What are ketones?
Ketones are an acid remaining when the body burns its own fat. When the body has insufficient insulin (or cannot use sufficient insulin), it cannot get glucose (sugar) from the blood into the body's cells to use as energy and will instead begin to burn fat stores. When the body is burning too much fat, it may cause ketones to become present as by product shown in your urine. Burning fat instead of glucose can lead to a condition called ketosis. It can make you feel poorly, with lack of energy. If you have healthy or low BMI it can also be dangerous as you may also lose too much weight.
Testing for ketones
Your urine is usually tested for ketones during your diabetes clinic appointments. You may also be tested for ketones if you have been taken into hospital with high blood sugar levels.
Ketones are detected by testing the urine with a dip stick. They are measured on a scale with 0 being lowest and 4++ being the highest. The test sticks can be purchased from a pharmacy or online and in some cases you may be prescribed test strips for home testing for if you get blood sugar levels over a certain level. Your diabetes midwife will usually complete ketone tests when you attend clinic appointments, so it is not necessary to purchase dip sticks for home use unless you're advised to by a medical professional. Blood ketones can also be tested and are much more accurate than the urine dip sticks. Type 1 diabetics may be given ketone blood testing monitors.
Why are ketones common in ladies diagnosed with gestational diabetes?
Ketones can be detected when you have not eaten for a long period of time and may be found in samples taken in the morning due to fasting overnight. It is common for mothers with gestational diabetes to develop ketones due to limiting too many carbohydrates from the diet, by not eating enough in general, or being dehydrated. Once on a GD diet many ladies worry about what foods to eat and may avoid eating, or knowing that carbs cause raises in blood glucose levels, they cut them out of the diet or limit them too severely as a way of controlling blood glucose levels.
What can I do if I get told I have ketones in my urine sample?
If ketones become present in urine then you could try to increase the amount of fluids and carbs in your diet. In severe cases you may be admitted to hospital for intravenous fluids and a sliding scale (insulin and glucose drip), but this is rare. Your medical professional will advise if their is any concern over the amount of ketones present and often trace amounts may be shown. Discuss any concerns with your healthcare professional.
Increasing carbs v's higher blood sugar levels
It is important to find a balance between good blood glucose management and prevention of ketosis. If you cannot eat sufficient carbohydrates to prevent ketones then medication and/or insulin may be introduced or doses increased to allow you to eat sufficient amounts.
Other common causes of ketones in pregnancy
- Hyperemesis Gravidarum (HG or severe sickness in pregnancy)
- Morning sickness
- Poor blood glucose management
- Not eating for long periods of time
- When the diet is low in carbohydrates, exercise levels are high or a combination of both
- In pregnant women with diabetes and in gestational diabetes
- When blood sugars are high (over 15 mmol/L)
- In DKA with suspected ketoacidosis
If you have concerns regarding ketones in your urine sample following your clinic appointment then please discuss these with your diabetes health care professionals
NICE guidelines around ketones in gestational diabetes
Ketone testing and diabetic ketoacidosis
1.3.21 Advise pregnant women with type 2 diabetes or gestational diabetes to seek urgent medical advice if they become hyperglycaemic or unwell. [new 2015]
1.3.22 Test urgently for ketonaemia if a pregnant woman with any form of diabetes presents with hyperglycaemia or is unwell, to exclude diabetic ketoacidosis. [new 2015]
1.3.23 During pregnancy, admit immediately women who are suspected of having diabetic ketoacidosis for level 2 critical care, where they can receive both medical and obstetric care. 
What is diabetic ketoacidosis (DKA)?
When blood sugar levels remain consistently high (hyperglycaemia) this can lead to a condition called diabetic ketoacidosis (DKA). When there is a severe lack of insulin, the body cannot process glucose which is what it uses for energy. The body then starts to break down other body tissue (fat) to create an alternative source of energy. Ketones are the by-product of this process. Ketones are poisonous acidic chemicals which build up, hence the name 'acidosis'.
DKA is a life threatening emergency and anyone who is depending on insulin can develop DKA. Although very rare in those diagnosed with gestational diabetes, it is still something that we should be aware of. Missed doses of insulin, excessive exercise and illness can all be causes of DKA.
Symptoms of DKA:
- High blood glucose levels (over 15mmol/L)
- Ketones in the urine and blood
- Frequently passing urine
- Feeling tired and lethargic
- Blurry vision
- Abdominal pain, nausea, vomiting
- Struggling to catch breath
- Smell of pear drops on the breath
If you have any concerns over DKA or are worried as you are experiencing any of the above symptoms, then please seek medical advice by calling your hospital, or 111 out of hours for advice. If situations arise where you collapse or there is the smell of pear drops on your breath then 999 should be called immediately for medical assistance