Few newborn conditions generate greater controversy than neonatal hypoglycemia (low blood sugar), particularly when it occurs in breastfed infants. The ongoing debate is fueled by the fact that experts disagree not only on how to manage neonatal hypoglycemia (NH) but also on how to define it.
What is neonatal hypoglycemia?
Blood glucose (sugar) is the body’s source for energy. When blood glucose levels are low, a condition known as hypoglycemia occurs and the body is unable to function properly. Nearly all newborns experience hypoglycemia after birth. Blood glucose levels typically fall during the first 1–2 hours, dipping as low as 30 mg/dL (milligrams per dram liter), then rise over the next 12 hours (assuming babies are adequately fed), reaching levels of 45 mg/dL or more. These changes often occur without any medical intervention.
Although there is no evidence to show that a few hours of low blood sugar in asymptomatic (symptom-free) babies is harmful, many health care providers routinely screen newborns for hypoglycemia, including those with no signs of low blood sugar—signs include jitteriness, irritability, cyanosis (blue-gray discoloration of the skin), seizures, high pitched cry, poor feeding habits, weakness, exaggerated Moro (startle) reflex, and eye rolling.
Neonatal hypoglycemia can cause neurological damage in newborns if left untreated. Yet, routine screening has been widely criticized as costly, invasive, and unreliable. Moreover, it increases the risk of unnecessary supplementation in breastfed infants.
Screening for neonatal hypoglycemia
The American Academy of Pediatrics (AAP) recommends that screening for neonatal hypoglycemia be limited to at-risk infants (i.e., infants born to diabetic mothers; infants who are large or small for gestational age; late preterm infants born between 34–37 weeks), and infants who experience birth injury. The AAP also recommends that the frequency and duration of screening be based on the infant’s risk level. In other words, medical necessity (rather than policy or routine) should determine the need for NH screening and treatment.
A summary of the guidelines follow:
- Healthy full-term babies born to mothers with a normal pregnancy, labor, and birth do not need to be routinely screened for neonatal hypoglycemia.
- Babies at-risk for neonatal hypoglycemia include babies born to diabetic mothers, babies who are large or small for gestational age, and late preterm babies (those born between 34–37 weeks).
- The level of blood glucose at which treatment is recommended in asymptomatic babies is unclear.
- Blood glucose levels as low as 30 mg/dL in the first 1–2 hours after birth in asymptomatic babies may not be harmful.
- Blood glucose levels typically increase to 45 mg/dL by 12 hours after birth.
- Large and small for gestational age babies are considered at-risk for neonatal hypoglycemia for up to 10 days.
- Laboratory testing is the most accurate method of blood glucose measurement.
- Bedside test strips (versus a laboratory test) are unreliable measures of blood sugar and can yield results that vary by as much as 10–20 mg/dL.
- Babies who are symptomatic (indicative of blood glucose levels of less than 20–25 mg/dL) should have an immediate laboratory test for blood glucose and be given intravenous glucose if levels are below 40 mg/dL.
- Management of asymptomatic, at-risk babies varies with age.
Can babies with hypoglycemia breastfeed exclusively?
Exclusive breastfeeding is best for all babies, including those at greater risk for hypoglycemia. If a baby is symptomatic (showing signs of hypoglycemia) or has a blood glucose level less than 20–25 mg/dL, the baby should be given intravenous (IV) fluids until blood glucose levels are normal (greater than 45 mg/dL) and the baby is able to breastfeed effectively. Mothers of babies who are unable to breastfeed, even if just temporarily, can protect their milk supply by hand-expressing or pumping their breasts every 2–3 hours, or about 8 times a day, until their babies are able to resume breastfeeding. Mothers should be encouraged to practice skin-to-skin care, which can be done even while their baby is receiving IV fluids. (Read this to learn all the benefits of skin-to-skin care.)
Many babies experience neonatal hypoglycemia and most breastfeed exclusively. If your baby is unable to breastfeed and needs to be supplemented for a short time, you can either hand-express or pump your milk and feed it to your baby, or feed your baby donor milk or infant formula. Your baby’s health care provider can help you decide which option is best for you and your baby.