Prethreshold retinopathy in premature infants with intrauterine growth restriction

Development of a joint set of database parameters for the EU-ROP and Fight Childhood Blindness! ROP Registries

BACKGROUND/AIMS

The incidence of retinopathy of prematurity (ROP) is increasing and treatment options are expanding, often without accompanying safety data. We aimed to define a minimal, patient-centred data set that is feasible to collect in clinical practice and can be used collaboratively to track and compare outcomes of ROP treatment with a view to improving patient outcomes.

METHODS

A multinational group of clinicians and a patient representative with expertise in ROP and registry development collaborated to develop a data set that focused on real-world parameters and outcomes that were patient centred, minimal and feasible to collect in routine clinical practice.

RESULTS

For babies receiving ROP treatment, we recommend patient demographics, systemic comorbidities, ROP status, treatment details, ophthalmic and systemic complications of treatment, ophthalmic and neurodevelopmental outcomes at initial treatment, any episodes of retreatment and follow-up examinations in the short and long-term to be collected for use in ROP studies, registries and routine clinical practice.

CONCLUSIONS

We recommend these parameters to be used in registries and future studies of ROP treatment, to reduce the variation seen in previous reports and allow meaningful assessments and comparisons. They form the basis of the EU-ROP and the Fight Childhood Blindness! ROP Registries.

Role of the brain-sparing effect on retinopathy of prematurity in newborns with fetal growth restriction

INTRODUCTION

This study aimed to investigate the role of the brain-sparing effect (BSE) on retinopathy of prematurity (ROP) in fetal growth restriction (FGR).

METHODS

In this retrospective study, 127 pregnant women were divided into two groups considering the cerebroplacental ratio (CPR): FGR with abnormal CPR group (n = 74) and the appropriate for gestational age with normal Doppler group (n = 53). CPR was computed using the pulsatility index (PI) and resistance index (RI) to quantitate the waveforms [middle cerebral artery (MCA) PI/umbilical artery (UA) PI and MCA RI/UA RI: a result <1 was taken into account as abnormal]. ROP screening results of newborns were recorded from electronic files.

RESULTS

After adjusting for co-variants, BSE was not related to ROP (adjusted odds ratio [aOR], 1.06; 95% confidence interval [CI], 0.23-4.95). Gestational age at delivery <30 weeks (aOR, 2.55; 95% CI, 1.04-6.93) and birth weight <1500 g (aOR, 5.15; 95% CI, 1.15-25.2) were independently associated with ROP. Preeclampsia, emergency cesarean section birth, or 48 h completion after the first steroid administration were not associated with ROP.

CONCLUSIONS

Gestational age at delivery <30 weeks and birth weight <1500 g are independent risk factors for ROP in FGR whereas the BSE is not a risk factor.

Platelet Counts and Risk of Severe Retinopathy of Prematurity: A Bayesian Model-Averaged Meta-Analysis

BACKGROUND

We aimed to conduct a systematic review and Bayesian model-averaged meta-analysis (BMA) on the association between platelet counts and severe retinopathy of prematurity (ROP).

METHODS

We searched for studies reporting on platelet counts (continuous variable) or thrombocytopenia (categorical variable) and severe ROP or aggressive posterior ROP (APROP). The timing of platelet counts was divided into Phase 1 (<2 weeks) and Phase 2 (around ROP treatment). BMA was used to calculate Bayes factors (BFs). The BF10 is the ratio of the probability of the data under the alternative hypothesis (H1) over the probability of the data under the null hypothesis (H0).

RESULTS

We included 21 studies. BMA showed an association between low platelet counts and severe ROP. The evidence was strong (BF10 = 13.5, 7 studies) for phase 1 and very strong (BF10 = 51.0, 9 studies) for phase 2. Thrombocytopenia (<100 × 109/L) in phase 2 was associated with severe ROP (BF10 = 28.2, 4 studies). Following adjustment for publication bias, only the association of severe ROP with thrombocytopenia remained with moderate evidence in favor of H1 (BF10 = 4.30).

