Mortality and significant neurosensory impairment in preterm infants: an international comparison

Early hypophosphataemia and refeeding syndrome in extremely low birthweight babies and outcomes to 2 years of age: secondary cohort analysis from the ProVIDe trial

OBJECTIVE

To investigate in extremely low birthweight (ELBW; <1000 g) babies the associations between refeeding syndrome (serum phosphate <1.4 mmol·L-1 and serum total calcium>2.8 mmol·L-1) and hypophosphataemia in the first week and death or neurodisability at 2 years' corrected age (CA).

DESIGN

Secondary cohort analysis of the ProVIDe trial participants with serum biochemistry within 7 days of birth. At 2 years' CA, neurodisability was assessed by Bayley Scales of Infant Development Edition III and neurological examination. Associations between neurodisability and other variables were analysed using t-tests and logistic regression adjusted for sex and smallness-for-gestational age.

SETTING

Six tertiary neonatal intensive care units (NICUs) in New Zealand.

PARTICIPANTS

352 ELBW babies born between 29 April 2014 and 30 October 2018.

MAIN OUTCOME MEASURE

Death or neurodisability at 2 years' CA.

RESULTS

Fifty-nine babies died, two after discharge from the NICU. Of the 336 babies who survived to 2 years' CA, 277 had neurodevelopmental assessment and 107 (39%) had a neurodisability. Death or neurodisability was more likely in babies who had refeeding syndrome (aOR 1.96 (95% CI 1.09 to 3.53), p=0.02) and in babies who had hypophosphataemia (aOR 1.74 (95% CI 1.09 to 2.79), p=0.02). Hypophosphataemia was associated with increased risk of death (aOR 2.07 (95% CI 1.09 to 3.95), p=0.03)) and severe hypophosphataemia (<0.9 mmol·L-1) with increased risk of death (aOR 2.67 (95% CI 1.41 to 5.00), p=0.002) and neurodisability (aOR 2.31 (95% CI 1.22 to 4.35), p=0.01).

CONCLUSIONS

In ELBW babies, refeeding syndrome and hypophosphataemia in the first week are associated with death or neurodisability. Until optimal phosphate requirements are determined through further research, monitoring for hypophosphataemia and mitigation strategies are indicated.

TRIAL REGISTRATION NUMBER

ACTRN12612001084875.

Apgar Score and Neurodevelopmental Outcomes at Age 5 Years in Infants Born Extremely Preterm

Importance

The Apgar score is used worldwide as an assessment tool to estimate the vitality of newborns in their first minutes of life. Its applicability to estimate neurodevelopmental outcomes in infants born extremely preterm (EPT; <28 weeks' gestation) is not well established.

Objective

To investigate the association between the Apgar score and neurodevelopmental outcomes in infants born EPT.

Design, Setting, and Participants

This cohort study was conducted using data from the Effective Perinatal Intensive Care in Europe-Screening to Improve Health in Very Preterm Infants in Europe (EPICE-SHIPS) study, a population-based cohort in 19 regions of 11 European countries in 2011 to 2012. Clinical assessments of cognition and motor function at age 5 years were performed in infants born EPT and analyzed in January to July 2023.

Exposures

Apgar score at 5 minutes of life categorized into 4 groups (0-3, 4-6, 7-8, and 9-10 points).

Main Outcomes and Measures

Cognitive and motor outcomes were assessed using the Wechsler Preschool and Primary Scale of Intelligence test of IQ derived from locally normed versions by country and the Movement Assessment Battery for Children-Second Edition. Parents additionally provided information on communication and problem-solving skills using the Ages and Stages Questionnaire, third edition (ASQ-3). All outcomes were measured as continuous variables.

Results

From the total cohort of 4395 infants born EPT, 2522 infants were live born, 1654 infants survived to age 5 years, and 996 infants (478 females [48.0%]) followed up had at least 1 of 3 outcome measures. After adjusting for sociodemographic variables, perinatal factors, and severe neonatal morbidities, there was no association of Apgar score with IQ, even for scores of 3 or less (β = -3.3; 95% CI, -10.5 to 3.8) compared with the score 9 to 10 category. Similarly, no association was found for ASQ-3 (β = -2.1; 95% CI, -24.6 to 20.4). Congruent results for Apgar scores of 3 or less were obtained for motor function scores for all children (β = -4.0; 95% CI, -20.1 to 12.1) and excluding children with a diagnosis of cerebral palsy (β = 0.8, 95% CI -11.7 to 13.3).

