Early neurodevelopmental follow-up in the NICHD neonatal research network: Advancing neonatal care and outcomes, opportunities for the future

Neurodevelopmental Outcomes of Extremely Preterm Infants Fed Donor Milk or Preterm Infant Formula: A Randomized Clinical Trial

Importance

Maternal milk feeding of extremely preterm infants during the birth hospitalization has been associated with better neurodevelopmental outcomes compared with preterm formula. For infants receiving no or minimal maternal milk, it is unknown whether donor human milk conveys similar neurodevelopmental advantages vs preterm formula.

Objective

To determine if nutrient-fortified, pasteurized donor human milk improves neurodevelopmental outcomes at 22 to 26 months' corrected age compared with preterm infant formula among extremely preterm infants who received minimal maternal milk.

Design, Setting, and Participants

Double-blind, randomized clinical trial conducted at 15 US academic medical centers within the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network. Infants younger than 29 weeks 0 days' gestation or with a birth weight of less than 1000 g were enrolled between September 2012 and March 2019.

Intervention

Preterm formula or donor human milk feeding from randomization to 120 days of age, death, or hospital discharge.

Main Outcomes and Measures

The primary outcome was the Bayley Scales of Infant and Toddler Development (BSID) cognitive score measured at 22 to 26 months' corrected age; a score of 54 (score range, 54-155; a score of ≥85 indicates no neurodevelopmental delay) was assigned to infants who died between randomization and 22 to 26 months' corrected age. The 24 secondary outcomes included BSID language and motor scores, in-hospital growth, necrotizing enterocolitis, and death.

Results

Of 1965 eligible infants, 483 were randomized (239 in the donor milk group and 244 in the preterm formula group); the median gestational age was 26 weeks (IQR, 25-27 weeks), the median birth weight was 840 g (IQR, 676-986 g), and 52% were female. The birthing parent's race was self-reported as Black for 52% (247/478), White for 43% (206/478), and other for 5% (25/478). There were 54 infants who died prior to follow-up; 88% (376/429) of survivors were assessed at 22 to 26 months' corrected age. The adjusted mean BSID cognitive score was 80.7 (SD, 17.4) for the donor milk group vs 81.1 (SD, 16.7) for the preterm formula group (adjusted mean difference, -0.77 [95% CI, -3.93 to 2.39], which was not significant); the adjusted mean BSID language and motor scores also did not differ. Mortality (death prior to follow-up) was 13% (29/231) in the donor milk group vs 11% (25/233) in the preterm formula group (adjusted risk difference, -1% [95% CI, -4% to 2%]). Necrotizing enterocolitis occurred in 4.2% of infants (10/239) in the donor milk group vs 9.0% of infants (22/244) in the preterm formula group (adjusted risk difference, -5% [95% CI, -9% to -2%]). Weight gain was slower in the donor milk group (22.3 g/kg/d [95% CI, 21.3 to 23.3 g/kg/d]) compared with the preterm formula group (24.6 g/kg/d [95% CI, 23.6 to 25.6 g/kg/d]).

Conclusions and Relevance

Among extremely preterm neonates fed minimal maternal milk, neurodevelopmental outcomes at 22 to 26 months' corrected age did not differ between infants fed donor milk or preterm formula.

Trial Registration

ClinicalTrials.gov Identifier: NCT01534481.

Corrected Age at Bayley Assessment and Developmental Delay in Extreme Preterms

BACKGROUND AND OBJECTIVES

Research on outcomes of prematurity frequently examines neurodevelopment in the toddler years as an end point, but the age range at examination varies. We aimed to evaluate whether the corrected age (CA) at Bayley-III assessment is associated with rates of developmental delay in extremely preterm children.

METHODS

This retrospective cohort study included children born at <29 weeks' gestation who were admitted in the Canadian Neonatal Network between 2009 and 2017. The primary outcomes were significant developmental delay (Bayley-III score <70 in any domain) and developmental delay (Bayley-III score <85 in any domain). To assess the association between CA at Bayley-III assessment and developmental delay, we compared outcomes between 2 groups of children: those assessed at 18 to 20 months' CA and 21-24 months.

RESULTS

Overall, 3944 infants were assessed at 18-20 months' CA and 881 at 21-24 months. Compared with infants assessed at 18-20 months, those assessed at 21-24 months had higher odds of significant development delay (20.0% vs 12.5%; adjusted odds ratio, 1.75; 95% confidence interval [CI], 1.41-2.13) and development delays (48.9% vs 41.7%, adjusted odds ratio 1.33; 95% CI, 1.11-1.52). Bayley-III composite scores were on average 3 to 4 points lower in infants evaluated at 21-24 months' CA (for instance, adjusted mean difference and 95% CI for language: 3.49 [2.33-4.66]). Conversely, rates of cerebral palsy were comparable (4.6% vs 4.7%) between the groups.

CONCLUSIONS

Bayley-III assessments performed at 21-24 months' CA were more likely to diagnose a significant developmental delay compared with 18- to 20-month assessments in extremely preterm children.

Effect of biomedical complications on very and extremely preterm children's language

Introduction

Very and extremely preterm children have been found to show delays in the development of language in early years. In some investigations, however, a rigorous control of biomedical complications, such as Periventricular Leukomalacia (PVL), Intraventricular Hemorrhage (IVH) or Bronchopulmonary Dysplasia (BPD), does not always exist. For that reason, a confounding effect of low gestational age and biomedical complications may lead to erroneous conclusions about the effect of gestational age.

Methods

In this investigation we compare language development [use of words, sentence complexity and mean length of the three longest utterances (MLU3)] of three groups of Chilean children at 24 months of age (corrected age for preterm children). The first group was composed of 42 healthy full-term children (Full term group: FT), the second group of 60 preterm children born below 32 gestational weeks without medical complications (low risk preterm group: LRPT), and the third group was composed of 64 children below 32 gestational weeks who had medical complications (High risk preterm group: HRPT). The three groups were similar in terms of gender distribution, maternal education, and socio-economic environment. The instrument used to assess language was the Communicative Development Inventories (CDI). In addition, the Ages and Stages Questionnaire-3 (ASQ-3) was also used to assess other developmental dimensions.

Results

The results indicate that HRPT and LRPT children obtained significantly lower results than the FT group in the three language measures obtained through the CDI. No significant differences were observed between the HRPT and the LRPT groups, although the HRPT obtained the lowest results in the three CDI measures. The results obtained through the administration of the ASQ-3 confirm the delay of both preterm groups in communicative development when compared to the FT group. No significant differences between the FT and the PT groups were observed in gross motor, fine motor and problem solving dimensions of the ASQ-3. The LRPT group obtained results that were significantly higher than those of the FT group and the HRPT group in gross motor development.

Discussion

These results seem to indicate that the area of language development is particularly influenced by very or extremely low gestational age.