CONCLUSIONS

Thrombocytopenia is associated with severe ROP. However, the evidence for this association was tempered when results were adjusted for publication bias.

Small for gestational age at preterm birth identifies adverse neonatal outcomes more reliably than antenatal suspicion of fetal growth restriction

BACKGROUND

Fetal growth restriction (FGR) is an important reason for premature delivery and a leading cause of perinatal morbidity and mortality. We aimed to evaluate whether classification as small for gestational age (SGA; <10th centile) at birth or antenatal suspicion of FGR was more strongly associated with neonatal morbidity and mortality in preterm infants.

METHODS

A retrospective audit of infants born between 24 + 0 and 32 + 6 weeks of gestation from 2012-2019 and admitted to the Neonatal Unit at Mercy Hospital for Women (MHW). Infants were categorized according to whether FGR was listed as an antenatal complication in the medical records and whether they were SGA (<10th centile on Fenton chart) or appropriate for gestational age (AGA) at birth, and comparisons for neonatal outcomes were made.

RESULTS

371/2126 preterm infants (17.5%) had antenatal suspicion of FGR, and 166 (7.8%) were SGA at birth. No differences in any neonatal outcomes were found between infants with or without suspected FGR, except decreased intraventricular hemorrhage (IVH) in the FGR group. SGA classification was associated with increased rates of all morbidities other than IVH, including bronchopulmonary dysplasia, retinopathy of prematurity, and necrotizing enterocolitis, compared with the AGA group. Death was significantly higher in the SGA group (7.2%) compared with the AGA group (3.5%).

CONCLUSION

SGA by Fenton chart more reliably identified neonates at risk of adverse neonatal outcomes than antenatal suspicion of FGR, suggesting it is a reasonable clinical proxy. This most likely reflects the much lower tenth centile weight cutoffs on the Fenton charts compared to in-utero charts used antenatally to diagnose FGR based on ultrasound estimated fetal weight. SGA classification by Fenton approximately equates to <3rd centile on in-utero charts at our institution, therefore identifying the most severe FGR cases.

Association of small for gestational age with retinopathy of prematurity: a systematic review and meta-analysis

CONTEXT

The association between small for gestational age (SGA) and retinopathy of prematurity (ROP) is unclear.

OBJECTIVE

A systematic review and meta-analysis was conducted to evaluate the association between ROP and SGA in preterm infants <37 weeks' gestational age (GA) admitted to neonatal intensive care unit.

METHODS

Medline, PubMed, Web of Science and Cochrane Central databases were searched from inception through 15 January 2019. Studies reporting outcomes based on SGA as the primary exposure variable were included. Data were extracted independently by two coauthors. Modified Newcastle-Ottawa scale was used for risk of bias assessment.

RESULTS

Database search yielded 536 records (Medline=152, PubMed=171, Web of Science=144 and Cochrane Central=69). Twenty-one studies evaluating 190 946 infants were included. SGA was associated with significantly higher odds of any stage of ROP on unadjusted analysis (unadjusted OR (uOR) 1.55; 95% CI 1.22 to 1.98; 10 studies) but not on adjusted analysis (adjusted OR (aOR) 2.16; 95% CI 0.66 to 7.11; 3 studies). SGA was associated with significantly higher odds of severe ROP (aOR 1.92; 95% CI 1.57 to 2.34; nine studies). SGA was also significantly associated with higher odds of treated ROP (aOR 1.39; 95% CI 1.18 to 1.65; three studies). In subgroup analysis of infants <29 weeks' GA, SGA was significantly associated with increased odds of ROP (uOR 1.64; 95% CI 1.19 to 2.26; two studies), severe ROP (aOR 1.61; 95% CI 1.23 to 2.10; four studies) and treated ROP (aOR 1.37; 95% CI 1.16 to 1.62; two studies).

CONCLUSION

SGA was associated with increased odds of any stage of ROP, severe ROP and treated ROP in preterm infants. Neonatologists should incorporate SGA into the risk assessment during ROP evaluation and while providing counselling to the families of preterm SGA infants. ROP screening guidelines should look into the frequency of follow-up examination in SGA infants in aim to offer early detection and treatment.

