Long-term outcome at age 7-10 years after extreme prematurity - a prospective, two centre cohort study of children born before 25 completed weeks of gestation (1999-2003)

Neurodevelopmental disorders and somatic diagnoses in a national cohort of children born before 24 weeks of gestation

AIM

This study investigated childhood diagnoses in children born extremely preterm before 24 weeks of gestation.

METHODS

Diagnoses of neurodevelopmental disorders and selected somatic diagnoses were retrospectively retrieved from national Swedish registries for children born before 24 weeks from 2007 to 2018. Their individual medical files were also examined.

RESULTS

We studied 383 children born at a median of 23.3 (range 21.9-23.9) weeks, with a median birthweight of 565 (range 340-874) grams. Three-quarters (75%) had neurodevelopmental disorders, including speech disorders (52%), intellectual disabilities (40%), attention deficit hyperactivity disorder (30%), autism spectrum disorders (24%), visual impairment (22%), cerebral palsy (17%), epilepsy (10%) and hearing impairment (5%). More boys than girls born at 23 weeks had intellectual disabilities (45% vs. 27%, p < 0.01) and visual impairment (25% vs. 14%, p < 0.01). Just over half of the cohort (55%) received habilitation care. The majority (88%) had somatic diagnoses, including asthma (63%) and failure to thrive/short stature (39%).

CONCLUSION

Most children born before 24 weeks had neurodevelopmental disorders and/or additional somatic diagnoses in childhood and were referred to habilitation services. Clinicians should be aware of the multiple health and developmental problems affecting these children. Resources are needed to identify their long-term support needs at an early stage.

Identifying the Critical Threshold for Long-Term Pediatric Neurological Hospitalizations of the Offspring in Preterm Delivery

We opted to investigate whether a critical threshold exists for long-term pediatric neurological morbidity, and cerebral palsy (CP), in preterm delivery, via a population-based cohort analysis. Four study groups were classified according to their gestational age at birth: 24–27.6, 28–31.6, 32–36.6 weeks and term deliveries, evaluating the incidence of long-term hospitalizations of the offspring due to neurological morbidity. Cox proportional hazard models were performed to control for confounders. A Kaplan–Meier survival curve was used to compare the cumulative neurological morbidity incidence for each group. A total of 220,563 deliveries were included: 0.1% (118) occurred at 24–27.6 weeks of gestation, 0.4% (776) occurred at 28–31.6 weeks of gestation, 6% (13,308) occurred at 32–36.6 weeks of gestation and 93% (206,361) at term. In a Cox model, while adjusting for confounders, delivery before 25 weeks had a 3.9-fold risk for long-term neurological morbidity (adjusted HR (hazard ratio) = 3.9, 95% CI (confidence interval) 2.3–6.6; p < 0.001). The Kaplan–Meier survival curve demonstrated a linear association between long-term neurological morbidity and decreasing gestational age. In a second Cox model, adjusted for confounders, infants born before 25 weeks of gestation had increased rates of CP (adjusted HR = 62.495% CI 25.6–152.4; p < 0.001). In our population, the critical cut-off for long-term neurological complications is delivery before 25 weeks gestation.

Neurodevelopmental outcome descriptions in cohorts of extremely preterm children

BACKGROUND AND OBJECTIVES

Caregivers and clinicians of extremely preterm infants (born before 26 weeks' gestation) depend on long-term follow-up research to inform clinical decision-making. The completeness of outcome reporting in this area is unknown. The objective of this study was to evaluate the reporting of outcome definitions, selection, measurement and analysis in existing cohort studies that report on neurodevelopmental outcomes of children born extremely preterm.

METHODS

We evaluated the completeness of reporting of 'cognitive function' and 'cerebral palsy' in prospective cohort studies summarised in a meta-analysis that assessed the effect of preterm birth on school-age neurodevelopment. Outcome reporting was evaluated using a checklist of 55 items addressing outcome selection, definition, measurement, analysis, presentation and interpretation. Reporting frequencies were calculated to identify strengths and deficiencies in outcome descriptions.

