What is the significance of ketonuria in pregnant women?

From the Guidelines

Ketones in the urine of pregnant women should be monitored and addressed promptly to prevent potential complications, as recommended by the most recent guidelines 1.

Importance of Monitoring Ketones

Ketones appear in the urine when the body breaks down fat for energy instead of using glucose, which can happen due to inadequate caloric intake, severe morning sickness, or poorly controlled diabetes.

• The presence of ketones may signal nutritional issues that could affect both the mother and the baby if left unaddressed.
• Monitoring ketones is crucial, especially for women with diabetes, those experiencing significant vomiting, or those who have lost weight during pregnancy.

Prevention and Management

To prevent ketones, it is essential to:

• Eat small, frequent meals throughout the day
• Stay well-hydrated
• Not skip meals
• Include a balance of protein, healthy fats, and complex carbohydrates in the diet
• If experiencing morning sickness, try to eat something small like crackers before getting out of bed

Recommendations for Healthcare Providers

Healthcare providers might recommend:

• Increasing caloric intake
• In severe cases, IV fluids and anti-nausea medication if ketones are detected alongside significant symptoms
• Prescribing ketone strips and educating patients on diabetic ketoacidosis (DKA) prevention and detection, especially for women with type 1 diabetes 1
• Regular monitoring of blood pressure and urine protein to detect hypertensive disorders, and increased surveillance for pregnancies at risk for fetal demise 1

From the Research

Ketone in Urine for Pregnant Women

• Ketones in urine can be an indicator of diabetic ketoacidosis (DKA) in pregnant women, which is a life-threatening emergency for both the mother and the fetus 2.
• Fasting ketonuria is common during normal pregnancy, and its prevalence is increased among pregnant women with Gestational Diabetes Mellitus (GDM) who are on a diet 3.
• The presence of ketonemia is significantly lower than the presence of ketonuria in women with GDM, and weight loss per week is the only independent factor found to be associated with increased levels of 3HB 3.
• Current dietary advice for women with GDM is to avoid diets that result in elevated ketone levels, due to concerns that maternal ketones are associated with poor fetal and childhood outcomes 4.
• However, the evidence behind these guidelines is conflicting and inconsistent, and further research is needed to understand the relationship between maternal ketones and fetal and childhood outcomes 4.

Measurement of Ketones

• The use of capillary blood 3-β-hydroxybutyrate (3HB) is a more precise method than urine ketones measurement for the diagnosis of DKA 3.
• Point-of-care tests are available for self-testing of blood ketones and urine ketones through measurement of beta-hydroxybutyrate and acetoacetate, and are cleared by the US Food and Drug Administration (FDA) 5.
• Measurement of ketones can be helpful to assess compliance with low carbohydrate diets, assessment of acidosis associated with alcohol use, and to identify DKA due to insulin deficiency 5.

Pregnancy and Ketones

• DKA in pregnancy may be euglycemic, and prevention, early recognition, immediate hospitalization, and aggressive management remain the cornerstones in DKA management in pregnancy 2.
• A substantial proportion of metabolic abnormalities in GDM women are not detected with a monitoring program that measures only fasting ketonuria and postprandial CBG after main meals 6.
• Ketonuria was significant in 22.5% of the time points and 41.2% of women had significant ketonuria at one or more time points, highlighting the importance of regular monitoring 6.