Commentary - The late preterm infant: Vulnerable cerebral cortex and large burden of disability

Cerebral Ultrasound at Term-Equivalent Age: Correlations with Neuro-Motor Outcomes at 12-24 Months Corrected Age

Background/Objectives: Our research aimed to assess if correlations could be found between items evaluated at the cerebral ultrasound performed at term-equivalent age (TEA) and neuro-motor outcomes evaluated at 12 and 24 months of corrected age in a group of preterm infants. Methods: The following were assessed: the Levine Index, the diagonals of the lateral ventricles, the size of the ventricular midbody, the sinocortical distance, the width of the basal ganglia, the cortical depth at the level of the cingular sulcus and the maturation of the gyral folding. The neurologic evaluation was performed at 12 and 24 months of corrected age, according to the Amiel Tison neurologic examination, and the items from the calendar of motor acquisitions were used as outcome measures of the study-gross and fine motor subsets. The comparisons between the different groups were performed using the FANOVA test, with a statistically significant association for a p < 0.05. Results: The abnormal gross motor acquisitions at 12 months were significantly associated with an increased size of the ventricular midbody (p < 0.009) and a significantly decreased diameter of the basal ganglia (p < 0.011) on the TEA cerebral ultrasound. At 24 months, a significant association was found with increased size of the ventricular midbody (>10.33 mm) (p < 0.001), a decreased diameter of the basal ganglia (<12.9 mm) (p < 0.016), a decreased cortical depth (p < 0.021) and an immature gyral maturation pattern (p < 0.001). In the case of severely abnormal fine motor outcomes, at 12 months, there were statistically significant associations with an increased size of the ventricular midbody (p < 0.001) and an immature gyral folding pattern (p < 0.0180); at 24 months, significant associations were noted with the size of ventricular midbody (p < 0.001), a decreased diameter of the basal ganglia (p < 0.016), a decreased cortical depth (p < 0.021) and an immature gyration folding (p < 0.001). Conclusions: The abnormal gross and fine motor outcome in former premature infants at 12-24 months corrected age is significantly associated with abnormal findings in the head ultrasound examination performed at TEA reflecting both white matter (increased midbody distance) and grey matter (decreased diameter of the basal ganglia, decreased cortical depth and an immature gyration pattern) involvement.

Black women and the preemie prep for parents (P3) program: Exploratory analysis of a clinical trial

•Black women receiving the smartphone P3 program had more preterm birth knowledge.•Black women receiving the P3 program were more prepared for healthcare decisions.•Black women receiving the P3 program talked more with partners about preterm birth.•Smartphone preterm birth education may overcome clinic-based education barriers.

Single-Center Experience with Therapeutic Hypothermia for Hypoxic-Ischemic Encephalopathy in Infants with <36 Weeks' Gestation

OBJECTIVE

 Hypoxic-ischemic encephalopathy (HIE) is a leading cause of morbidity and mortality in neonates. Therapeutic hypothermia (TH) has improved outcomes and mortality in infants with >36 weeks' gestational age (GA) with moderate-to-severe HIE. There are limited data on the safety and efficacy of TH in preterm infants with HIE. This study describes our experience and examines the safety of TH in neonates with <36 weeks' GA.

STUDY DESIGN

A single-center, retrospective study of preterm neonates born at <36 weeks' GA with moderate-to-severe HIE and treated with TH, compared to a cohort of term neonates with HIE (≥37 weeks' GA), was conducted. The term cohort was matched for degree of background abnormality on electroencephalogram, sex, inborn versus outborn status, and birth year. Medical records were reviewed for pregnancy and delivery complications, need for transfusion, sedation and antiseizure medications, electroencephalography and imaging findings, and in-hospital mortality.

RESULTS

 Forty-two neonates born at <36 weeks' GA with HIE received TH between 2005 and 2022. Data from 42 term neonates were analyzed for comparison. The average GA of the preterm cohort was 34.6 weeks and 39.3 weeks for the term cohort. Apgar scores, degree of acidosis, and need for blood product transfusions were similar between groups. Preterm infants were more likely to require inotropic support (55 vs. 29%, p = 0.026) and hydrocortisone (36 vs. 12%, p = 0.019) for hypotension. The proportion of infants without evidence of injury on magnetic resonance imaging was similar in both groups: 43 versus 50% in preterm and term infants, respectively. No significant difference was found in mortality between groups.

CONCLUSION

 In this single-center cohort, TH in preterm infants appears to be as safe as in term infants, with no significant increase in intracranial bleeds or mortality. Preterm infants more frequently required inotropes and steroids for hypotension. Further research is needed to determine efficacy of TH in preterm infants.

KEY POINTS

· TH is used off-protocol in preterm infants.. · Preterm and term infants have similar mortality.. · Preterm cohort required more inotropic support..

Postnatal functional integrity of the brainstem auditory pathway in late preterm infants born of small-for-gestation age: how different from those born of appropriate-for-gestation