Early Postnatal IGF-1 and IGFBP-1 Blood Levels in Extremely Preterm Infants: Relationships with Indicators of Placental Insufficiency and with Systemic Inflammation

OBJECTIVE

To evaluate to what extent indicators of placenta insufficiency are associated with low concentrations of insulin-like growth factor 1 (IGF-1) and IGF-1-binding protein-1 (IGFBP-1) in neonatal blood, and to what extent the concentrations of these growth factors are associated with concentrations of proteins with inflammatory, neurotrophic, or angiogenic properties.

STUDY DESIGN

Using multiplex immunoassays, we measured the concentrations of IGF-1 and IGFBP-1, as well as 25 other proteins in blood spots collected weekly from ≥ 880 infants born before the 28th week of gestation, and sought correlates of concentrations in the top and bottom quartiles for gestational age and day the specimen was collected.

RESULTS

Medically indicated delivery and severe fetal growth restriction (sFGR) were associated with low concentrations of IGF-1 on the first postnatal day and with high concentrations of IGFBP-1 on almost all days. Elevated concentrations of IGF-1 and IGFBP-1 were accompanied by elevated concentrations of many other proteins with inflammatory, neurotrophic, or angiogenic properties.

CONCLUSION

Disorders associated with impaired placenta implantation and sFGR appear to account for a relative paucity of IGF-1 on the first postnatal day. Elevated concentrations of IGF-1 and especially IGFBP-1 were associated with same-day elevated concentrations of inflammatory, neurotrophic, and angiogenic proteins.

Neonatal Morbidities of Fetal Growth Restriction: Pathophysiology and Impact

Being born small lays the foundation for short-term and long-term implications for life. Intrauterine or fetal growth restriction describes the pregnancy complication of pathological reduced fetal growth, leading to significant perinatal mortality and morbidity, and subsequent long-term deficits. Placental insufficiency is the principal cause of FGR, which in turn underlies a chronic undersupply of oxygen and nutrients to the fetus. The neonatal morbidities associated with FGR depend on the timing of onset of placental dysfunction and growth restriction, its severity, and the gestation at birth of the infant. In this review, we explore the pathophysiological mechanisms involved in the development of major neonatal morbidities in FGR, and their impact on the health of the infant. Fetal cardiovascular adaptation and altered organ development during gestation are principal contributors to postnatal consequences of FGR. Clinical presentation, diagnostic tools and management strategies of neonatal morbidities are presented. We also present information on the current status of targeted therapies. A better understanding of neonatal morbidities associated with FGR will enable early neonatal detection, monitoring and management of potential adverse outcomes in the newborn period and beyond.

Intrauterine growth restriction decreases NF-κB signaling in fetal pulmonary artery endothelial cells of fetal sheep

Intrauterine growth restriction (IUGR) in premature newborns increases the risk for bronchopulmonary dysplasia, a chronic lung disease characterized by disrupted pulmonary angiogenesis and alveolarization. We previously showed that experimental IUGR impairs angiogenesis; however, mechanisms that impair pulmonary artery endothelial cell (PAEC) function are uncertain. The NF-κB pathway promotes vascular growth in the developing mouse lung, and we hypothesized that IUGR disrupts NF-κB-regulated proangiogenic targets in fetal PAEC. PAECs were isolated from the lungs of control fetal sheep and sheep with experimental IUGR from an established model of chronic placental insufficiency. Microarray analysis identified suppression of NF-κB signaling and significant alterations in extracellular matrix (ECM) pathways in IUGR PAEC, including decreases in collagen 4α1 and laminin α4, components of the basement membrane and putative NF-κB targets. In comparison with controls, immunostaining of active NF-κB complexes, NF-κB-DNA binding, baseline expression of NF-κB subunits p65 and p50, and LPS-mediated inducible activation of NF-κB signaling were decreased in IUGR PAEC. Although pharmacological NF-κB inhibition did not affect angiogenic function in IUGR PAEC, angiogenic function of control PAEC was reduced to a similar degree as that observed in IUGR PAEC. These data identify reductions in endothelial NF-κB signaling as central to the disrupted angiogenesis observed in IUGR, likely by impairing both intrinsic PAEC angiogenic function and NF-κB-mediated regulation of ECM components necessary for vascular development. These data further suggest that strategies that preserve endothelial NF-κB activation may be useful in lung diseases marked by disrupted angiogenesis such as IUGR.

