High-Dose Docosahexaenoic Acid in Newborns Born at Less Than 29 Weeks' Gestation and Behavior at Age 5 Years: Follow-Up of a Randomized Clinical Trial

Importance

Children born at less than 29 weeks' gestation are at risk of behavioral difficulties. This may be due in part to the lack of transplacental supply of docosahexaenoic acid (DHA), a key fatty acid with structural and functional roles in the brain.

Objective

To determine whether meeting the neonatal DHA requirement through supplementation is associated with improved behavioral functioning of children born at less than 29 weeks' gestation.

Design, Setting and Participants

This was a follow-up of children from 10 Australian participating centers in a multi-center, blinded, parallel group randomized clinical trial of infants born at less than 29 weeks' gestation conducted from June 2012 and September 2015, excluding those with additional fatty acid supplementation or major congenital or chromosomal abnormalities. Follow-up took place from August 2018 to May 2021. Parents of surviving children who had not withdrawn from the original trial were invited to complete questionnaires when the child turned 5 years' corrected age.

Interventions

Infants were randomized to receive daily enteral emulsions providing 60 mg/kg/d of DHA or a soy-oil emulsion (with no DHA) from within the first 3 days of enteral feeding until 36 weeks' postmenstrual age or discharge home, whichever occurred first.

Main Outcomes and Measures

The primary outcome of this follow-up was parent-rated behavior and emotional functioning as indicated by the Total Difficulties score of the Strengths and Difficulties Questionnaire. Parents also completed questionnaires about their child's behavioral manifestations of executive functioning, as well as a range of health outcomes to assess potential longer-term side effects of DHA intervention.

Results

Primary outcome data were available for 731 children (76% of 958 surviving eligible children; 361 in the intervention group and 370 in the control group). Of these 731, 452 (47%) were female, and the mean (SD) corrected age at follow-up was 5.4 (0.5) years. Following imputation for missing data, the mean Total Difficulties score was the same in both groups (intervention group, n = 465; mean [SD], 11.8 [6.3]; control group, n = 493; mean [SD], 11.8 [6.0]; mean difference adjusted for sex, gestational age stratum, and hospital, 0.01; 95% CI, -0.87 to 0.89; P = .98). There was no evidence for differences between the groups in any secondary outcomes of behavior, executive functioning, or health.

Conclusions and Relevance

In this follow-up of a randomized clinical trial, enteral DHA supplementation at the equivalent of the estimated in utero dose for infants born at less than 29 weeks' gestation did not improve behavioral functioning at age 5 years. There were no indications of adverse effects with DHA supplementation.

Trial Registration

Australian New Zealand Clinical Trial Registry: ACTRN12612000503820.

Subgroup analyses of a randomized trial of DHA supplementation for infants born preterm with assessments of cognitive development up to 7-years of age: What happens in infants born <29 weeks' gestation?

A recent trial showed that high-dose docosahexaenoic acid (high-DHA) supplementation of infants born <29 weeks' gestation improves intelligence quotient (IQ) at five years' corrected age. However, this finding has not been detected by other trials of DHA, which either did not measure IQ or included more mature infants. We analyzed the subgroup of 204 infants born <29 weeks' from our earlier randomized trial of high-DHA (∼1 % total fatty acids) or standard-DHA (∼ 0.3 % total fatty acids). Participants were assessed for cognition at 18 months, and IQ and behavior at seven years' corrected age. No group differences were detected for mean cognitive, IQ or behavior scores. At 18 months, 18.8 % of children in the high-DHA group had a cognitive score <85, compared with 31.1 % of children in the standard-DHA group, but at seven years there was no difference. Although an underpowered post-hoc subgroup analysis, this study provides limited support to recommendations that infants born <29 weeks' gestation require supplemental DHA.

Mediation Analysis to Untangle Opposing Associations of High-Dose Docosahexaenoic Acid With IQ and Bronchopulmonary Dysplasia in Children Born Preterm

Importance

High-dose omega-3 docosahexaenoic acid (DHA) supplementation of children born at less than 29 weeks' gestation has been shown to improve IQ despite increasing the risk of bronchopulmonary dysplasia (BPD). Given that BPD is associated with poorer cognitive outcomes, it is unclear whether the increased risk of BPD with DHA supplementation is associated with decreased benefit to IQ.

