Neonatal hypoglycemia
After the cord is clamped, the maternal glucose supply stops. Glucose normally falls to a low point in the first 1–2 hours and then rises as the infant mobilizes glycogen, starts gluconeogenesis, and feeds. This transitional dip is expected. Hypoglycemia becomes harmful when it is severe, prolonged, recurrent, or symptomatic, because the newborn brain depends on glucose; injury can cause seizures and long-term developmental problems. No single glucose value separates safe from harmful, so guidelines use operational thresholds for action.
Mechanisms and at-risk infants
| Mechanism | Examples |
|---|
| Excess insulin (hyperinsulinism) | Infant of a diabetic mother (IDM), LGA, Beckwith–Wiedemann syndrome, maternal IV dextrose in labor |
| Low glycogen stores | Preterm and late preterm, SGA/growth-restricted, post-term |
| Increased glucose use | Cold stress, sepsis, respiratory distress, perinatal asphyxia, polycythemia |
| Impaired production | Inborn errors of metabolism, adrenal insufficiency, hypopituitarism |
Hyperthyroidism is not a typical cause of neonatal hypoglycemia.
Neonatal sepsis
A systemic infection in the first month of life. Newborns have immature neutrophil function, low immunoglobulin levels (especially if preterm, since most maternal IgG crosses after 32 weeks), and thin skin and mucosal barriers.
| Feature | Early-onset sepsis (EOS) | Late-onset sepsis (LOS) |
|---|
| Timing | Within the first 72 hours (some definitions use 7 days) | After 72 hours (to about 90 days in NICU infants) |
| Source | Vertical — ascending infection or passage through the birth canal | Hospital or community — central lines, ventilators, procedures, caregivers' hands |
| Main organisms | Group B Streptococcus (GBS) (most common in term infants), E. coli (leading cause in very preterm infants), Listeria | Coagulase-negative staphylococci, S. aureus, gram-negative bacilli, Candida |
| Risk factors | Maternal GBS colonization without adequate intrapartum antibiotics, intraamniotic infection (chorioamnionitis), prolonged rupture of membranes (18 hours or more), maternal fever, preterm birth | Prematurity, central lines, mechanical ventilation, prolonged NICU stay, delayed enteral feeding |
Hypoglycemia — signs are nonspecific; many infants have no signs at all.
- Jitteriness/tremors, irritability, exaggerated Moro reflex
- Poor feeding, lethargy, hypotonia, weak or high-pitched cry
- Tachypnea, apnea, cyanosis, hypothermia, sweating
- Seizures, coma (severe)
Distinguish jitteriness from seizure: jitteriness stops when the limb is held and is provoked by stimulation; seizures are not stopped by restraint and may include eye deviation or lip smacking.
Sepsis — also subtle and nonspecific:
- Temperature instability — hypothermia is more common than fever, especially in preterm infants
- Poor feeding, lethargy, "not acting right," hypotonia
- Respiratory distress (tachypnea, grunting, nasal flaring, retractions), apnea
- Tachycardia or bradycardia, poor perfusion (capillary refill more than 3 seconds, mottling), hypotension (late, septic shock)
- Glucose instability (hypo- or hyperglycemia), jaundice, abdominal distension, vomiting, petechiae
- Meningitis: bulging fontanel, seizures, irritability
Glucose screening (AAP 2011 algorithm for at-risk infants 34 weeks or more)
- Screen late preterm, SGA, LGA, and IDM infants; healthy term AGA infants without risk factors or signs are not routinely screened.
- Feed within the first hour; check the first glucose about 30 minutes after the first feed; continue checks before feeds.
- Duration: IDM and LGA (34 weeks or more) for about 12 hours; late preterm and SGA for about 24 hours if values remain acceptable.
- Point-of-care meters are less accurate at low values: send a laboratory plasma glucose to confirm, but do not delay treatment while waiting.
Heel-stick technique: warm the heel, clean with alcohol and let it dry completely, puncture the lateral or medial plantar surface of the heel with a newborn safety lancet (avoid the back of the heel and the central sole — risk of bone injury), wipe away the first drop, avoid heavy squeezing (hemolysis, tissue fluid).
