2.5 Hypoglycaemia

Key Points - Case Study B
Joanne asks you what she can do before the baby is born to help her successfully breastfeed.
The Ten Steps to Successful Breastfeeding, designed by the
WHO and
UNICEF summarise the maternity practices needed to support and encourage breastfeeding.
- Topic 2.1: Preparation Before Birth
- Inform all pregnant women about the benefits and management of breastfeeding
Joanne's baby Rosie is born by spontaneous vaginal delivery at 37 weeks following a 15-hour labour. She had been given pethidine (meperidine) and an epidural for pain relief during labour. Are there any features of her birthing experience that may affect breastfeeding?
- Topic 2.2: Birthing Factors that Affect Breastfeeding
- Labour analgesia and near-term birth
- Topic 2.3: Management After Birth
- Place Rosie in skin-to-skin contact; Encourage breastfeeding on demand; Practice rooming-in, allow Joanne and Rosie to remain together 24 hours a day; Give Rosie no food or drink other than breastmilk, unless medically indicated; Give Rosie no artificial teats or dummies; Show Joanne how to breastfeed and how to maintain lactation even if she should be separated from Rosie.
Rosie is now 24 hours old. Although she seems interested in the breast, she is not attaching well and tends to slip off the breast easily. What is the most appropriate management to suggest at this time?
- Topic 2.4: Poor Attachment
- Investigate whether there an underlying reason; Maximize breastfeeding opportunities; Protect the milk supply; Feed the baby; Nipple shields may be useful.
Because Rosie has not been feeding well, the hospital staff are concerned that she may develop hypoglycaemia. Is hypoglycaemia likely to occur in a healthy term breastfed neonate?
- Topic 2.5: Hypoglycaemia
- Healthy full-term infants do not develop symptomatic hypoglycaemia simply as a result of underfeeding.
Because Rosie has not been feeding well, the hospital staff are concerned that she may develop hypoglycaemia. Is hypoglycaemia likely to occur in a healthy term breastfed neonate?
Healthy full-term infants do not develop symptomatic hypoglycaemia simply as a result of underfeeding.1
Healthy full term neonates are able to adapt from an intrauterine environment where their energy needs are supplied, to an extrauterine environment where they regulate their own glucose levels within a short period of time. Blood glucose levels fall within the first hour and begin to rise soon after, becoming stable 2-3 hours after birth whether the infant has been fed or not. Assuming normal glycogen and adipose stores, infants produce energy by gluconeogenesis, glycogenolysis and ketogenesis.
Skin-to-skin contact and early and frequent breastfeeding helps protect infants at risk from hypoglycaemia. Feeding breastmilk not only provides an exogenous source of energy, but also enhances gluconeogenesis and the production of ketone bodies that can be used by the brain to protect neurological function. However, variables such as gestational age, age since birth, and other energy needs affect the infant's ability to provide sufficient energy to maintain normal function.2
Which infants are at risk and should be monitored?
- There is no evidence that routinely measuring blood glucose in a healthy, full-term infant is helpful, and it may be potentially harmful for establishing breastfeeding.
- Any infant who becomes symptomatic should be tested and treated according to the result.
- Infants at risk for hypoglycaemia such as those who:
- are premature or small for gestational age;
- have suspected inborn errors of metabolism or endocrine disorders, infections, hypothermia or respiratory distress; or
- suffered perinatal stress (including hypoxia or low APGAR score)
- Infants of mothers who have diabetes or other conditions with hyperinsulinemia are at greater risk of hypoglycemia and should have their blood glucose checked within 30-60 minutes of birth.1,2
- While bedside blood glucose monitors are useful screening tools, plasma glucose levels should be confirmed by the laboratory. Plasma glucose levels are 15% higher than whole blood levels.
- Monitoring before a feed should continue until the levels are normal and stable.
Definition of hypoglycemia
Hypoglycaemia is hard to define in the neonate because of the lack of a significant correlation between blood (or plasma) glucose levels, symptoms of hypoglycaemia, and long term neurological sequelae. Some neonates are asymptomatic but have extremely low plasma glucose levels while symptoms of hypoglycaemia such as irritability, tremor, lethargy, hypotonia, high pitched cry, cyanosis, hypothermia, seizures, vasomotor instability, apnoea, poor or inadequate sucking 3 4 are often non-specific and may be the result of other pathological conditions.
Therefore there is no standard definition of hypoglycaemia that can be applied universally to neonates 4 with therapeutic operational thresholds being more suitable indicators for intervention.
Operational thresholds for plasma glucose levels
-
Asymptomatic infants at risk for hypoglycemia >2hours old - <2.0 mmol/L (36ml/dL)
- Breastfed infants may have a slightly lower threshold.
- In the first two hours after birth, levels may be as low as 1.6 mmol/L (28mg/dL)
-
Symptomatic infants at any age - <2.5 mmol/L (45 mg/dL)
- The therapeutic target is to maintain plasma glucose levels above 2.5 mmol/L (45mg/dL) 1 3
Treatment
Asymptomatic infants with plasma glucose > 1.4mmol/L
- Continue breastfeeding every 1-2 hours or feed 3-5 ml/Kg of expressed breast milk or substitute nutrition (not glucose water).
- Monitor plasma levels prior to each feed until levels are stable and above the treatment threshold.
- If plasma glucose levels remain low, the infant is not able to suck or tolerate oral feeds commence IV glucose therapy
Symptomatic infants or infants with plasma glucose < 1.1 - 1.4mmol/L
- Initiate IV glucose therapy - do not rely on nasogastric or oral feeding.
- Adjust rate of glucose infusion so that plasma glucose levels in symptomatic infants are be maintained >2.5mmol/L.
- Once the infant is stable encourage frequent breastfeeding.
- Monitor plasma levels prior to each feed until levels are stable and above the treatment threshold.
Notes
- # Wight NE et al. (2006) ABM Clinical protocol #1 Guidelines for glucose monitoring and treatment of hypoglycemia in breastfed neonates
- # Fernandez BAI et al. (2011) Neonatal hypoglycemia - current concepts. IN: Rigobelo EC (ed) Hypoglycemia - Causes and occurences.
- # Wight NE (2006) Hypoglycemia in breastfed neonates
- # Eidelman AI (2001) Hypoglycemia and the breastfed neonate