Neonatal Hemoglobin Levels in Preterm Infants Are Associated with Early Neurological Functioning

BACKGROUND

Neonatal anemia may compromise oxygen transport to the brain. The effects of anemia and cerebral oxygenation on neurological functioning in the early neonatal period are largely unknown.

OBJECTIVE

This study aimed to determine the association between initial hemoglobin levels (Hb) and early neurological functioning in preterm infants by assessing their general movements (GMs).

METHODS

A retrospective analysis of prospectively collected data on preterm infants born before 32 weeks of gestation was conducted. We excluded infants with intraventricular hemorrhage > grade II. On day 8, we assessed infants' GMs, both generally as normal/abnormal and in detail using the general movement optimality score (GMOS). We measured cerebral tissue oxygen saturation (rcSO2) on day 1 using near-infrared spectroscopy.

RESULTS

We included 65 infants (median gestational age 29.9 weeks [IQR 28.2-31.0]; median birth weight 1,180 g [IQR 930-1,400]). Median Hb on day 1 was 10.3 mmol/L (range 4.2-13.7). Lower Hb on day 1 was associated with a higher risk of abnormal GMs (OR = 2.3, 95% CI: 1.3-4.1) and poorer GMOSs (B = 0.9, 95% CI: 0.2-1.7). Hemoglobin strongly correlated with rcSO2 (rho = 0.62, p < 0.01). Infants with lower rcSO2 values tended to have a higher risk of abnormal GMs (p = 0.06). After adjusting for confounders, Hb on day 1 explained 44% of the variance of normal/abnormal GMs and rcSO2 explained 17%. Regarding the explained variance of the GMOS, this was 25% and 16%, respectively.

CONCLUSIONS

In preterm infants, low Hb on day 1 is associated with impaired neurological functioning on day 8, which is partly explained by low cerebral oxygenation.

Fetal Brain-Sparing, Postnatal Cerebral Oxygenation, and Neurodevelopment at 4 Years of Age Following Fetal Growth Restriction

Objectives: To assess the role of fetal brain-sparing and postnatal cerebral oxygen saturation (r_cSO₂) as determinants of long-term neurodevelopmental outcome following fetal growth restriction (FGR). Methods: This was a prospective follow-up study of an FGR cohort of 41 children. Prenatally, the presence of fetal brain-sparing (cerebroplacental ratio < 1) was assessed by Doppler ultrasound. During the first two days after birth, r_cSO₂ was measured with near-infrared spectroscopy. At 4 years of age, intelligence (IQ points), behavior (T-scores), and executive function (T-scores) were assessed using the Wechsler Preschool and Primary Scale of Intelligence, Child Behavior Checklist, and Behavior Rating Inventory of Executive Function-Preschool Version, respectively. Using linear regression analyses, we tested the association (p < 0.05) between brain-sparing/r_cSO₂ and normed neurodevelopmental scores. Results: Twenty-six children (gestational age ranging from 28.0 to 39.9 weeks) participated in the follow-up at a median age of 4.3 (range: 3.6 to 4.4) years. Autism spectrum disorder was reported in three children (11.5%). Fetal brain-sparing was associated with better total and externalizing behavior (betas: -0.519 and -0.494, respectively). R_cSO₂ levels above the lowest quartile, particularly on postnatal day 2 (≥ 77%), were associated with better total and internalizing behavior and executive functioning (betas: -0.582, -0.489, and -0.467, respectively), but also lower performance IQ (beta: -0.530). Brain-sparing mediated some but not all of these associations. Conclusions: In this FGR cohort, fetal brain-sparing and high postnatal r_cSO₂ were-independently, but also as a reflection of the same mechanism-associated with better behavior and executive function. Postnatal cerebral hyperoxia, however, was negatively associated with brain functions responsible for performance IQ.