Sepsis evaluation
| Test | Key points |
|---|
| Blood culture | Obtain before the first antibiotic dose; adequate volume (at least 1 mL) improves detection |
| Lumbar puncture (CSF) | If culture is positive, signs of meningitis, or the infant is very ill (when stable enough) |
| Urine culture (catheter or suprapubic) | For late-onset evaluation, not routine in EOS |
| CBC with differential | Neutropenia, high immature-to-total neutrophil ratio, thrombocytopenia support sepsis |
| C-reactive protein, procalcitonin | Serial values help decide when to stop antibiotics; poor at ruling sepsis in |
| Glucose, blood gas, lactate | Metabolic acidosis and hypoperfusion |
For infants born at 34–35 weeks or more, many centers use the multivariate (Kaiser) EOS risk calculator (maternal risk factors plus the infant's clinical status) to decide between observation, testing, or empiric antibiotics.
Hypoglycemia — AAP 2011 operational thresholds (asymptomatic at-risk infants)
| Age | Action threshold | Response |
|---|
| Birth to 4 hours | Below 25 mg/dL (1.4 mmol/L) | Feed and recheck in 1 hour; if still below 25 mg/dL (1.4 mmol/L) → IV glucose; 25–40 mg/dL (1.4–2.2 mmol/L) → refeed or IV glucose as needed |
| 4 to 24 hours | Below 35 mg/dL (1.9 mmol/L) | Feed and recheck in 1 hour; if still below 35 mg/dL (1.9 mmol/L) → IV glucose; 35–45 mg/dL (1.9–2.5 mmol/L) → refeed or IV glucose as needed |
- Target 45 mg/dL (2.5 mmol/L) or more before routine feeds.
- Symptomatic infants with glucose below 40 mg/dL (2.2 mmol/L) receive IV glucose.
- The Pediatric Endocrine Society (2015) recommends higher goals for high-risk infants — above 50 mg/dL (2.8 mmol/L) in the first 48 hours and above 60 mg/dL (3.3 mmol/L) after 48 hours — and evaluation for a persistent disorder if low values continue beyond 48 hours.
Treatment options
- Feeding (breast milk preferred; expressed milk or formula supplementation as ordered).
- Oral (buccal) 40% dextrose gel 200 mg/kg (0.5 mL/kg), massaged into the inner cheek, followed by a feed; recheck glucose. Used in many units for asymptomatic late preterm and term infants in the first 48 hours; it reduces NICU admission and supports breastfeeding.
- IV dextrose: a mini-bolus of D10W 2 mL/kg (200 mg/kg) given slowly over several minutes, then a continuous infusion (commonly D10W at 80–100 mL/kg/day, about 5.5–7 mg/kg/min of glucose). Never give concentrated dextrose (D25/D50) to newborns — vein injury and rebound hyperinsulinemia. Peripheral lines generally tolerate up to 12.5% dextrose; higher concentrations need a central line. Wean slowly while monitoring glucose; watch for infiltration, fluid overload, and hyperglycemia.
- Persistent hypoglycemia: evaluation for hyperinsulinism or endocrine and metabolic causes; medications such as glucagon or diazoxide are specialist decisions (glucagon: vomiting, requires glycogen stores; diazoxide: fluid retention, pulmonary hypertension).
Sepsis
- Empiric antibiotics immediately after cultures — do not delay for results.
- EOS: ampicillin + gentamicin.
- LOS: regimens usually add coverage for staphylococci (e.g., vancomycin) with an aminoglycoside or a cephalosporin, per local resistance patterns. Suspected meningitis may require a third- or fourth-generation cephalosporin; acyclovir is added if neonatal herpes simplex is possible.
- Stop antibiotics at 36–48 hours if cultures are negative and the infant is well; treat culture-proven sepsis for the full course (longer for meningitis).
- Supportive care: oxygen and ventilation, isotonic fluid boluses (commonly 10 mL/kg) for poor perfusion, vasoactive drugs for shock, glucose and temperature control, remove or replace infected central lines.
Antibiotic safety (all neonatal doses are weight-, gestational-age-, and postnatal-age-based and are verified against a neonatal drug reference in practice)
| Drug | Key safety points |
|---|
| Ampicillin | Hypersensitivity (rash, rarely anaphylaxis); high doses can cause seizures in renal impairment; dosing interval varies with gestational and postnatal age |
| Gentamicin | Nephrotoxicity and ototoxicity; monitor serum levels (trough, and peak when ordered) and urine output/creatinine; extended-interval dosing by gestational and postnatal age; flush lines between gentamicin and ampicillin — they are incompatible in the same line |
| Vancomycin | Nephrotoxicity; infuse over at least 60 minutes to prevent vancomycin infusion reaction (flushing, hypotension); monitor levels |
| Cephalosporins | Ceftriaxone is avoided in hyperbilirubinemic neonates (displaces bilirubin from albumin) and must not be given with IV calcium-containing solutions in newborns (fatal precipitates) |
| Acyclovir | Nephrotoxicity (ensure hydration), neutropenia; monitor creatinine and CBC |
Listed in priority order.
