A common worry for many families is that their baby might suffer from low blood sugar (hypoglycemia) during the first few weeks after birth. Is this something to be concerned about? Are there babies who are more at risk? And how can we avoid this situation? Here, we try to clarify this issue and answer some basic questions.

What is neonatal hypoglycemia?

Glucose (sugar) is used to produce energy and is needed to carry out all the processes that occur in our body.

Hypoglycemia, low blood sugar levels, occurs when a baby’s body consumes more glucose than it produces, causing a drop in the concentration of glucose in the baby’s blood.

Do babies not have enough glucose at birth?

During the third trimester of pregnancy, babies receive glucose through the umbilical cord. Babies accumulate it in their liver in the form of glycogen and thus will have it available at birth and will be able to cope with the necessary quick cardiovascular, respiratory, and metabolic adaptation. When a baby is born, glucose levels reflect those of the mother. Then, during the next two hours, blood glucose values typically decrease.

A healthy full-term newborn has reserves to meet these needs, but the changes must be gradual, and extra “support” measures – which we will discuss later – must be received to avoid rapid changes, which are not tolerated well. Glycogen breakdown is not immediate, so there is a time delay, as we have mentioned, with lower glucose values in the first hours after birth.

What are these extra “support” measures?

Babies require very little to make their arrival into the world simpler and more pleasant. Just the warmth of their mother’s body and their mother’s milk help avoid the adjustment being too abrupt.

Healthy, full-term babies don’t regulate their body temperature well and have difficulties maintaining body heat, no matter how warmly wrapped they are. The best way to keep their temperature stable is to be dry and in real skin-to-skin contact with their mother, and if both are wearing clothes, it doesn’t work.

In addition, babies who are separated from their mothers cry to be reunited with them, which causes extra energy expenditure that can be avoided very easily.

Another clear additional “support” is breastfeeding. A first breastfeeding of colostrum within half an hour after birth and short, very frequent feeds during the first hours of life are recommended.

But aren’t some babies more at risk for low blood sugar?

Yes, there is a greater chance of a sudden drop in blood sugar in some cases. This may be due to causes related to the baby, the mother, or the type of birth. Here is a list of the leading causes:

• Babies weighing more than 4 kilos or less than 2.5 kilos
• Premature babies
• The smaller baby, in the case of twins
• Infection
• Metabolic diseases
• Stress during labor or asphyxia
• Getting cold
• Poorly controlled maternal diabetes
• High blood pressure
• When the mother smokes
• Very long labor, and the mother is not allowed to eat or drink
• Mother/baby separation

In these cases, babies are usually checked routinely. However, some authors point out that in the case of babies weighing more than 4 kilos, it would not be necessary. Just like babies with a standard weight, it would be enough to keep the baby in skin-to-skin contact with the mother since these babies have a bigger accumulation of body fat that can be transformed into ketone bodies that provide the energy that the baby’s body needs.

What are the values for which a baby is considered to be hypoglycemic?

This is a very controversial subject on which much extremely conflicting information can be found. There is no international consensus on defining a value for neonatal hypoglycemia. In addition, it should be remembered that blood sugar levels are different according to the baby’s age: a baby three hours old is not the same as a just-born baby, so values should be in accordance with age.

What symptoms does a baby have in case of hypoglycemia?

Infants suffering from hypoglycemia may have no symptoms at all, and when they do appear, they are very different:

• Blue or very pale skin color
• Breathing problems, rapid breathing, or growling
• Irritability or sleepiness
• Lack of muscle tone
• Poor milk intake or vomiting
• Low body temperature
• Sweating, shivering, shaking or convulsions

What happens if a baby suffers from hypoglycemia?

Depending on the age and the blood sugar values, a neonatologist will decide what should be done. The ABM protocol sets out the following guidelines:

Babies with no clinical signs:

1. Continue breastfeeding (approximately every 1-2 hours) or expressed colostrum: 1-5 ml/kg or artificial milk.
2. Check blood glucose levels before and after feeding.
3. If the glucose levels remain low despite feeding, initiate intravenous glucose therapy.
4. Breastfeeding can continue during intravenous glucose

It is not advisable to administer glucose solutions to the baby, as the rebound effect they produce may worsen the condition.

Can babies over one month old suffer from hypoglycemia if they do not breastfeed for many hours?

Another common worry of mothers is that their baby, after the first weeks, may suffer from low blood sugar if they do not breastfeed regularly.

Healthy babies who have recovered their birth weight optimally (between the tenth and fifteenth day of life) and who breastfeed on demand – between 8 and 12 feeds in 24 hours – are not at risk of low blood sugar.