RESULTS

All 14 included studies reported 'cognitive function' as an outcome; nine reported both 'cognitive function' and 'cerebral palsy' as outcomes. Studies reported between 26% and 46% of the 55 outcome reporting items assessed; results were similar for 'cognitive function' and 'cerebral palsy' (on average 34% and 33% of items reported, respectively). Key methodological concepts often omitted included the reporting of masking of outcome assessors, methods used to handle missing data and stakeholder involvement in outcome selection.

CONCLUSIONS

The reporting of neurodevelopmental outcomes in cohort studies of infants born extremely preterm is variable and often incomplete. This may affect stakeholders' interpretation of study results, impair knowledge synthesis efforts and limit evidence-based decision-making for this population.

Gestational Age, Health, and Educational Outcomes in Adolescents

BACKGROUND AND OBJECTIVES

As outcomes for extremely premature infants improve, up-to-date, large-scale studies are needed to provide accurate, contemporary information for clinicians, families, and policy makers. We used nationwide New Zealand data to explore the impact of gestational age on health and educational outcomes through to adolescence.

METHODS

We performed a retrospective cohort study of all births in New Zealand appearing in 2 independent national data sets at 23 weeks' gestation or more. We report on 2 separate cohorts: cohort 1, born January 1, 2005 to December 31, 2015 (613 521 individuals), used to study survival and midterm health and educational outcomes; and cohort 2, born January 1, 1998 to December 31, 2000, and surviving to age 15 years (146 169 individuals), used to study high school educational outcomes. Outcomes described by gestational age include survival, hospitalization rates, national well-being assessment outcomes at age 4 years, rates of special education support needs in primary school, and national high school examination results.

RESULTS

Ten-year survival increased with gestational age from 66% at 23 to 24 weeks to >99% at term. All outcomes measured were strongly related to gestational age. However, most extremely preterm children did not require special educational support and were able to sit for their national high school examinations.

CONCLUSIONS

Within a publicly funded health system, high-quality survival is achievable for most infants born at periviable gestations. Outcomes show improvement with gestational ages to term. Outcomes at early-term gestation are poorer than for children born at full term.

Long-Term Functioning and Participation Across the Life Course for Preterm Neonatal Intensive Care Unit Graduates

To understand the trajectories of risk and resilience in the vulnerable preterm and neonatal brain, clinicians must go beyond survival and critically examine on a population basis the functional outcomes of children, adolescents, and adults across their life course. Evaluations must go well beyond Bayley assessments and counts of neonatal morbidities, such as bronchopulmonary dysplasia, retinopathy of prematurity, sonographic brain injury, sepsis, and necrotizing enterocolitis. Proactively providing support to families and developmental and educational supports to children can optimize academic functioning and participation in adult learning, physical and behavioral health activities, community living, relationships, and employment.

Co-occurrence and Severity of Neurodevelopmental Burden (Cognitive Impairment, Cerebral Palsy, Autism Spectrum Disorder, and Epilepsy) at Age Ten Years in Children Born Extremely Preterm

BACKGROUND

This study aims to determine the prevalence of neurodevelopmental impairments at age ten years among children born extremely preterm (less than 28 weeks gestational age) and to offer a framework for categorizing neurological limitations.

METHODS

A multicenter, prospective cohort follow-up study recruited 889 ten-year-old children born from 2002 to 2004. We assessed prevalence of cognitive impairment, measured by intelligent quotient and tests of executive function, cerebral palsy (CP), autism spectrum disorder (ASD), and epilepsy singly and in combination. The three levels of impairment severity were: category I-no major neurodevelopmental impairment; category II-normal cognitive ability with CP, ASD, and/or epilepsy; and category III-children with cognitive impairment.

RESULTS

A total 214 of 873 children (25%) had cognitive impairment, 93 of 849 children (11%) had CP, 61 of 857 children (7%) had ASD, and 66 of 888 children (7%) had epilepsy. Further, 19% of all children had one diagnosis, 10% had two diagnoses, and 3% had three diagnoses. Decreasing gestational age was associated with increasing number of impairments (P < 0.001). Half the children with cognitive impairment and one third of children with CP, ASD, or epilepsy had a single impairment. Six hundred one (68% [95% CI, 64.5%-70.7%]) children were in category I, 74 (8% [95% CI, 6.6%-10.3%]) were in category II, and 214 (24% [95% CI 21.7%-27.4%]) were in category III.

