a pregnant woman’s chances of developing GDM. The next section gives an insight into them.
Risk Factors For Gestational Diabetes
According to the Centers for Disease Control and Prevention (CDC), some pregnant women have insulin resistance before pregnancy, raising their chance of developing GDM (7). Besides this, the other risk factors for GDM are (2):
- Age above 25 years
- Family history of diabetes
- Overweight or obesity
- Physical inactivity during pregnancy
- Gestational diabetes in the previous pregnancy
- Previously delivering a baby weighing more than nine pounds
- Previous unexplained miscarriage or stillbirth
- Intake of certain medications, such as glucocorticoids
- Presence of chronic health issues, such as polycystic ovarian syndrome (PCOS), high blood pressure, and heart disease
Some women may have type-1 or type-2 diabetes before they conceive. Although the etiology of both types of diabetes varies, both raise the risk of GDM.
According to John Hopkins Medicine, women of certain gene pools, such as Hispanic, Native American, Asian American, and African-American, may have a higher risk of developing gestational diabetes (6).
Diagnosis Of Gestational Diabetes
Insulin resistance (contra-insulin effect) usually begins between the 20th and 24th week of pregnancy(6). Therefore, all pregnant women are tested for gestational diabetes during a routine checkup between the 24th and 28th week of pregnancy as a part of prenatal care (3). If a woman has risk factors for gestational diabetes, a doctor may test for GDM earlier in the pregnancy.
1. Glucose challenge test
It’s the first test that the doctor will perform to diagnose GDM. For the test, the doctor will ask you to drink a sweet liquid containing 50g of sugar/glucose. Then, after an hour, they will run a blood test to measure your blood sugar level.
If your blood sugar level is greater than or equal to 140mg/dL (7.8 mmol/L), the doctor will order the oral glucose tolerance test. If your sugar level is greater than equal to 200mg/dL, you may have type-2 diabetes.
2. Oral glucose tolerance test (OGTT)
Unlike the glucose challenge test, the OGTT measures fasting and non-fasting glucose levels. The test first requires you to fast for at least eight hours. Then, your healthcare professional will take your blood sample and give you a sweet liquid containing 75g of sugar/glucose dissolved in 300 ml of water to drink.
The doctor will check your sugar level every hour for two to three hours. If any two or more readings (fasting, one hour, or two hours) are higher than or equal to the values shared below, it indicates you have GDM.
|Mealtime||Blood Sugar Levels (mg/dL)|
|After one hour||180|
|After two hours||153|
Source: National Center for Biotechnology Information (NCBI)
Glucose testing at the first prenatal visit is recommended if a woman has one or more diabetes risk factors. In some cases, the doctor may also advise urinalysis to test glucose in the urine, indicating gestational diabetes.
Management And Treatment For Gestational Diabetes
Most women can manage gestational diabetes with healthy eating, an active lifestyle, and medication (if necessary) (10).
1. Healthy eating
Women with GDM should follow a personalized diet plan based on their sugar levels, activity levels, and overall health. A diet expert or certified nutritionist will help you plan a well-balanced diet plan with details, such as what to eat, how much to eat, and when to eat. Besides, they can ask you to:
- Space your meals at regular intervals and eat every two to three hours. It’s a vital step while eating carbs, as spacing out carb-rich foods helps control sugar levels.
- Eat more complex carbs, such as whole grains, low-sugar fruits, and starchy veggies.
- Eat two to three servings of high-quality protein foods, such as fatty fish, non-fat or low-fat dairy, lean meat, and soy products, such astofu.
- Include heart-healthy, omega-3-rich foods, such as avocado, unsalted nuts, seeds, and olive oil.
Women with GDM are at a high risk of developing type-2 diabetes during their lifetime. Hence, healthy eating is vital to maintain a healthy weight and safe sugar levels during and after pregnancy.
2. Active lifestyle
Indulging in moderate-intensity physical activity or exercise for 30 minutes, five days a week, can help keep your sugar levels within the desired target range. Besides, it can also help relieve stress, strengthen muscles, and keep joints flexible. Speak to your doctor about the appropriate activities based on your health and pregnancy stage. Generally, walking ten to 15 minutes after each meal can help have better blood sugar control.
Healthy dietary and lifestyle changes can help manage blood sugar levels within recommended limits for most women. However, if these changes don’t prove effective, you may need oral hypoglycemic drugs or insulin. Your doctor will guide you on a suitable medication/insulin course. They will also teach you the way to self-inject insulin. Injectable insulin is safe as it doesn’t cross the placenta and doesn’t affect the baby (2).
4. Monitor sugar levels
Regular monitoring of sugar levels is vital for the effective management of GDM. Use a glucometer to monitor your blood sugar levels at different intervals throughout the day. Note the readings in a diary or your phone and maintain a track that you and your doctor can check to evaluate if your diabetes management plan is working.