Differential placental DNA methylation of VEGFA and LEP in small-for-gestational age fetuses with an abnormal cerebroplacental ratio

Background

In Fetal Growth Restriction ‘fetal programming’ may take place via DNA methylation, which has implications for short-term and long-term health outcomes. Small-for-gestational age fetuses are considered fetal growth restricted, characterized by brain-sparing when fetal Doppler hemodynamics are abnormal, expressed as a cerebroplacental ratio (CPR) <1. We aimed to determine whether brain-sparing is associated with altered DNA methylation of selected genes.

Methods

We compared DNA methylation of six genes in 41 small-for-gestational age placentas with a normal or abnormal CPR. We selected EPO, HIF1A, VEGFA, LEP, PHLDA2, and DHCR24 for their role in angiogenesis, immunomodulation, and placental and fetal growth. DNA methylation was analyzed by pyrosequencing.

Results

Growth restricted fetuses with an abnormal CPR showed hypermethylation of the VEGFA gene at one CpG (VEGFA-309, p = .001) and an overall hypomethylation of the LEP gene, being significant at two CpGs (LEP-123, p = .049; LEP-51, p = .020). No differences in methylation were observed for the other genes.

Conclusions

VEGFA and LEP genes are differentially methylated in placentas of small-for-gestational age fetuses with brain-sparing. Hypermethylation of VEGFA-309 in abnormal CPR-placentas could indicate successful compensatory mechanisms. Methylation of LEP-51 is known to suppress LEP expression. Hypomethylation in small-for-gestational age placentas with abnormal CPR may result in hyperleptinemia and predispose to leptin-resistance later in life.

Online versus offline spatiotemporal image correlation (STIC) M-mode for the evaluation of cardiac longitudinal annular displacement in fetal growth restriction

PURPOSE

Our first aim was to compare online M-mode with offline spatiotemporal image correlation (STIC) M-mode for assessing longitudinal annular displacement (LAD) in growth-restricted fetuses (FGR). Our second aim was to compare LAD measures of FGR cases with controls.

MATERIALS AND METHODS

Prospective study including 40 FGR cases (defined estimated fetal weight and birth weight <10th centile) and 72 normally grown fetuses matched to cases by gestational age at scan. LAD was measured with online M-mode and offline STIC M-mode at the left and right ventricular free walls and septum in all fetuses.

RESULTS

FGR cases had a significant decrease in LAD by STIC in all sites as compared to controls (e.g. right LAD in FGR mean 6.7 mm (SD 1.2) versus controls 7.2 mm (1.2), p = .033). There was a non-significant trend for lower values in FGR when using online M-mode (e.g. right LAD in FGR 6.9 mm (1.5) versus controls 7.4 mm (1.5), p = .084).

CONCLUSIONS

STIC M-mode seems a better method than online M-mode for detecting subtle changes in myocardial motion. STIC presents more precise results and allows an ideal placement of the M-mode arrow. These results confirm previous data suggesting decreased longitudinal motion in FGR.

Relationship between general movements in neonates who were growth restricted in utero and prenatal Doppler flow patterns

OBJECTIVE

To investigate whether Doppler pulsatility indices (PIs) of the fetal circulation in cases of fetal growth restriction (FGR) are associated with the general movements (GMs) of the neonate after birth.

METHODS

This was a prospective observational cohort study including pregnancies with FGR diagnosed between June 2012 and September 2014. A diagnosis of FGR was based on an abdominal circumference or estimated fetal weight < 10^th percentile (in conjuction with abnormal Doppler) or declining fetal growth of at least 30 percentiles with respect to previous size measurements. Doppler parameters of the umbilical artery (UA), fetal middle cerebral artery (MCA) and ductus venosus (DV) were measured maximally 1 week prior to delivery. Cerebroplacental ratio (CPR) was calculated as MCA-PI divided by UA-PI. We assessed the quality of neonatal GMs 7 days after birth, around the due date if cases were born preterm, and at 3 months post-term. We performed a detailed analysis of the motor repertoire by calculating a motor optimality score (MOS).

RESULTS

Forty-eight FGR cases were included with a median gestational age at delivery of 35 (range, 26-40) weeks. UA-PI, MCA-PI and CPR correlated strongly (ρ, -0.374 to 0.472; P < 0.01) with the MOS on day 7 after birth, but DV-PI did not. Doppler PI measurements did not correlate with MOS at 3 months post-term.

