Neonatal hypoglycemia occurs when a newborn’s blood sugar (glucose) drops below the concentration needed to support normal physiological functions. Glucose is the primary energy source for the brain, and the developing brain of a newborn has a particularly high demand for it. When levels are too low, the condition is called neuroglycopenia, which can rapidly lead to brain cell injury. This metabolic disturbance is the most common one seen in newborns and requires prompt action to prevent potential long-term developmental issues. The goal of treatment is to stabilize the infant’s glucose supply to protect neurological health.
Recognizing the Symptoms of Low Blood Sugar
Identifying low blood sugar in a newborn can be challenging because initial signs are often subtle or mimic normal newborn behavior. Caregivers should watch for increased jitteriness, which presents as tremors or shakiness that may be suppressible by touch. Another common sign is lethargy, where the baby appears sleepy, listless, or has a floppy muscle tone (hypotonia).
Behavioral changes also include poor feeding, such as refusing to latch or sucking weakly, or having a weak or high-pitched cry. Subtle physical signs can involve a low body temperature (hypothermia) or excessive sweating.
In more serious instances, the signs indicate severe neuroglycopenia. These severe symptoms include pauses in breathing (apnea), rapid breathing, a blue tinge to the skin and lips (cyanosis), or seizures. Any observation of these severe signs requires immediate emergency medical attention, as they indicate a lack of glucose reaching the brain.
Immediate First Steps for Caregivers
If a newborn is exhibiting signs of low blood sugar, the immediate step is to initiate or increase feeding to deliver an oral source of glucose. Breast milk or formula are the primary sources of sugar and should be offered right away, even if the baby takes small amounts. If the baby is too sleepy or weak to feed directly, expressed colostrum or milk can be given via a syringe or small cup.
Another effective first step is to place the baby in continuous skin-to-skin contact with a parent or caregiver. This practice helps regulate the newborn’s body temperature, which is linked to glucose metabolism. Keeping the baby warm reduces the energy expenditure needed to maintain temperature, preserving limited glucose stores.
In a hospital setting, or if advised by a medical professional, an oral dextrose gel may be administered as a fast-acting glucose source rubbed into the cheek pouch. Caregivers should seek professional medical help promptly, especially if the baby is symptomatic or refuses to feed. If the infant is showing severe symptoms like seizures or apnea, emergency services must be contacted immediately, as these situations require rapid intervention.
Clinical Treatment and Medical Intervention
Once a newborn with hypoglycemia is under medical care, the treatment strategy depends on the severity of the low glucose level and the presence of symptoms. Diagnostic confirmation is performed using a blood sample, ideally measured by a laboratory, as point-of-care glucometers can be less accurate at low concentrations. The treatment goal is to maintain blood glucose levels at or above a safe threshold, generally set at 45 mg/dL (2.5 mmol/L) or higher.
For infants with asymptomatic low blood sugar, the first line of treatment is increased feeding combined with a 40% dextrose gel applied to the buccal mucosa. This sugar-rich gel is absorbed through the lining of the mouth and provides a rapid glucose boost to stabilize levels. If glucose levels do not respond to oral feeding and dextrose gel, or if the infant is severely symptomatic, treatment is immediately escalated.
The definitive medical intervention involves administering intravenous (IV) dextrose, a sugar-water solution, directly into the bloodstream. This is often started with a quick glucose bolus, such as 2.5 mL/kg of 10% dextrose, followed by a continuous infusion to stabilize the glucose supply. This level of care requires continuous monitoring of blood glucose and vital signs, often necessitating admission to a Neonatal Intensive Care Unit (NICU) or a special care nursery.
Managing Ongoing Risk and Monitoring
Certain newborns are at a significantly higher risk for developing low blood sugar due to limitations in glucose production or storage. High-risk infants include those born prematurely (late-preterm), those who are small or large for gestational age, and those born to mothers with poorly controlled diabetes. These infants are highly susceptible because of the excess insulin their bodies may still be producing.
For these at-risk babies, systematic glucose screening is performed shortly after birth and before scheduled feeds, even if the baby shows no symptoms. Monitoring typically continues until the infant can maintain stable glucose levels for 12 to 24 hours while exclusively on oral feeds. The primary strategy for preventing recurrent episodes is the promotion of frequent and adequate feeding, ideally every three hours or whenever the baby shows feeding cues.
For infants whose hypoglycemia persists beyond the first few days, further investigation is undertaken to identify an underlying cause, such as a hormonal or metabolic disorder. Before discharge, these infants may undergo a monitored fast to ensure they can sustain healthy glucose levels between feeds. Long-term management may involve specialized follow-up, and in rare cases, specific medications or home glucose monitoring may be necessary.