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Gestational Diabetes

Gestational diabetes definitely requires additional attention during pregnancy, but the right attention, care, and support can keep Mom and baby healthy throughout. Read on to learn more about gestational diabetes. For more information on recommended diet, exercise, or gestational diabetes in general, see the Other Resources section below.

Starting Point: Gestational Diabetes Basics

What is gestational diabetes?

Gestational diabetes affects some pregnant women. The term itself can actually be a little misleading, according to Dr. Lois Jovanovič, because it implies that the diabetes symptoms are only confined to pregnancy. However, it is possible to uncover a diagnosis of type 1 or type 2 diabetes after pregnancy if the mother’s blood sugar levels remain elevated. A more accurate descriptor, she says, would be “hyperglycemia during pregnancy.” (Hyperglycemia refers to elevated blood glucose levels; for the purposes of this resource, we use the more commonly recognized “gestational diabetes.”) Each year, up to 14% of pregnant women in the US develop this condition. It can occur in pregnant women who have never had diabetes before and in whom elevated blood glucose is first detected during pregnancy. Gestational diabetes is different from being diagnosed with type 1 or type 2 diabetes before pregnancy. It often develops in the later stages of pregnancy, usually disappearing after giving birth. During pregnancy, insulin (the hormone that helps the body use glucose for energy) may be hindered from performing its typical role due to interference from hormones produced by the fetus or other chemical changes within the body; usually additional insulin will be produced to compensate. In a woman with gestational diabetes, insulin is unable to keep blood glucose concentrations in target range, resulting in heightened blood glucose levels and associated health risks for mom and baby.

How and when is gestational diabetes diagnosed?

Pregnant women are usually tested for gestational diabetes between weeks 24 and 28 of pregnancy. Healthcare professionals will use one of the following methods for diagnosis:

  1. Two-part test: This method is regularly used in the US. The pregnant woman will consume a sugary drink, followed by measurement of blood glucose an hour later. If this yields a blood sugar level higher than 200 mg/dl (for reference, 70-120 mg/dl is the target range), a second evaluation, an oral glucose tolerance test (GTT), will most likely be ordered. The GTT will measure blood glucose levels without food (fasting) as well as one, two, and three hours after eating. Gestational diabetes is diagnosed only if the GTT reveals two or more elevated blood glucose results.
  2. One-part test: With this method, fasting blood glucose levels will be measured, as well as one and two hours post-consumption of a sugary drink. Gestational diabetes is diagnosed only if one or more blood sugar measurements are higher than normal.

Can gestational diabetes be prevented?

While gestational diabetes can’t be completely prevented, it is possible to lower the chances of developing it by consuming a healthy diet, losing excess weight, and exercising regularly – both before and during pregnancy [Editor’s note: Individuals should check with their healthcare professional about what to eat and how much to exercise]. It is also important to note that many women develop gestational diabetes – it results from a combination of factors, many of which are beyond any individual’s control.

Who is at risk of developing gestational diabetes?

Risk factors for developing gestational diabetes include:

  • Aged 25 and over

  • Related health history: Prior or current conditions that may increase risk include (but are not limited to) having prediabetes, a family member with type 2 diabetes, gestational diabetes in past pregnancies, an unexplained stillbirth, or a previous newborn weighing over nine pounds.

  • Polycystic Ovarian Syndrome (PCOS): This is a hormone disorder that primarily affects the ovaries. It affects 5-10% of women of childbearing age and seems to result partially because of genetics.

  • Being of a non-European race: Depending on your ethnicity, you may have a higher chance of developing gestational diabetes.

  • Being obese (defined by a BMI of 30 or more)

  • High or low birth weight: If the mother at her own birth weighed less than 5 pounds 8 ounces or more than 8 pounds 13 ounces, she will have a higher risk of developing gestational diabetes.

It is possible to have none of these risk factors and still develop gestational diabetes or vice versa. Speak with a healthcare professional about appropriate screening and healthy pregnancy behaviors. 

What are the symptoms of gestational diabetes?

Gestational diabetes may not have noticeable signs. However, some women may experience:

  • Increased urination

  • Thirst

  • Hunger

  • Blurred vision

What should a woman diagnosed with gestational diabetes do?

Work alongside a healthcare professional early and often after diagnosis to start managing blood glucose levels. Treatments will almost always include strategic meal plans and exercise and can also benefit from inclusion of an array of available diabetes technologies.

The California Department of Public Health, for example, recommends a carbohydrate-controlled diet with meals and snacks spread 2-3 hours apart. Additionally, healthcare providers recommend 30-60 minutes of moderately intense cardio and strength training three times a week. Treatment could also include insulin and consistent monitoring of blood glucose levels with a continuous glucose monitor (CGM). While it is very important to monitor and manage blood sugar, keep in mind that there are several other factors that affect blood glucose, including sleep, environment, etc. Talk to a healthcare professional – physicians, nurses, diabetes educators are all great! – to devise an individual approach, which may include meal plans, exercise routines, and insulin (if necessary).