It is unclear whether there is any postnatal abnormality in brainstem auditory function in late preterm small-for-gestational-age (SGA) infants. We investigated the functional integrity of the brainstem auditory pathway at 4 months after term in late preterm SGA infants and defined differences from appropriate-for-gestational age (AGA) infants. The maximum length sequence brainstem evoked response (MLS BAER) was recorded and analyzed in 24 SGA (birthweight < 3rd centile) infants and 28 AGA infants (birthweight > 10th centile). All infants were born at 33-36-week gestation without major perinatal and postnatal problems. We found that I-V interval in SGA infants was shorter than in AGA infants at higher click rates and significantly shorter at the highest rate of 910/s. Of the two smaller intervals, I-III interval was significantly shorter in SGA infants than in AGA infants at higher click rates of 455 and 910/s clicks, whereas III-V interval was similar in the two groups. The III-V/I-III interval ratio in SGA infants tended to be greater than in AGA infants at all rates and was significantly greater at 455 and 910/s clicks. The slope of I-III interval-rate functions in SGA infants was moderately smaller than in AGA infants.  Conclusions: The main and fundamental difference between late preterm SGA and AGA infants was a significant shortening in the MLS BAER I-III interval in SGA infants at higher click rates, suggesting moderately faster neural conduction in the caudal brainstem regions. Postnatal neural maturation in the caudal brainstem regions is moderately accelerated in late preterm SGA infants. What is Known: • At 40 weeks of postconceptional age, late preterm SGA infants manifested a mild delay in neural conduction in the auditory brainstem. What is New: • At 56 weeks of postconceptional age, late preterm SGA infants manifested moderately faster neural conduction in the caudal brainstem regions. • Postnatal neural maturation is moderately accelerated in the caudal brainstem regions of late preterm SGA infants.

Lactoferrin intake from maternal milk during the neonatal hospitalization and early brain development among preterm infants

BACKGROUND

Lactoferrin is an immuno-modulatory nutrient in human milk that may be neuroprotective.

METHODS

In 36 infants born <32 weeks' gestation, we sampled human milk at 14 and 28 days of chronologic age and measured lactoferrin by electrochemiluminescence multiplex immunoassay. Using 3T quantitative brain magnetic resonance imaging scans obtained at term equivalent, we estimated total and regional brain volumes. We compared outcomes between infants exposed to low (bottom tertile, range 0.06-0.13 mg/mL) vs. high (top tertile, range 0.22-0.35 mg/mL) lactoferrin using median regression in models adjusted for gestational age, birth weight z-score, sex, and postmenstrual age.

RESULTS

Compared to infants exposed to low lactoferrin, infants exposed to high lactoferrin had 43.9 cc (95% CI: 7.6, 80.4) larger total brain volume, 48.3 cc (95% CI: 12.1, 84.6) larger cortical gray matter, and 3.8 cc (95% CI: 0.7, 7.0) larger deep gray matter volume at term equivalent age. Other regional brain volumes were not statistically different between groups.

CONCLUSION

Higher lactoferrin exposure during the neonatal hospitalization was associated with larger total brain and gray matter volumes, suggesting that lactoferrin may have potential as a dietary supplement to enhance brain growth in the neonatal intensive care unit setting.

IMPACT

This study suggests that lactoferrin, a whey protein found in human milk, may be beneficial for preterm infant brain development, and therefore has potential as a dietary supplement in the neonatal intensive care unit setting.

The Rat Brain Transcriptome: From Infancy to Aging and Sporadic Alzheimer's Disease-like Pathology

It has been suggested that functional traits of the adult brain-all of which are established early in life-may affect the brain's susceptibility to Alzheimer's disease (AD). Results of our previous studies on senescence-accelerated OXYS rats, a model of sporadic AD, support this hypothesis. Here, to elucidate the molecular genetic nature of the aberrations revealed during brain maturation, we analyzed transcriptomes (RNA-seq data) of the prefrontal cortex (PFC) and hippocampus of OXYS rats and Wistar (control) rats in the period of brain maturation critical for OXYS rats (ages P3 and P10; P: postnatal day). We found more than 1000 differentially expressed genes in both brain structures; functional analysis indicated reduced efficiency of the formation of neuronal contacts, presumably explained mainly by deficits of mitochondrial functions. Next, we compared differentially expressed genes in the rat PFC and hippocampus from infancy to the progressive stage of AD-like pathology (five ages in total). Three genes (Thoc3, Exosc8, and Smpd4) showed overexpression in both brain regions of OXYS rats throughout the lifespan. Thus, reduced efficiency of the formation of neural networks in the brain of OXYS rats in infancy likely contributes to the development of their AD-like pathology.

Associations between neurological examination at term-equivalent age and cerebral hemodynamics and oxygen metabolism in infants born preterm

Background

Infants born at 29-36 weeks gestational age (GA) are at risk of experiencing neurodevelopmental challenges. We hypothesize that cerebral hemodynamics and oxygen metabolism measured by bedside optical brain monitoring are potential biomarkers of brain development and are associated with neurological examination at term-equivalent age (TEA).

Methods

Preterm infants (N = 133) born 29-36 weeks GA and admitted in the neonatal intensive care unit were enrolled in this prospective cohort study. Combined frequency-domain near infrared spectroscopy (FDNIRS) and diffuse correlation spectroscopy (DCS) were used from birth to TEA to measure cerebral hemoglobin oxygen saturation and an index of microvascular cerebral blood flow (CBF _i ) along with peripheral arterial oxygen saturation (SpO₂). In combination with hemoglobin concentration in the blood, these parameters were used to derive cerebral oxygen extraction fraction (OEF) and an index of cerebral oxygen metabolism (CMRO_2i ). The Amiel-Tison and Gosselin Neurological Assessment was performed at TEA. Linear regression models were used to assess the associations between changes in FDNIRS-DCS parameters from birth to TEA and GA at birth. Logistic regression models were used to assess the associations between changes in FDNIRS-DCS parameters from birth to TEA and neurological examination at TEA.

Results

Steeper increases in CBF _i (p < 0.0001) and CMRO_2i (p = 0.0003) were associated with higher GA at birth. Changes in OEF, CBF _i , and CMRO_2i from birth to TEA were not associated with neurological examination at TEA.

Conclusion

In this population, cerebral FDNIRS-DCS parameters were not associated with neurological examination at TEA. Larger increases in CBF _i and CMRO_2i from birth to TEA were associated with higher GA. Non-invasive bedside FDNIRS-DCS monitoring provides cerebral hemodynamic and metabolic parameters that may complement neurological examination to assess brain development in preterm infants.