CONCLUSION

Fetal arterial Doppler measurements are associated with the quality of neonatal GMs 1 week after birth, but this association is no longer evident at 3 months post-term. Brain sparing in particular is associated strongly with GMs of an abnormal quality. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Correlation between Doppler flow patterns in growth-restricted fetuses and neonatal circulation

OBJECTIVES

To investigate whether prenatal Doppler parameters in growth-restricted fetuses are correlated with neonatal circulatory changes.

METHODS

In 43 cases of suspected fetal growth restriction (FGR), serial Doppler measurements of umbilical artery (UA) and middle cerebral artery (MCA) pulsatility index (PI) were performed. The last measurement, closest to delivery (< 1 week before birth), was used for analysis. Neonatal circulation was assessed for 2 h/day on Days 1-5, 8 and 15 by near-infrared spectroscopy (NIRS) of the cerebral, renal and splanchnic regions. We calculated fractional tissue oxygen extraction (FTOE) as: (arterial oxygen saturation - NIRS value)/arterial oxygen saturation. The following ratios were calculated: cerebroplacental ratio (CPR; MCA-PI/UA-PI), cerebrorenal ratio (CRR; cerebral/renal FTOE) and cerebrosplanchnic ratio (CSR; cerebral/splanchnic FTOE). Spearman's rank correlation coefficient (ρ) was calculated between prenatal Doppler parameters and neonatal NIRS variables. These analyses were carried out for the entire group, and separately for cases of early FGR (delivered < 34 weeks) and late FGR (≥ 34 weeks).

RESULTS

Fetal Doppler parameters correlated with neonatal NIRS variables on Days 1-3: UA-PI correlated with renal FTOE (Day 1: ρ = 0.454, P < 0.01) and CRR (Day 1: ρ = -0.517, P < 0.001). MCA-PI correlated with cerebral FTOE on Day 2 (ρ = 0.469, P < 0.01), approached statistical significance on Day 3 but was not correlated on Day 1. CPR correlated with CRR (Day 1: ρ = 0.474, P < 0.01). Most associations lost their statistical significance when early and late FGR subgroups were considered separately.

CONCLUSION

Low MCA-PI and low CPR, indicating brain sparing before birth, are associated with low CRR after birth, indicating relatively greater blood flow to the cerebrum than to the renal region. Based on the results of this study, it could be speculated that if brain sparing is present in the fetal circulation, it persists during the first 3 days after birth. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

A Hemodynamically Significant Patent Ductus Arteriosus Does Not Affect Cerebral or Renal Tissue Oxygenation in Preterm Infants

BACKGROUND

Patent ductus arteriosus (PDA) is common in preterm infants and is associated with significant morbidity. To determine whether the PDA is hemodynamically significant (HSDA), several echocardiographic parameters have been suggested, including retrograde diastolic blood flow in the descending aorta (Dao).

OBJECTIVE

To assess the impact of an HSDA, including retrograde diastolic flow in the Dao, on regional tissue oxygen saturation (rSO2) and extraction measured by near-infrared spectroscopy (NIRS).

METHODS

This is a prospective observational cohort study in which we included preterm infants (GA <32 weeks) who underwent echocardiographic screening because of clinical signs of an HSDA within 2 weeks after birth. We measured cerebral and renal rSO2 on the day of echocardiography. HSDA was diagnosed if left-to-right shunting through the PDA was accompanied by left atrial-to-aortic root ratio >1.4 and/or left pulmonary artery end-diastolic flow velocity >0.2 m/s and/or retrograde diastolic blood flow in the Dao.

RESULTS

Forty-nine infants were included, with a median GA of 27.6 weeks (IQR: 26.1-29.0), birth weight of 980 g (IQR: 800-1,200), and postnatal age of 77 h (IQR: 70-107). Infants with a closed duct (n = 11), a non-HSDA (n = 18), and an HSDA (n = 20) had similar cerebral and renal NIRS measurements. Retrograde diastolic blood flow in the Dao, present in 11 infants with PDA, also did not affect cerebral and renal NIRS measurements.

