Your newborn and low blood sugar levels

Posted on Jun 14th, 2019

Hypoglycaemia in a newborn can be tricky to navigate. Sr Burgie Ireland unpacks what you need to know.

Your newborn and low blood sugar levels

Immediately after birth, your baby must breathe on his own and be kept warm to stay alive. To do this, he needs energy, which comes from sugar. The best source of sugar for your baby is colostrum, or your first milk. Your breasts are prepped for this task during pregnancy, and during the first few days after birth a newborn needs to drink colostrum every two to three hours. Think of it as condensed milk − thick and yellowish, rich and very sweet.

There is a risk of low blood sugar levels (hypoglycaemia) in the first 12 hours after birth in full-term babies, and in the first 36 hours for small or preterm babies.

Low blood sugar levels in the first few hours after birth (called “transient hypoglycaemia”) is normal, according to the American Academy of Paediatrics Guidelines for Neonatal Hypoglycaemia. The purpose of lower blood sugar levels is to make sure the baby feeds often and doesn’t sleep for too long between feeds. Remember, a newborn’s stomach can only hold, at most, 20ml (or four teaspoons) of milk at a time, and frequent feeding stimulates the pituitary gland in the mother’s brain to produce essential breastfeeding hormones known as oxytocin and prolactin.

ALSO SEE: How to prepare for breastfeeding

Acclaimed neonatologist and neuroscientist Dr Nils Bergman, reminds us that babies are born prewired to be fed about every hour, and babies’ sleep cycles are approximately one hour long. This means when your baby uses up her sugar reserves, colostrum helps to restore those levels. When sugar stores are not replenished, babies can become hypoglycaemic with some of the complications.

There is some controversy among healthcare professionals as to what a newborn’s blood sugar levels should be. For adults, a normal blood sugar level varies between 3 and 5.8 mmol/L. When babies are just an hour or
two old, normal levels are just under 2 mmol/L. However, this should rise to between 2.5 and 2.8 mmol/L within the next two to three days once a feeding pattern (whether breast or bottle) has been established.

When things go wrong

Low blood sugar levels should start improving within the first 24 hours. When these levels stay persistently low, or deteriorate, interventions like glucose feeds, a drip or admission to the neonatal intensive care unit (NICU), may be necessary. Tests will be done to find the cause of low levels.

Gauteng-based dietician and lactation consultant Lizelle Payne cautions that low blood sugar levels can be exacerbated by pregnancy- and birth-related complications like small-for-date babies (also large-for-date babies when the mom is diabetic), a discordant (or smaller) twin, prematurity, infections, babies with respiratory distress, medications (these include narcotics and epidurals during labour), C-sections and delayed feeding.

Symptoms of hypoglycaemia

You know how you feel when you haven’t eaten for a while or when you’re craving chocolate – hot and cold, grumpy and irritable? Your baby feels the same way and tells you this through her body language. These signals include a high-pitched anxious cry and jittering with an exaggerated moro (startle) reflex. Your baby will also be lethargic and it may be difficult to feed her if she is too weak to latch and suck. Her breathing may also be faster than usual.

ALSO SEE: 8 newborn reflexes and why your little one has them

What to do

If your baby shows signs of hypoglycaemia or is sleepy and reluctant to feed, blood sugar levels can be checked with a heel-prick test. “This test is quick, easy and convenient,” says Lizelle, “but can be unreliable. Lab tests may take longer and are more expensive, but they’re accurate. They can be the difference between implementing necessary or unnecessary interventions or simply persevering with skin-to-skin kangaroo care and breastfeeding.”

Providing there are no complications, breastfeeding at least every two hours, including during the night, is best. Lizelle emphasises the importance of skin-to-skin contact and breastfeeding within the first hour after birth whenever possible – even if you have had a C-section. “If your baby is in NICU, you should be encouraged to express her milk as soon as possible to establish a milk supply.”

ALSO SEE: 8 breastfeeding tips and tricks for new moms

When babies are reluctant to suck, expressed breast milk can be given using a teaspoon, syringe or medicinal feeding cup.

When it was found that low blood sugar levels in the newborn can affect their brain’s metabolic functioning, many healthcare professionals began insisting on regular heel-prick blood tests and even formula feeding in the first few days after birth while waiting for the mother’s milk to come in. However, this may have been because, in the past, mom and baby were routinely separated and feeds were restricted to a four-hourly schedule. With mom and baby rooming in, this doesn’t happen anymore and has helped to reduce the incidence of hypoglycaemia.

Most babies make a quick and easy transition from life in the womb to cuddling in their mom’s arms. If you’re worried, trust your instincts, speak to your healthcare provider and contact a lactation consultant.