Neonatal Hyperglycemia: Everything You Should Know

Neonatal hyperglycemia is high blood sugar at birth. This condition usually resolves itself within the first few days of life, but high glucose levels could also be a sign of hormonal issues, infection, or neonatal diabetes.

Newborn babies can be born with vastly different blood sugar levels that will vary during the first few days after birth, usually before self-regulating.

However, sometimes newborn babies are born with neonatal hyperglycemia, which can present severe adverse health effects if it’s not regulated or treated shortly after birth.

This article describes everything you need to know about this type of hyperglycemia at birth, including symptoms and how new parents might go about treating this condition in their newborn.

Neonatal hyperglycemia is high blood sugar levels at birth. This is a less common condition than neonatal hypoglycemia, which is low blood sugar levels at birth.

Neonatal hyperglycemia is defined as either:

• serum glucose above 150 milligrams per deciliter (mg/dL) at birth
• whole blood glucose above 125 mg/dL at birth, irrespective of gestational age

It’s associated with both higher morbidity and mortality rates in neonates.

While sometimes a newborn’s body naturally corrects high blood sugar at birth within the first few days of life, it can last up to 10 days.

Other times, high blood sugar at birth can be a sign of an irregularity or something more serious.

What is neonatal diabetes?

When diabetes is diagnosed in the first 6 months after birth, it’s called monogenic or neonatal diabetes. This can be life threatening if not treated promptly.

This is an exceedingly rare form of diabetes and results from an inherited single-gene mutation. It affects only between 1% to 4% of all diabetes diagnoses.

Monogenic diabetes can be diagnosed on the fifth day of life through a genetic test, usually before symptom onset has reached its most serious peak.

Some cases of neonatal hyperglycemia are not neonatal diabetes and the baby’s body naturally corrects high blood sugar levels within the first few days of life.

You can read more about normal blood sugar range for newborns and at other points in life. Glucose ranges vary depending on many factors, including the type of diabetes you have, fasting or post-meal blood glucose ranges, pregnancy, hormonal changes, gender, and age.

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Oftentimes, the signs and symptoms of neonatal hyperglycemia at birth can be hard to distinguish because the baby is not on any sort of eating or sleeping schedule. Sometimes babies show no symptoms at all, but symptoms may include:

• sleeping more than usual
• frequent urination or constantly wet diapers
• dehydration
• thirst or hunger
• tiredness
• weight loss
• rapid breathing
• loss of consciousness

If you feel that something is wrong with your newborn, ask the nurse to check their blood glucose level to make sure it is within a healthy range, which for neonates is between 70 a n d 150 mg/dL .

Both undiagnosed neonatal diabetes and neonatal hyperglycemia can lead to serious complications like diabetic ketoacidosis (DKA), which can lead to neurological damage and even death if not treated.

A first sign of neonatal diabetes is slowed fetal growth followed by unusually low birthweight.

If you and your baby experienced either of these two conditions, make sure that the nurses test your baby’s blood glucose level multiple times before discharge to rule out neonatal diabetes.

Most parents are discharged from the hospital before a proper diagnosis can be made, so if you think your newborn is experiencing a health concern, get medical attention right away.

There can be many causes of neonatal hyperglycemia, including:

• prematurity and intrauterine growth restriction
• increased stress hormones
• causes related to enteral feeding
• hormonal issues
• liver problems
• causes related to total parenteral nutrition (TPN)
• sepsis or other infection
• iatrogenic
• transient neonatal diabetes mellitus, which resolves on its own within 1 to 18 months
• monogenic diabetes mellitus, which is caused by a single-gene mutation
• drugs or prescription medications taken by the mother during pregnancy

Sometimes no treatment is needed, and the high blood glucose levels fall within range on their own within a few days.

Depending on the severity, neonatal hyperglycemia may require treatment in the neonatal intensive care unit (NICU).

Treatment may include:

Starting insulin therapy

Immediately starting neonates on insulin therapy is still controversial and should only be considered if the blood glucose level is at or above 250 mg/dL and if the urine glucose is more than 2+ in two different measures, 4 or more hours apart.

Often, insulin therapy is administered via continuous subcutaneous insulin injection (CSII), which allows the insulin to be dosed more precisely to better manage blood sugar levels.

Reducing dextrose

Limiting the amount of dextrose, a type of sugar given to infants in the first few days of life. Dextrose is commonly given to neonates to help regulate low blood sugar after birth.

Genetic testing

Clinicians recommend that infants with neonatal hyperglycemia go through genetic testing for neonatal diabetes, even if those higher blood sugars resolve on their own.

Overly treating neonatal hyperglycemia with insulin increases the risk of hypoglycemia, which can increase the risk of severe adverse health effects, including death if not treated promptly.

Neonatal hyperglycemia is high blood sugar at birth. This condition is less common than neonatal hypoglycemia and is defined as either serum glucose of more than 150 mg/dL at birth or whole blood glucose of more than 125 mg/dL at birth. It usually clears up within a few days.

However, this may be a sign of either an irregularity, infection, or even neonatal diabetes. These conditions can be fatal if not treated quickly. If your baby’s blood glucose level is high at birth, they will monitor for other abnormalities to rule out conditions like sepsis, a liver problem, or monogenic diabetes.

Last medically reviewed on April 10, 2023