Sex-specific effects of neonatal oral sucrose treatment on growth and liver choline and glucocorticoid metabolism in adulthood

Neonatal Sucrose and Internalizing Behaviors at 18 Months in Children Born Very Preterm

Importance

In the neonatal intensive care unit (NICU), neonates born very preterm (<33 weeks' gestation) are exposed to great numbers of painful procedures, which is associated with more internalizing (anxiety and depressive) behaviors later in childhood. Oral sucrose is commonly used in NICUs to treat acute procedural pain and is effective in reducing behavioral responses, but the long-term associations between oral sucrose and child behaviors have not yet been examined.

Objective

To examine associations between cumulative neonatal pain and sucrose exposure in early life (prior to approximately 32 weeks postmenstrual age), in relation to child behaviors (internalizing and externalizing) at 18 months corrected age (CA) in children born very preterm and to examine whether the associations are sex specific.

Design, Setting, and Participants

In a prospective, longitudinal cohort study, children born very preterm (24-32 weeks' gestational age [GA]) were recruited from 2015 to 2019 from 3 tertiary NICUs in Canada and attended a follow-up visit at 18 months CA. Data analysis was performed from February to May 2024.

Exposures

The clinical protocol to treat acute procedural pain at site 1 was facilitated tucking with nonnutritive sucking; sites 2 and 3 used 24% sucrose with nonnutritive sucking. Prospective clinical record review was conducted (eg, number of painful procedures, cumulative sucrose dose, analgesia, sedation, days receiving mechanical ventilation, and surgical procedures).

Main Outcomes and Measures

Parents reported on their child's behavior on the Child Behavior Checklist (CBCL; 1.5 to 5 years) yielding internalizing and externalizing scores.

Results

In total, 192 children (110 male [57%]) were included in the current study. After applying propensity score weights to adjust for clinical factors across sucrose and nonsucrose sites and accounting for neonatal pain, cumulative sucrose (milliliters) in early life was not associated with internalizing scores (B = 0.62; 95% CI, -0.46 to 1.99). However, greater neonatal pain exposure was significantly associated with higher 18-month CBCL internalizing scores (B = 0.01; 95% CI, 0.0003 to 0.0135; R2 = 1.8%). There were no associations with externalizing scores, and associations were not moderated by child sex.

Conclusions and Relevance

In this cohort study of children born very preterm across 3 tertiary NICUs in Canada, cumulative sucrose exposure in early life demonstrated no association with child behavior and did not ameliorate the association between greater neonatal pain and internalizing behaviors. Further research is needed to identify pain management strategies that can effectively mitigate or protect against adverse behavioral outcomes in children born very preterm.

A longitudinal observational study on the epidemiology of painful procedures and sucrose administration in hospitalized preterm neonates

Although sucrose is widely administered to hospitalized infants for single painful procedures, total sucrose volume during the entire neonatal intensive care unit (NICU) stay and associated adverse events are unknown. In a longitudinal observation study, we aimed to quantify and contextualize sucrose administration during the NICU stay. Specifically, we investigated the frequency, nature, and severity of painful procedures; proportion of procedures where neonates received sucrose; total volume of sucrose administered for painful procedures; and incidence and type of adverse events. Neonates <32 weeks gestational age at birth and <10 days of life were recruited from four Canadian tertiary NICUs. Daily chart reviews of documented painful procedures, sucrose administration, and any associated adverse events were undertaken. One hundred sixty-eight neonates underwent a total of 9093 skin-breaking procedures (mean 54.1 [±65.2] procedures/neonate or 1.1 [±0.9] procedures/day/neonate) during an average NICU stay of 45.9 (±31.4) days. Pain severity was recorded for 5399/9093 (59.4%) of the painful procedures; the majority (5051 [93.5%]) were heel lances of moderate pain intensity. Sucrose was administered for 7839/9093 (86.2%) of painful procedures. The total average sucrose volume was 5.5 (±5.4) mL/neonate or 0.11 (±0.08) mL/neonate/day. Infants experienced an average of 7.9 (±12.7) minor adverse events associated with pain and/or sucrose administration that resolved without intervention. The total number of painful procedures, sucrose volume, and incidence of adverse events throughout the NICU stay were described addressing an important knowledge gap in neonatal pain. These data provide a baseline for examining the association between total sucrose volume during NICU stay and research on longer-term behavioral and neurodevelopmental outcomes.

Long-term effects of neonatal pain and sucrose treatment

Purpose

In neonatal intensive care units, applying sucrose solution for analgesia is now a routine treatment for mild procedural pain. Studies of animal and human infants provide clear evidence of benefits in the short term, but few studies have investigated the long term benefits. Thus, we determined whether sucrose could ameliorate painful stimulation during infancy in Sprague-Dawley rats and also explored the long-term effects of repeated sucrose administration during infancy. Female and male rats were included to investigate sex-related differences.

Methods

Rat pups were stimulated either with painful or tactile stimuli for the first 14 days of their lives. Pups were pretreated either with sucrose or not treated before stimulation. Behavioral tests were conducted during adolescence and adulthood. Hotplate, rotarod, open field, elevated plus maze, and radial arm water maze tests were employed to assess the behavioral consequences of early life manipulations and treatments.

Results

Painful stimulation during infancy increased the sensitivity to pain later in life, and sucrose did not remedy this effect. Motility, coordination, anxiety, and cognition tests in adulthood obtained mixed results. Pain during infancy appeared to increase anxiety during adulthood. Learning and memory in adulthood were affected by pain during infancy, and sucrose had a negative effect even in the absence of pain. No sex-related differences were observed in any of the behavioral tests by employing this model of neonatal pain.

Conclusion

Painful stimulation during infancy resulted in deficiencies in some behavioral tests later in life. Sucrose pretreatment did not mitigate these shortcomings and it actually resulted in negative outcomes.