Antecedents of Screening Positive for Attention Deficit Hyperactivity Disorder in Ten-Year-Old Children Born Extremely Preterm

BACKGROUND

The incidence of attention deficit hyperactivity disorder is higher among children born very preterm than among children who are mature at birth.

METHODS

We studied 583 ten-year-old children who were born before 28 weeks of gestation whose IQ was above 84 and had a parent-completed Child Symptom Inventory-4, which allowed classification of the child as having or not having symptoms of attention deficit hyperactivity disorder. For 422 children, we also had a teacher report, and for 583 children, we also had a parent report of whether or not a physician made an attention deficit hyperactivity disorder diagnosis.

RESULTS

The risk profile of screening positive for attention deficit hyperactivity disorder based on a parent's report differed from the risk profile based on the teacher's report, whereas the risk profile according to a physician and according to any two observers closely resembled the parent-reported profile. Among the statistically significant risk factors were young maternal age (parent, physician, and two observers), maternal obesity (parent, physician, and two observers), maternal smoking (parent, physician, and two observers), magnesium given at delivery for seizure prophylaxis (parent and two observers), recovery of Mycoplasma sp. from the placenta (teacher and two observers), low gestational age (parent and two observers), low birth weight (teacher and physician), singleton (parent, physician, and two observers), male (parent, teacher, physician, and two observers), mechanical ventilation on postnatal day seven (physician), receipt of a sedative (parent and two observers), retinopathy of prematurity (parent), necrotizing enterocolitis (physician), antibiotic receipt (physician and two observers), and ventriculomegaly on brain scan (parent and two observers).

CONCLUSIONS

The multiplicity of risk factors identified can be subsumed as components of four broad themes: low socioeconomic state, immaturity or vulnerability, inflammation, and epigenetic phenomena.

Systemic Inflammation-Associated Proteins and Retinopathy of Prematurity in Infants Born Before the 28th Week of Gestation

Purpose

To assess the association between systemic levels of inflammation-associated proteins and severe retinopathy of prematurity (ROP) in extremely preterm infants.

Methods

We collected whole blood on filter paper on postnatal days 1, 7, 14, 21, and 28 from 1205 infants born before the 28th week of gestation, and measured the concentrations of 27 inflammation-associated, angiogenic, and neurotrophic proteins. We calculated odds ratios with 95% confidence intervals for the association between top quartile concentrations of each protein and prethreshold ROP.

Results

During the first three weeks after birth, high concentrations of VEGF-R1, myeloperoxidase (MPO), IL-8, intercellular adhesion molecule (ICAM)-1, matrix metalloproteinase 9, erythropoietin, TNF-α, and basic fibroblast growth factor were associated with an increased risk for prethreshold ROP. On day 28, high levels of serum amyloid A, MPO, IL-6, TNF-α, TNF-R1/-R2, IL-8, and ICAM-1 were associated with an increased risk. Top quartile concentrations of the proinflammatory cytokines TNF-α and IL-6 were associated with increased risks of ROP when levels of neuroprotective proteins and growth factors, including BDNF, insulin-like growth factor 1, IGFBP-1, VEGFR-1 and -2, ANG-1 and PlGF, were not in the top quartile. In contrast, high concentrations of NT-4 and BDNF appeared protective only in infants without elevated inflammatory mediators.

Conclusions

Systemic inflammation during the first postnatal month was associated with an increased risk of prethreshold ROP. Elevated concentrations of growth factors, angiogenic proteins, and neurotrophins appeared to modulate this risk, and were capable of reducing the risk even in the absence of systemic inflammation.

