Hypoglycemia and the Breastfed Newborn

Hypoglycemia and the Breastfed Newborn

Hypoglycemia is the technical term for low blood sugar (low concentrations of glucose, the sugar found in blood). When the body's rate of use of glucose is greater than the rate of glucose production, the plasma glucose concentration falls. If it falls too far too fast in the newborn period, hypoglycemia results.

Hypoglycemia is not a common condition in newborn babies and breastfeeding early and often will almost always prevent it. Further, the baby who is not showing any symptoms of hypoglycemia does not need glucose supplements. They should not be given routinely.

Symptomatic hypoglycemia in newborns is largely due to delayed or inadequate feeding and is more likely to occur when mother and baby are separated after birth. Some newborns are given sugar water on the erroneous assumption that this will prevent hypoglycemia. Instead, giving glucose water causes a sudden rise in the blood glucose levels, which in turn stimulates the secretion of insulin by the pancreas. The high level of insulin results in an equally sudden drop in glucose levels. It is interesting to note that the treatment for hypoglycemia in adults is small, frequent, high-protein meals. That is exactly what the baby gets when he is allowed to breastfeed on demand from birth.

Immediate and frequent feedings of colostrum, preferably ten to twelve feedings per day in the first few days, stabilize blood glucose levels. Undiluted human milk is the best food, particularly for preterm infants.

Infants at risk for hypoglycemia include those who are small- or large-for-gestational age, preterm, have some type of neonatal infection, are oxygen deprived, chilled, show meconium staining, have a central nervous system abnormality, congenital glucose metabolic problems, or other perinatal stress. If left untreated, symptomatic hypoglycemia does need to be taken seriously.

Researchers and physicians have differing opinions as to what blood glucose levels constitute hypoglycemia. The most current research-based definition of hypoglycemia in any newborn in the United States is a serum/plasma blood glucose concentration lower than 40 mg/dl (whole blood glucose level lower than 35 mg/dl). The limit is allowed to go lower by some physicians in the absence of symptoms -- whole blood concentrations of 30 mg/dl for full-term infants, and 20 mg/dl for premature or small-for-gestational age babies. In one study, asymptomatic (except for jitteriness) newborns with blood glucose levels below 20 mg/dl were given human milk alone. These children were neurologically tested a number of years later and found to have no problems.

Pregnant women who have healthy diets and avoid smoking lower the risk of newborn hypoglycemia by having healthier babies. However, there are some maternal risk factors which may increase the chances of newborn hypoglycemia such as diabetes (including gestational), toxemia, drug ingestion, pregnancy-induced hypertension, a difficult labor, or glucose solutions given intravenously during labor (IV).

Glucose IVs should be avoided during labor unless absolutely necessary. If the mother receives a glucose IV during labor and delivery, the baby's glucose level also rises. This steady source of glucose is abruptly cut off at birth and the infant becomes fully dependent upon his own resources unless he is given glucose from other sources, for example, by being put immediately to the breast.

A difficult labor can stress a newborn, depleting his glucose stores. Laboring women should be encouraged to walk, eat, change positions, and avoid epidural anesthesia to help labor progress. Lying on one's back during labor can also increase the risk for hypoglycemia by stressing the fetus.

Mothers with insulin-dependent diabetes mellitus or gestational diabetes need to be aware that their infants may be at higher risk for hypoglycemia. If the mother had uncontrolled diabetes during her pregnancy, her baby is more likely to be premature and experience respiratory distress syndrome or physiologic jaundice. The baby may be cared for in a neonatal intensive care unit or may not nurse well. Early and frequent colostrum feedings will help stabilize the baby's blood glucose level. If the diabetic mother maintains a normal glucose level throughout pregnancy, labor, and birth, her baby is not likely to have serious problems.

In some hospital settings, newborns are at risk for developing hypoglycemia even after an uneventful labor and delivery. Babies who are not fed soon after birth, are left uncovered in a nursery warmer, or are left in a nursery to cry, are under stress. As a result they use up their stores of glucose and are at risk for developing hypoglycemia. It is important to put the baby to the breast immediately after birth, make sure the baby is kept warm and dry (preferably in the mother's arms), and not allow long separations when the baby may be left to cry.

If a healthy, full-term baby is sleepy and not nursing well in the early days, the mother may wish to express her milk and supplement breastfeeding with this milk, giving it to him by methods other than artificial nipples. Rooming-in with the baby or being at home will give her frequent opportunities to offer the breast. Nighttime feedings are important to help establish a milk supply.

If the baby is at risk for hypoglycemia, the new mother may want to try waking the baby frequently during the day. It's important that the baby breastfeed efficiently and often in the early days. Avoiding pacifiers will help prevent nipple confusion and aid in getting breastfeeding off to a good start.

The best way to stabilize blood sugar and prevent hypoglycemia in all infants is prompt and frequent feedings of colostrum and human milk.


Crase, B.L. Hypoglycemia and the breastfed newborn. BREASTFEEDING ABSTRACTS 1995; 15(2):11.

Gentz, J. et al. On the diagnosis of symptomatic neonatal hypoglycemia. Acta Paediatr Scand 1969; 58:449-59.

Mohrbacher, N. and J. Stock. THE BREASTFEEDING ANSWER BOOK. Schaumburg, Illinois. La Leche League International, 1997.

Pagliara, A.S. et al. Pediatrics. Seventeenth Edition. Norwalk, Connecticut: Appleton-Century-Crofts, 1982. "Hypoglycemia," pp. 283-88.

Sexson, W.R. Incidence of neonatal hypoglycemia: a matter of definition. J Pediatr 1984; 105(1):149-50.

Smallpiece, V. et al. Immediate feeding of premature infants with undiluted breastmilk. Lancet 1964; 2:1349-52.

La Leche League International, Inc.


By Edie Orr and Betty Crase

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