Objective

To investigate whether the increased risk of BPD with DHA supplementation was associated with diminished IQ benefit.

Design, Setting, and Participants

This cohort study used data collected from a multicenter, blinded, randomized controlled trial of DHA supplementation in children born at less than 29 weeks' gestation. Participants were recruited from 2012 to 2015 and followed up until 5 years' corrected age. Data were analyzed from November 2022 to February 2023.

Interventions

Enteral DHA emulsion (60 mg/kg/d, to match the estimated in-utero requirement) or a control emulsion from the first 3 days of enteral feeds until 36 weeks' postmenstrual age or discharge home.

Main Outcomes and Measures

Physiological BPD was assessed at 36 weeks' postmenstrual age. IQ was assessed at 5 years' corrected age using the Wechsler Preschool and Primary Scale of Intelligence, 4th Edition; children from the 5 highest-recruiting Australian hospitals were assessed. The total effect of DHA supplementation on IQ was divided into direct and indirect effects using mediation analysis, with BPD as the presumed mediating variable.

Results

Among 656 surviving children from hospitals involved in IQ follow-up (mean [SD] gestational age at birth, 26.8 [1.4] weeks; 346 males [52.7%]), there were 323 children with DHA supplementation and 333 children in the control group. Mean IQ was 3.45 points (95% CI, 0.38 to 6.53 points) higher in the DHA group than the control group, despite an increase in the risk of BPD (160 children [49.7%] vs 143 children [42.8%] with BPD). The indirect effect of DHA on IQ via BPD was not statistically significant (-0.17 points; 95% CI, -0.62 to 0.13 points), with most of the effect of DHA on IQ occurring independently of BPD (direct effect = 3.62 points; 95% CI, 0.55 to 6.81 points).

Conclusions and Relevance

This study found that associations of DHA with BPD and IQ were largely independent. This finding suggests that if clinicians supplement children born preterm with high-dose DHA, any resulting increase in BPD risk would not be associated with meaningful reductions in the IQ benefit.

Prehospital Cardiovascular Autoregulatory Disturbances Correlate With the Functional Neuroanatomy of Acute Spinal Cord Injury

STUDY DESIGN

Retrospective study.

OBJECTIVE

The importance of attenuating the cardiovascular autoregulatory disturbances accompanying acute spinal cord injury (SCI) has long been recognized. This report assembles SCI emergency service data and correlates cardiovascular parameters to preserved functional neuroanatomy.

SUMMARY OF BACKGROUND DATA

The nascent nature of evidence-based reporting of prehospital cardiovascular autoregulatory disturbances in SCI indicates the need to assemble more information.

MATERIALS AND METHODS

SCI data for <24 hours were extracted from ambulance and hospital records. The mean arterial pressure (MAP) was calculated. The International Standard for Neurological Classification of SCI (ISNCSCI) evaluates the primary outcome of motor incomplete injury (grades C/D) at acute presentation. Logistic regression was adjusted for multiple confounders that were expected to influence the odds of grade C/D.

RESULTS

A cohort of 99 acute SCI cases was retained; mean (SD) age 40.7±20.5 years, 88 male, 84 tetraplegic, 65 grades A/B (motor complete injury), triage time 2±1.6 hours. The lowest recorded prehospital MAP [mean (SD): 77.9±19, range: 45-145 mm Hg] approached the nadir for adequate organ perfusion. Thirty-four (52%) grade A/B and 10 (30%) C/D cases had MAP readings <85 mm Hg. In data adjusted for age, injury level, and triage time a 5 mm Hg increase in the lowest MAP value was associated with a 34% increase in the odds of having motor incomplete injury at acute presentation (adjusted odds ratio=1.34; 95% CI: 1.11-1.61; P =0.002).