Extremely low gestational age and very low birthweight for gestational age are risk factors for autism spectrum disorder in a large cohort study of 10-year-old children born at 23-27 weeks' gestation

BACKGROUND

No prospective cohort study of high-risk children has used rigorous exposure assessment and optimal diagnostic procedures to examine the perinatal antecedents of autism spectrum disorder separately among those with and without cognitive impairment.

OBJECTIVE

We sought to identify perinatal factors associated with increased risk for autism spectrum disorder with and without intellectual disability (intelligence quotient <70) in children born extremely preterm.

STUDY DESIGN

This prospective multicenter (14 institutions in 5 states) birth cohort study included children born at 23-27 weeks' gestation in 2002 through 2004 who were evaluated for autism spectrum disorder and intellectual disability at age 10 years. Pregnancy information was obtained from medical records and by structured maternal interview. Cervical-vaginal "infection" refers to maternal report of bacterial infection (n = 4), bacterial vaginosis (n = 30), yeast infection (n = 62), mixed infection (n = 4), or other/unspecified infection (n = 43; eg, chlamydia, trichomonas, or herpes). We do not know the extent to which infection per se was confirmed by microbial colonization. We use the terms "fetal growth restriction" and "small for gestational age" interchangeably in light of the ongoing challenge to discern pathologically from constitutionally small newborns. Severe fetal growth restriction was defined as a birthweight Z-score for gestational age at delivery <-2 (ie, ≥2 SD below the median birthweight in a referent sample that excluded pregnancies delivered for preeclampsia or fetal indications). Participants were classified into 4 groups based on whether or not they met rigorous diagnostic criteria for autism spectrum disorder and intellectual disability (autism spectrum disorder+/intellectual disability-, autism spectrum disorder+/intellectual disability+, autism spectrum disorder-/intellectual disability+, and autism spectrum disorder-/intellectual disability-). Temporally ordered multinomial logistic regression models were used to examine the information conveyed by perinatal factors about increased risk for autism spectrum disorder and/or intellectual disability (autism spectrum disorder+/intellectual disability-, autism spectrum disorder+/intellectual disability+, and autism spectrum disorder-/intellectual disability+).

RESULTS

In all, 889 of 966 (92%) children recruited were assessed at age 10 years, of whom 857 (96%) were assessed for autism spectrum disorder; of these, 840 (98%) children were assessed for intellectual disability. Autism spectrum disorder+/intellectual disability- was diagnosed in 3.2% (27/840), autism spectrum disorder+/intellectual disability+ in 3.8% (32/840), and autism spectrum disorder-/intellectual disability+ in 8.5% (71/840). Maternal report of presumed cervical-vaginal infection during pregnancy was associated with increased risk of autism spectrum disorder+/intellectual disability+ (odds ratio, 2.7; 95% confidence interval, 1.2-6.4). The lowest gestational age category (23-24 weeks) was associated with increased risk of autism spectrum disorder+/intellectual disability+ (odds ratio, 2.9; 95% confidence interval, 1.3-6.6) and autism spectrum disorder+/intellectual disability- (odds ratio, 4.4; 95% confidence interval, 1.7-11). Severe fetal growth restriction was strongly associated with increased risk for autism spectrum disorder+/intellectual disability- (odds ratio, 9.9; 95% confidence interval, 3.3-30), whereas peripartum maternal fever was uniquely associated with increased risk of autism spectrum disorder-/intellectual disability+ (odds ratio, 2.9; 95% confidence interval, 1.2-6.7).

CONCLUSION

Our study confirms that low gestational age is associated with increased risk for autism spectrum disorder irrespective of intellectual ability, whereas severe fetal growth restriction is strongly associated with autism spectrum disorder without intellectual disability. Maternal report of cervical-vaginal infection is associated with increased risk of autism spectrum disorder with intellectual disability, and peripartum maternal fever is associated with increased risk for intellectual disability without autism spectrum disorder.