Here are the daily target blood glucose levels for most women with GDM (10).
|Mealtime||Target Sugar Levels (mg/dL)|
|Before meals, at bedtime, and overnight||Less than or equal to 95|
|One hour after eating||Less than or equal to 140|
|Two hours after eating||Less than or equal to 120|
Source: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Based on your overall health and BMI, your doctor will decide on individualized blood sugar targets for you. To attain and maintain those targets, you should diligently follow your diet, activity, and medicine schedules.
Experts recommend testing sugar levels for six weeks after delivery for women with GDM. If the sugar levels are normal, the doctor will order a re-evaluation after a year. However, if the sugar levels are abnormal, your doctor may provide guidance on diabetes management and prevention.
Possible Complications Of Gestational Diabetes
In gestational diabetes, there’s more sugar in the mother’s blood. This excess sugar passes to the fetus, causing them to gain excess weight. Generally, a fetal weight of nine pounds (four kilograms) or more could cause complications for the mother and the baby. Here’s a brief overview of those complications (11)(12).
1. High blood pressure (HBP) and preeclampsia
HBP or hypertension during pregnancy can put undue stress on a mother’s circulatory system. As a result, she may develop preeclampsia, a condition where the mother’s organs, such as kidneys and liver, may not work properly. Some of the signs of preeclampsia an expecting mom may exhibit are:
- Proteinuria (protein in the urine)
- Vision changes
- Severe headaches
HBP and preeclampsia can increase the risk for preterm birth.
GD causes high maternal blood sugar levels, causing babies to gain more weight. Gaining too much weight (nine or more pounds) can cause the baby to get stuck in the birth canal. It can lead to birthing difficulties, such as a severe tear to the vagina or area between the vagina and anus (if it’s a vaginal delivery). Alternatively, in some cases, the mother may require a cesarean section (C-section).
3. Shoulder dystocia
It’s a birth injury/trauma where a baby’s shoulders get stuck inside the mother’s pelvis during labor and birth. It can lead to complications, such as prolonged labor and severe injuries to the mother and baby.
Shoulder dystocia could cause postpartum hemorrhage (excessive bleeding) in mothers. On the other hand, the babies could have collarbone and arm fractures. They may also experience damage in nerves responsible for giving sensation and movement to the hands, shoulders, and arms.
4. Perinatal depression
Perinatal depression is the depression that a mother could develop during or a year after pregnancy (postpartum depression). It affects up to 20 percent of new and pregnant moms (13). A mother with depression feels sad, apathetic, and irritable, making it difficult to bond with the baby. The condition may require treatment for the well-being of the mother and the baby.
5. Congenital disabilities
Babies born to diabetic mothers are more likely to have birth defects, affecting major organs and physiological systems, such as the heart, blood vessels, brain, spine, and digestive system. According to Stanford Children’s Health, birth defects usually occur in the first trimester of pregnancy and can be severe enough to cause stillbirth.
High maternal blood sugar levels make the baby’s sugar levels rise, compelling the baby’s body to make more insulin. However, the baby’s blood sugar levels fall after delivery. However, the insulin levels continue to stay high. As a result, the newborn’s blood glucose level falls too low, resulting in hypoglycemia.
7. Breathing problems
Too much sugar or insulin can hamper the baby’s intrauterine lung development. Underdeveloped lungs pose the risk of breathing problems, such as respiratory distress syndrome (RDS). Babies born before 37 weeks of pregnancy (preterm) are at a higher risk of developing breathing problems than those born after 37 weeks (full-term).
Yellow coloration of the skin and pupils of the eyes are common signs of jaundice. Babies born to mothers with gestational diabetes are more likely to develop jaundice than those born to mothers who don’t have GDM.
Besides these potential complications, the child is at risk of developing obesity and diabetes later in life.
Is Gestational Diabetes Preventable?
You can’t prevent gestational diabetes. But, you can reduce the chances of developing it by following healthy lifestyle practices, such as healthy eating and an active lifestyle before and during pregnancy. If you are planning to conceive and are overweight/obese, lose weight first by adopting healthy lifestyle habits.
On the other hand, if you are pregnant, don’t try losing weight. Instead, track your weight changes and keep them within the recommended target limits. For this, take the help of an expert, such as a nutritionist, to manage your weight. Remember, gaining too much weight too quickly can expose you to gestational diabetes risk.
Gestational diabetes is a condition when a non-diabetic pregnant woman develops high blood sugar levels. The exact cause for its development isn’t clear, but hormonal and weight changes during pregnancy play a role. Most women can manage gestational diabetes by following a healthy diet and active lifestyle habits. However, some may also need medication to ensure their sugar levels are under control.
- Gestational Diabetes and Pregnancy.
- Gestational Diabetes.
- Gestational Diabetes.
- Symptoms & Causes of Gestational Diabetes.
- Gestational Diabetes.
- Gestational Diabetes Mellitus (GDM)
- Gestational Diabetes.
- Tests & Diagnosis for Gestational Diabetes.
- How is gestational diabetes diagnosed?.
- Managing & Treating Gestational Diabetes.
- Gestational Diabetes.
- Diabetes During Pregnancy.
- Perinatal mental health.