- Airway, breathing, circulation — monitor respirations, apnea, SpO₂, heart rate, capillary refill, blood pressure; report hypotension or poor perfusion immediately and prepare fluid bolus and support
- Treat hypoglycemia promptly — feed, give dextrose gel, or start IV dextrose per protocol; recheck glucose within the ordered interval (often 30–60 minutes); a symptomatic infant needs IV glucose
- Cultures before antibiotics, then antibiotics without delay; give on time, verify weight-based doses, monitor levels
- Thermoregulation — neutral thermal environment; skin-to-skin; cold stress worsens both hypoglycemia and sepsis
- Infection prevention — hand hygiene before and after every contact, central-line insertion and maintenance bundles, limit visitors with respiratory or GI illness, clean equipment
- Nutrition — early and frequent breastfeeding; strict intake and output; daily weight
- Neurologic observation — seizures, tone, level of alertness
- Family support — explain tests and reasons for monitoring; support breastfeeding and milk expression
- Feed early and often: at least 8–12 times in 24 hours; do not skip night feeds
- Keep the baby warm with skin-to-skin contact and appropriate clothing
- Hand hygiene for everyone who touches the baby; keep sick visitors away; keep the umbilical cord clean and dry
- Seek care immediately for a temperature of 38.0 °C (100.4 °F) or higher or below 36.5 °C (97.7 °F), poor feeding or refusing feeds, unusual sleepiness or floppiness, fast or difficult breathing or grunting, color change, fewer wet diapers, vomiting, or a bulging soft spot. A young infant with fever needs urgent evaluation — do not give fever medicine to mask it first
- Mothers with diabetes: good glucose control during pregnancy lowers the baby's risk
- Pregnant clients: GBS screening late in pregnancy and intrapartum antibiotics when indicated protect the newborn
| Complication | What to watch for |
|---|
| Hypoglycemic brain injury | Seizures, persistent lethargy, later developmental delay and visual problems |
| Septic shock | Tachycardia, prolonged capillary refill, mottling, hypotension, oliguria, metabolic acidosis |
| Meningitis | Bulging fontanel, seizures, high-pitched cry, irritability |
| DIC | Petechiae, bleeding from puncture sites, thrombocytopenia |
| Persistent hypoglycemia | Low glucose beyond 48 hours or high glucose requirements — suspect hyperinsulinism |
- At-risk for hypoglycemia: IDM, LGA, SGA, late preterm, cold stress, sepsis
- IDM/LGA → hyperinsulinism; SGA/preterm → low glycogen stores
- Hypoglycemia is often asymptomatic; signs are jitteriness, poor feeding, lethargy, hypotonia, apnea, seizures
- AAP 2011: below 25 mg/dL (1.4 mmol/L) at 0–4 hours and below 35 mg/dL (1.9 mmol/L) at 4–24 hours → feed and recheck; target 45 mg/dL (2.5 mmol/L) before feeds
- Symptomatic and below 40 mg/dL (2.2 mmol/L) → IV glucose: D10W 2 mL/kg slowly, then infusion
- Dextrose gel 40%, 0.5 mL/kg buccal, then feed
- Sepsis signs are subtle: temperature instability and poor feeding
- Blood culture before antibiotics, but never delay antibiotics
- EOS = GBS and E. coli; empiric ampicillin + gentamicin
- Gentamicin → ototoxic, nephrotoxic — monitor levels
- Hand hygiene is the most effective prevention of late-onset sepsis
Country Notes
United States
- Universal antenatal GBS screening at 36 0/7–37 6/7 weeks with intrapartum antibiotic prophylaxis (penicillin preferred) when colonized; prophylaxis given 4 hours or more before birth is considered adequate.
- Glucose is reported in mg/dL.
Philippines
- Glucose is often reported in mmol/L; convert using mg/dL ÷ 18.
- The DOH Essential Intrapartum and Newborn Care protocol promotes early skin-to-skin contact, early exclusive breastfeeding, and dry cord care (nothing applied to the cord), which reduce hypothermia, hypoglycemia, and infection.