Talk to a healthcare professional about available learning tools and technologies that may be able to assist in blood glucose management. A continuous glucose monitor (CGM), for example, tracks blood glucose levels at five minute intervals throughout the day and night. Since it is critical for a developing baby’s health that the mother remain in target blood glucose range (the ADA suggests 95-140 mg/dl) for as much time as possible, continued updates and awareness about blood glucose trends can be exceptionally helpful for tracking and replicating the factors that create the best environment for mother and child.

What effects does gestational diabetes have during pregnancy?

With appropriate care and caution, gestational diabetes need not negatively impact the health of mother or child. It is important to learn about the condition and take appropriate action, in partnership with healthcare professionals, to manage blood glucose levels during and after pregnancy.

Gestational diabetes, if left untreated, can lead to various issues during pregnancy, such as:

  • Giving birth to a large baby (weighing more than nine pounds), increasing the risk of injury during birth to both the baby and the mother. The chances of requiring a Caesarean section also increase at high birth weights.

  • Increased risk of miscarriage and birth defects. Although stillbirths are becoming rarer as medical technologies advance, gestational diabetes remains a factor associated with increased risk.

  • High blood pressure, which may be detrimental to long- and short-term health.

  • Preeclampsia, a rare complication (occurring in about 5-8% of pregnant women), characterized by high blood pressure. It may result in premature birth, or in rare instances, stillbirth. Contact a healthcare professional right away if preeclampsia is suspected (find more information about signs and symptoms here).

What effects does gestational diabetes have after pregnancy?

  • Type 1 and type 2 diabetes: Sometimes, a woman will have type 1 or type 2 diabetes but not know it, and the diagnosis of gestational diabetes unknowingly reveals this preexisting condition. If blood glucose levels remain high even after giving birth, a different diabetes diagnosis is likely. Talk to a healthcare professional about appropriate screening and follow-up.

  • Increased likelihood of developing type 2 diabetes: Studies have shown that within 10 years of giving birth, 35-60% of women who had gestational diabetes will develop type 2 diabetes. However risk can be reduced with an appropriate treatment plan, often including strategic healthy diet and exercise, and sometimes medications, too. 

How may gestational diabetes affect the baby?

Nutrients from a mother’s bloodstream help fuel the baby’s growth during pregnancy. In cases of gestational diabetes, a mother’s high blood glucose can cause the baby to absorb more glucose than it needs. Excess glucose can lead to storage of additional fat, which can in turn lead to complications at birth and later in life. Other effects could include:

  • “Baby Fat”: The baby is more likely to be heavier than average (weighing more than 9 pounds). This extra weight could cause shoulder damage during birth.

  • Low birth weight, low blood glucose levels, breathing problems: During pregnancy, the baby does not receive any of the insulin produced by the mother. As a result, the growing baby produces extra insulin on its own to combat the extra inflow of glucose. Due to excess insulin at the time of birth, the baby has a higher risk of having low blood glucose as a newborn. This condition is called neonatal hypoglycemia.

  • Higher risk of childhood obesity

  • Higher risk of developing type 2 diabetes as an adult

Does gestational diabetes affect future pregnancies?

Two out of three women diagnosed with gestational diabetes will be diagnosed again in future pregnancies; the more pregnancies a woman has with elevated blood glucose levels, the more likely future pregnancies will bring about similar blood glucose trends.

Risk can be reduced through healthy eating habits and regular exercise. For example, studies have shown that obese women who lost more than 10 pounds between their first and second pregnancies lowered their risk for gestational diabetes. On the other hand, obese women who gained more than 10 pounds between their first and second pregnancies significantly increased their risk for developing gestational diabetes in their next pregnancy.

What can be done to promote the baby’s health?

It is especially important to focus on the baby’s health from an early age (this applies to all babies!) since it is likely the child will carry a higher risk of childhood obesity and type 2 diabetes as an adult if born to a mother with heightened blood glucose. The NIH has many resources for raising healthy children in both English and Spanish. Maintaining a healthy lifestyle before and during pregnancy is encouraged! Good tips for both mother and child include:

  • Setting a good example of healthy behaviors for children by maintaining a balanced diet. While a mother’s diet less directly affects her child’s health after birth, healthy habits can last a lifetime.

  • Keep the kitchen stocked with lots of fruits and vegetables, whole grains, low-fat or fat-free dairy, protein, with little to no processed food.

  • Regular exercise as recommended by the NIH.

  • Adequate sleep and general promotion of wellness, including stress management.

  • Establishing and encouraging healthy lifestyle patterns during childhood.

Other Resources

- Katherine Gao and Sabrina Lin