CONCLUSIONS

Three quarters of children had normal intellect at age ten years; nearly 70% were free of neurodevelopmental impairment. Forty percent of children with impairments had multiple diagnoses.

Should the Gross Motor Function Classification System be used for children who do not have cerebral palsy?

This literature review addressed four questions. (1) In which populations other than cerebral palsy (CP) has the Gross Motor Function Classification System (GMFCS) been applied? (2) In what types of study, and why was it used? (3) How was it modified to facilitate these applications? (4) What justifications and evidence of psychometric adequacy were used to support its application? A search of PubMed, MEDLINE, and Embase databases (January 1997 to April 2017) using the terms: 'GMFCS' OR 'Gross Motor Function Classification System' yielded 2499 articles. 118 met inclusion criteria and reported children/adults with 133 health conditions/clinical descriptions other than CP. Three broad GMFCS applications were observed: as a categorization tool, independent variable, or outcome measure. While the GMFCS is widely used for children with health conditions/clinical description other than CP, researchers rarely provided adequate justification for these uses. We offer recommendations for development/validation of other condition-specific classification systems and discuss the potential need for a generic gross motor function classification system.

WHAT THIS PAPER ADDS

The Gross Motor Function Classification System should not be used outside cerebral palsy or as an outcome measure. The authors provide recommendations for development and validation of condition-specific or generic classification systems.

Factors affecting the cognitive profile of 11-year-old children born very preterm

BackgroundPreterm birth is a risk for cognitive development. This study assessed the cognitive profile of children born very preterm at the age of 11 years as well as the associated risk factors.MethodsA total of 128 children born very preterm were included. Magnetic resonance imaging was performed at term age. Cognitive development was assessed using the full-scale intelligence quotient (IQ) and four domains of the Wechsler Intelligence Scale for Children, fourth edition (WISC-IV), Finnish translation. The results were compared with test norms.ResultsMost study children performed at average (51%) or low average (21%) levels in the full-scale IQ assessment. The correlation between 5- and 11-year full-scale IQ was 0.73 (P<0.001). Compared with the normative data, children born very preterm performed poorer in all domains of the cognitive profile. The only significant risk factor for poor general cognition was major brain pathology. When considering all four domains of WISC-IV, low paternal education, male gender, and low birth weight z score were also found to be significant risk factors.ConclusionsLess than one-third of the children born very preterm performed below the low average cognitive level at 11 years of age. Specific neonatal and sociodemographic risk factors were identified as affecting the cognitive profile.

Intra-amniotic administration of lipopolysaccharide induces spontaneous preterm labor and birth in the absence of a body temperature change

OBJECTIVE

Intra-amniotic infection is associated with spontaneous preterm labor. In most cases, the infection is subclinical and bacteria are detected in the amniotic cavity rather than in the chorioamniotic membranes. The aims of this study were to establish a model of intra-amniotic lipopolysaccharide (LPS)-induced preterm labor/birth that resembles the subclinical syndrome and to compare this model to two established models of LPS-induced preterm labor/birth.

METHODS

Pregnant B6 mice received an intra-amniotic, intra-uterine, or intra-peritoneal injection of LPS (100 ng/amniotic sac, 15 μg/25 μL, and 15 μg/200 μL respectively) or PBS (control). Following injection, body temperature (every two hours for a 12-h period), gestational age, and the rate of preterm labor/birth were recorded.

RESULTS

An intra-amniotic injection of LPS resulted in preterm labor/birth [LPS 80 ± 24.79% (8/10) versus PBS 0% (0/8); p = 0.001] without causing maternal hypothermia. Intra-peritoneal [LPS 100% (8/8) versus PBS 0% (0/8); p < 0.001)] and intra-uterine [LPS 100% (8/8) versus PBS 28.57 ± 33.47% (2/7); p =0 .007] injections of LPS induced preterm labor/birth; yet, maternal hypothermia was observed.