CONCLUSION

An important observation with implications for timely and selective cardiovascular resuscitation during SCI prehospital care involves significant negative associations between the depth of systemic hypotension and preserved functional neuroanatomy. Regardless of the mechanism, our confounder-adjusted logistic regression model extends in-hospital evidence and provides a conceptual bedside-bench framework for future investigations.

Neonatal Docosahexaenoic Acid in Preterm Infants and Intelligence at 5 Years

BACKGROUND

Docosahexaenoic acid (DHA) is a component of neural tissue. Because its accretion into the brain is greatest during the final trimester of pregnancy, infants born before 29 weeks' gestation do not receive the normal supply of DHA. The effect of this deficiency on subsequent cognitive development is not well understood.

METHODS

We assessed general intelligence at 5 years in children who had been enrolled in a trial of neonatal DHA supplementation to prevent bronchopulmonary dysplasia. In the previous trial, infants born before 29 weeks' gestation had been randomly assigned in a 1:1 ratio to receive an enteral emulsion that provided 60 mg of DHA per kilogram of body weight per day or a control emulsion from the first 3 days of enteral feeds until 36 weeks of postmenstrual age or discharge home, whichever occurred first. Children from 5 of the 13 centers in the original trial were invited to undergo assessment with the Wechsler Preschool and Primary Scale of Intelligence (WPPSI) at 5 years of corrected age. The primary outcome was the full-scale intelligence quotient (FSIQ) score. Secondary outcomes included the components of WPPSI.

RESULTS

A total of 1273 infants underwent randomization in the original trial; of the 656 surviving children who had undergone randomization at the centers included in this follow-up study, 480 (73%) had an FSIQ score available - 241 in the DHA group and 239 in the control group. After imputation of missing data, the mean (±SD) FSIQ scores were 95.4±17.3 in the DHA group and 91.9±19.1 in the control group (adjusted difference, 3.45; 95% confidence interval, 0.38 to 6.53; P = 0.03). The results for secondary outcomes generally did not support that obtained for the primary outcome. Adverse events were similar in the two groups.

CONCLUSIONS

In infants born before 29 weeks' gestation who had been enrolled in a trial to assess the effect of DHA supplementation on bronchopulmonary dysplasia, the use of an enteral DHA emulsion until 36 weeks of postmenstrual age was associated with modestly higher FSIQ scores at 5 years of age than control feeding. (Funded by the Australian National Health and Medical Research Council and Nu-Mega Ingredients; N3RO Australian New Zealand Clinical Trials Registry number, ACTRN12612000503820.).

Interventions to control children's screen use and their effect on sleep: A systematic review and meta-analysis

Prolonged viewing of screen-based media is associated with poor sleep in children. Previous systematic reviews have analysed the effectiveness of interventions that aim to limit children's screen use; however, none have evaluated its effect on sleep. The aim of this systematic review was to evaluate the effect of interventions that incorporate strategies to control children's screen use on screen use and sleep. The databases Pubmed, Embase, Eric, Scopus and PsycInfo were searched during October 2017 and updated in February 2019 for experimental studies with a control that assessed interventions to control screen use in children aged 2-14 years and reported both screen use and sleep outcomes. From 3,872 initial records, 11 studies (six randomized control [RCT], four cluster RCT and one cluster, quasi-experimental) were eligible for inclusion. A total of 4,656 children aged 2-13 years were included in the studies. The mean reduction in screen time was 0.56 hr (33 min)/day (95% confidence interval [CI], 0.92, 0.20) and the mean sleep duration increased by 0.19 hr (11 min)/day (95% CI, 0.05, 0.33). Bedtime was advanced by 0.16 hr (10 min) on weekdays and by 1.0 hr at the weekend. Subgroup analyses indicated stronger intervention effects for interventions of shorter duration (<3 months), which specifically targeted screen use or sleep, and those with direct participant contact. In conclusion, small improvements in screen time and sleep duration can be achieved in children. It is not possible to determine if a reduction in screen time directly improves sleep, due to the limited number of studies, the presence of co-interventions, issues with studies' methodological quality and heterogeneity.