CONCLUSION

In preterm infants with clinical signs of an HSDA within 2 weeks after birth, cerebral and renal oxygen saturation and extraction are not affected by an HSDA or by retrograde diastolic blood flow in the Dao.

Functional outcomes at age 7 years of moderate preterm and full term children born small for gestational age

OBJECTIVE

To compare functional outcomes of 7-year-old (school-age) children born small for gestational age (SGA; ie, a birth weight z score ≤ -1 SD), with appropriate for gestational age (AGA) peers, born moderately preterm or full term.

STUDY DESIGN

Data were collected as part of the Longitudinal Preterm Outcome Project study, a community-based, prospective cohort study of 336 AGA and 42 SGA born children (median gestational age 35 weeks, range 31-41). Of the SGA children, 32 were moderately preterm, 10 were full term; of the AGA, these numbers were 216 and 120, respectively. At 6.9 years, we assessed intelligence, verbal memory, attention, visuomotor integration, and motor skills and we collected the parent-reported executive functioning. We compared the outcomes of the SGA children with those of their AGA peers.

RESULTS

The performance of SGA children was similar to that of their AGA peers, except for attention control which was abnormal more often in SGA children (OR 3.99, 95% CI 1.32-12.12). The IQ of SGA children was 3 points lower, but this difference failed to reach significance.

CONCLUSIONS

At school age, children born SGA have a greater risk of abnormal test scores on attention control than children born AGA, independent of gestational age. Their motor and many other cognitive functions are similar. The impact of these outcomes seems limited. Nevertheless, the consequences for school performance deserve attention.

Development of fine motor skills in preterm infants

Fine motor skills are related to functioning in daily life and at school. We reviewed the status of knowledge, in preterm children, on the development of fine motor skills, the relation with gross motor skills, and risk factors for impaired fine motor skills. We searched the past 15 years in PubMed, using ['motor skills' or 'fine motor function' and 'preterm infant'] as the search string. Impaired gross and fine motor skills are among the most frequently occurring problems encountered by preterm children who do not develop cerebral palsy. The prevalence is around 40% for mild to moderate impairment and 20% for moderate impairment. Fine motor skill scores on the Movement Assessment Battery for Children are about 0.62 of a standard deviation lower compared with term children. Risk factors for fine motor impairments include moderately preterm birth (odds ratio [OR] 2.0) and, among very preterm children (<32 wk gestation), intra-uterine growth restriction (ORs 2-3), inflammatory conditions (late-onset sepsis and necrotizing enterocolitis, ORs 3-5), and dexamethasone therapy for bronchopulmonary dysplasia (OR 2.7). A better understanding of factors that play a role in the development of and recovery from brain injury could guide future intervention attempts aimed at improving fine motor skills of preterm children.

Functional impairments at school age of children with necrotizing enterocolitis or spontaneous intestinal perforation

We aimed to determine motor, cognitive, and behavioral outcome at school age of children who had either necrotizing enterocolitis (NEC) or spontaneous intestinal perforation (SIP). This case-control study included infants with NEC Bell's stage IIA onward, infants with SIP, and matched controls (1996-2002). At school age, we assessed motor skills, intelligence, visual perception, visuomotor integration, verbal memory, attention, behavior, and executive functions. Of 93 infants with NEC or SIP, 28 (30%) died. We included 52 of 65 survivors for follow-up. At mean age of 9 y, we found that 68% of the children had borderline or abnormal scores on the Movement Assessment Battery for Children (versus 45% of controls). Their mean total intelligence quotient (IQ) was 86 ± 14 compared with 97 ± 9 in the controls. In addition, attention and visual perception were affected (p < 0.01 and p = 0.02). In comparison to controls, surgically treated children were at highest risk for adverse outcome. In conclusion, at school age, the motor functions and intelligence of many children with NEC or SIP were borderline or abnormal and, specifically, attention and visual perception were impaired. Children with NEC or SIP form a specific risk group for functional impairments at school age even though the majority does not have overt brain pathology.