Conclusions and Relevance

This study found that low Apgar scores were not associated with longer-term outcomes in infants born EPT. This finding may be associated with high interobserver variability in Apgar scoring, reduced vitality signs and poorer responses to resuscitation after birth among infants born EPT, and the association of more deleterious exposures in the neonatal intensive care unit or of socioeconomic factors with greater changes in outcomes during the first 5 years of life.

Cumulative risk factors contributing to hearing loss in preterm infants

OBJECTIVE

To investigate individual and concomitant risk factors for hearing loss during neonatal care.

DESIGN

Case-control study.

SETTING

Community.

POPULATION

237 children born <32 weeks of gestation; 57 with hearing loss and 180 with normal hearing born between 2009 and 2013, matched for sex, gestation and year of birth.

MAIN OUTCOME MEASURES

Data were abstracted from clinical records for overall risk factors daily for the first 14 days and then weekly until discharge from neonatal care. All infants were screened for the presence of m.1555A>G mutation.

RESULTS

Children with hearing loss had lower birth weight for gestational age, more severe neonatal illness, with increased exposure to inotrope, steroid, gentamicin, vancomycin and furosemide, and more frequent physiological risk, elevated bilirubin and creatinine levels and acidosis, but no index child was found to have the m.1555A>G mutation, compared with one among controls. The duration of gentamicin, vancomycin or furosemide administration in the first 14 days was associated with impaired hearing (OR per dose: 1.25; 95% CI 1.14 to 1.38). Multivariate analyses revealed independent risks for hearing loss for each day when there was physiological risk (OR per day 1.15 (1.05 to 1.27)) and each day of medication exposure (OR 1.23 (1.1 to 1.37)).

CONCLUSION

Although the relative contribution of underlying illness and medication cannot be identified by this study, cumulative use of ototoxic medication and the presence of physiologic risk factors independently increased the likelihood of hearing loss, warranting close monitoring of coincident therapy throughout neonatal critical care.

Early Amino Acids in Extremely Preterm Infants and Neurodisability at 2 Years

BACKGROUND

Whether higher parenteral amino acid intake improves outcomes in infants with extremely low birth weight is unclear.

METHODS

In this multicenter, parallel-group, double-blind, randomized, placebo-controlled trial, we assigned infants with birth weights of less than 1000 g at 8 neonatal intensive care units to receive amino acids at a dose of 1 g per day (intervention group) or placebo in addition to usual nutrition for the first 5 days after birth. The primary outcome was survival free from neurodisability as assessed with the Bayley Scales of Infant and Toddler Development and neurologic examination at 2 years, corrected for gestational age at birth. Secondary outcomes were the components of the primary outcome as well as the presence or absence of neonatal disorders, the rate of growth, and nutritional intake.

RESULTS

We enrolled 434 infants (217 per group) in this trial. Survival free from neurodisability was observed in 97 of 203 children (47.8%) in the intervention group and in 102 of 205 (49.8%) in the placebo group (adjusted relative risk, 0.95; 95% confidence interval [CI], 0.79 to 1.14; P = 0.56). Death before the age of 2 years occurred in 39 of 217 children (18.0%) in the intervention group and 42 of 217 (19.4%) in the placebo group (adjusted relative risk, 0.93; 95% CI, 0.63 to 1.36); neurodisability occurred in 67 of 164 children (40.9%) in the intervention group and 61 of 163 (37.4%) in the placebo group (adjusted relative risk, 1.16; 95% CI, 0.90 to 1.50). Neurodisability was moderate to severe in 27 children (16.5%) in the intervention group and 14 (8.6%) in the placebo group (adjusted relative risk, 1.95; 95% CI, 1.09 to 3.48). More children in the intervention group than in the placebo group had patent ductus arteriosus (adjusted relative risk, 1.65; 95% CI, 1.11 to 2.46). In a post hoc analysis, refeeding syndrome occurred in 42 of 172 children in the intervention group and 26 of 166 in the placebo group (adjusted relative risk, 1.64; 95% CI, 1.09 to 2.47). Eight serious adverse events occurred.

CONCLUSIONS

In infants with extremely low birth weight, extra parenteral amino acids at a dose of 1 g per day for 5 days after birth did not increase the number who survived free from neurodisability at 2 years. (Funded by the New Zealand Health Research Council and others; ProVIDe Australian New Zealand Clinical Trials Registry number, ACTRN12612001084875.).