nutritional management of gestational diabetes

By Belinda Harvie, Naturopath and Nutritionist

Gestational diabetes (GD) is a transient form of diabetes identified during pregnancy. To treat GD, we must first understand the physiological process underlying the condition. Normally when we metabolise carbohydrates, glucose is formed and is transported through the bloodstream. In response to this rise in blood glucose, the pancreas produces the hormone insulin which induces the cells to uptake glucose from the blood to be utilised for energy.

 During pregnancy, the placenta which provides the baby with, blood, oxygen and nutrients, also produces various hormones that work to maintain the pregnancy. These placental hormones may also have a counter effect on insulin. This most often occurs around 20- 24 weeks gestation and intensifies as the placenta continues to grow. In most cases the pancreas is able to compensate for the hormonal response by secreting more insulin. However, in some women, the pancreas is unable to adjust to the overwhelm of placental hormones and the cells may become unresponsive to insulin resulting in a build-up of glucose in the blood. GD refers to these high levels of blood glucose (hyperglycaemia) during pregnancy.

Most women with GD will be asymptomatic however some may experience polydipsia (extreme thirst), polyphagia (extreme hunger), polyuria (excessive urine output), symptoms which many women may experience without having GD.

Any woman can develop GD however risk factors include:

·      Previous GD

·      Overweight/obesity

·      Prediabetes (elevated blood sugar levels)

·      Insulin resistance prior to or  in early pregnancy

·      Ethnicity: Aboriginal, Indian, Pacific Islander, Maori, non-Caucasian African, South and South East Asian

·      Previous macrosomia (birth weight of baby >4500g)

·      Polycystic ovarian syndrome (PCOS)

·      Certain medications e.g., corticosteroids

The gold standard test for GD is the routine Oral Glucose Tolerance Test (OGTT), recommended at 24-28 weeks’ gestation. You will be required to fast for 8-10 hours so this test is best done first thing in the morning. A fasting blood sample is collected, after which you will be required to drink a 75g glucose drink within five minutes. Blood samples are collected at one and again at two hours post consumption to measure your body’s response to glucose and how well your body can clear the glucose from the blood.

Although this is the most routine testing method for GD, it is not the only method. How quickly the body clears glucose from the bloodstream is related to how frequently a woman eats high carbohydrate or high-sugar foods. The GTT may be inaccurate if you eat a low-carb diet prior to the test. In fact this has been documented since the 1960’s (Felig, Philip & Lynch, 1970). Another option therefore may be Home Glucose Monitoring which involves using blood sugar test strips to check your blood sugar four times per day, for approximately two weeks. Testing for GD is an individual choice and needs to be discussed with a woman’s healthcare providers.

Women at high risk of developing GD may be screened earlier and more often. A HbA1c, may be taken in the first trimester to measure the average blood glucose over the previous 8-12 weeks. It should be noted that if your Hba1c test is negative in the first trimester, this does not put you in the clear for developing GD in later pregnancy. It is recommended that women diagnosed with GD are tested using the OGTT test 6-12 weeks postpartum and every 1-2 years ongoing after birth to ensure blood glucose levels are within range.

GD left unmanaged may impact the health of both the mother and baby and place them at risk of developing type II diabetes later in life. GD may cause a rise in blood pressure in the mother placing her at risk of preeclampsia and preterm birth. Additionally, the high glucose levels in the mother’s blood is passed onto the baby which may cause the baby to grow large complicating the birth process. The high levels of glucose now in the baby stimulates the baby’s pancreas to produce more insulin than normal. Upon delivery the baby is no longer being shunted glucose by the mother however continues to produce high amounts of insulin causing the baby to have a sudden drop in blood glucose (neonatal hypoglycaemia).  Exceedingly low blood glucose levels in a baby may cause problems breathing and feeding, floppiness, irritability, tremors or seizures. The newborns blood sugar levels will be monitored and corrected with prompt feeding or if necessary intravenous glucose.

Being diagnosed with GD is not the be all end all. This simply gives you information you need to manage your blood glucose levels to ensure the health of you and your baby. The medical management of GD in the first instance includes dietetic and lifestyle advice. Should blood glucose levels remain above glycaemic targets with diet and lifestyle changes, pharmaceutical agents or subcutaneous insulin are prescribed.A more thorough and holistic approach can also be taken, and this is what we are passionate about at Maia Mothers. Naturopathic/Nutritional management of GD includes individualised dietary recommendations, lifestyle changes including stress management, sleep regulation and exercise alongside nutritional supplementation and/or herbal medicine where needed to reduce inflammation, support nervous, digestive, liver and pancreatic function.

At Maia Mothers we take a preventative approach whereby maternal health is optimised with preconception care and ongoing pregnancy and postnatal support.

References

Felig, Pilip, and Vincennt Lynch. “Starvation in human pregnancy: hypoglycemia, hypoinsulinemia, and hyperketonemia.” Science 170.3961 (1970): 990-992.