The Relationship Between Newborn Hypoglycemia Screening and Exclusive Breastfeeding at Hospital Discharge
by Anne Eglash MD, IBCLC, FABM
Does newborn hypoglycemia screening increase the likelihood of supplementation?
The American Academy of Pediatrics, the Academy of Breastfeeding Medicine, the Canadian Paediatric Society and other major health organizations recommend newborn hypoglycemia screening based on risk factors, the most common being birth parent with diabetes, preterm birth, and small or large for gestational age (SGA, LGA). Studies on the neurocognitive outcomes among newborns exposed to transient (not severe or prolonged) hypoglycemia are mixed, with a most recent large study showing no negative neurocognitive outcomes at later ages.
According to the authors of this week’s study, there are downsides to newborn hypoglycemia screening including a delay in breastfeeding while waiting for test results, infant pain, and parental anxiety about feeding inadequacy. Although it has been assumed that newborn hypoglycemia screening has a negative impact on exclusive breastfeeding rates, the evidence has not been strong, so the authors of this study sought to compare exclusive breastfeeding rates at 24 hours in unscreened newborns with those of euglycemic newborns screened for hypoglycemia.
This is a retrospective cohort study of 10,965 healthy newborns between Feb 2018 and June 2018 at Hospital Montfort in Ottawa. The hospital performed routine hypoglycemia screening among infants of diabetic birthing parents, LGA, SGA, and infants with clinical signs such as jitteriness. ‘Inadequate breastfeeding’ was also considered a risk factor for hypoglycemia. The study compared exclusive breastfeeding rates at 24 hours among newborns who underwent hypoglycemia screening vs those who didn’t, and excluded all newborns who were diagnosed with hypoglycemia and treated.
The researchers found, as expected, that the newborns who underwent hypoglycemia screening were more likely to have a birthing parent with diabetes, to be premature, LGA or SGA, as compared to those who did not undergo screening.
Despite having normal blood sugars, 28.6% of screened newborns were exclusively breastfeeding at 24 hours as compared to 42.8% of unscreened newborns.
What else? See the question!
- The most common reason for a full 24 hours of hypoglycemia screening was LGA status.
- The newborns who underwent a full 24 hours of hypoglycemia screening had lower exclusive breastfeeding rates than newborns who underwent 12 hours of hypoglycemia screening.
- The decreased exclusive breastfeeding rate among screened newborns was similar regardless of the reason for screening.
See the Answer
There has been limited investigation of the unintended effects of routine screening for asymptomatic hypoglycemia in at-risk newborns. This study aimed to explore whether rates of exclusive breastfeeding were lower in screened babies than in unscreened babies.
This retrospective cohort study conducted in Ottawa, Canada, used data from Hôpital Montfort’s electronic health information system. Healthy singleton newborns discharged between Feb. 1, 2014, and June 30, 2018, were included. We excluded babies and mothers with conditions expected to interfere with breastfeeding (e.g., twins). We investigated the association between postnatal screening for hypoglycemia and initial exclusive breastfeeding (in the first 24 hours of life).
We included 10 965 newborns; of these, 1952 (17.8%) were fully screened for hypoglycemia. Of screened newborns, 30.6% exclusively breastfed and 64.6% took both formula and breastmilk in the first 24 hours of life. Of unscreened newborns, 45.4% exclusively breastfed and 49.8% received both formula and breastmilk. The adjusted odds ratio for exclusive breastfeeding in the first 24 hours of life among newborns screened for hypoglycemia was 0.57 (95% confidence interval 0.51–0.64).
The association of routine newborn hypoglycemia screening with a lower initial rate of exclusive breastfeeding suggests a potential effect of screening on early breastfeeding success. Confirmation of these findings might warrant a re-evaluation of the net benefit of asymptomatic postnatal hypoglycemia screening for different newborn populations at risk of hypoglycemia.
This is a well-designed study that excluded newborns who were diagnosed with and treated for hypoglycemia, using the Canadian Paediatric Society Guidelines. More research is needed on the negative consequences of newborn hypoglycemia screening, given evidence that it increases the risk of mixed feeding in the first 24 hours. The dose response relationship between more screening (24 hours vs 12 hours) and less exclusive breastfeeding supports the theory that screening interrupts breastfeeding. The question is why. It is possible that families of high-risk infants were advised to supplement with formula to prevent hypoglycemia, especially if they were told that it would decrease the number of heel sticks.
There is no evidence regarding the ideal interval or duration of hypoglycemia screening. Given that longer duration of screening (24 vs 12 hours) increases the risk of mixed feeding, guidelines should consider decreasing the interval and duration of screening, particularly for at-risk infants who are nursing fine and who appear clinically well.