CONCLUSION

Intra-amniotic injection of LPS induces preterm labor/birth in the absence of a body temperature change, which resembles the subclinical syndrome.

An elevated amniotic fluid prostaglandin F2α concentration is associated with intra-amniotic inflammation/infection, and clinical and histologic chorioamnionitis, as well as impending preterm delivery in patients with preterm labor and intact membranes

OBJECTIVE

To determine whether an elevated amniotic fluid concentration of prostaglandin F2α (PGF2α) is associated with intra-amniotic inflammation/infection and adverse pregnancy outcomes in patients with preterm labor and intact membranes.

MATERIALS AND METHODS

The retrospective cohort study included 132 patients who had singleton pregnancies with preterm labor (< 35 weeks of gestation) and intact membranes. Amniotic fluid was cultured for aerobic and anaerobic bacteria as well as for genital mycoplasmas. Intra-amniotic inflammation was defined by an elevated amniotic fluid matrix metalloproteinase-8 (MMP-8) concentration (>23 ng/mL). PGF2α was measured with a sensitive and specific immunoassay. The amniotic fluid PGF2α concentration was considered elevated when it was above the 95th percentile among pregnant women at 15-36 weeks of gestation who were not in labor (≥170 pg/mL).

RESULTS

(1) The prevalence of an elevated amniotic fluid PGF2α concentration was 40.2% (53/132) in patients with preterm labor and intact membranes; (2) patients with an elevated amniotic fluid PGF2α concentration had a significantly higher rate of positive amniotic fluid culture [19% (10/53) versus 5% (4/79); p = 0.019], intra-amniotic inflammation/infection [49% (26/53) versus 20% (16/79); p = 0.001], spontaneous preterm delivery, clinical and histologic chorioamnionitis, and funisitis, as well as a higher median amniotic fluid MMP-8 concentration and amniotic fluid white blood cell count and a shorter amniocentesis-to-delivery interval than those without an elevated concentration of amniotic fluid PGF2α (p < 0.05 for each); and (3) an elevated amniotic fluid PGF2α concentration was associated with a shorter amniocentesis-to-delivery interval after adjustment for the presence of intra-amniotic inflammation/infection [hazard ratio 2.1, 95% confidence interval (CI) 1.4-3.1; p = 0.001].

CONCLUSION

The concentration of PGF2α was elevated in the amniotic fluid of 40.2% of patients with preterm labor and intact membranes and is an independent risk factor for intra-amniotic inflammation/infection, impending preterm delivery, chorioamnionitis, and funisitis.

A new antibiotic regimen treats and prevents intra-amniotic inflammation/infection in patients with preterm PROM

OBJECTIVES

To determine whether a new antibiotic regimen could reduce the frequency of intra-amniotic inflammation/infection in patients with preterm PROM.

STUDY DESIGN

This retrospective cohort study was conducted to evaluate the effect of antibiotics on the frequency of intra-amniotic inflammation/infection based on the results of follow-up transabdominal amniocenteses from 89 patients diagnosed with preterm PROM who underwent serial amniocenteses. From 1993-2003, ampicillin and/or cephalosporins or a combination was used ("regimen 1"). A new regimen (ceftriaxone, clarithromycin and metronidazole) was used from 2003-2012 ("regimen 2"). Amniotic fluid was cultured and matrix metalloproteinase-8 (MMP-8) concentrations were measured.

RESULTS

(1) The rates of intra-amniotic inflammation and intra-amniotic inflammation/infection in patients who received regimen 2 decreased during treatment from 68.8% to 52.1% and from 75% to 54.2%, respectively. In contrast, in patients who received regimen 1, the frequency of intra-amniotic inflammation and infection/inflammation increased during treatment (31.7% to 55% and 34.1% to 58.5%, respectively); and (2) intra-amniotic inflammation/infection was eradicated in 33.3% of patients who received regimen 2, but in none who received regimen 1.

CONCLUSION

The administration of ceftriaxone, clarithromycin and metronidazole was associated with a more successful eradication of intra-amniotic inflammation/infection and prevented secondary intra-amniotic inflammation/infection more frequently than an antibiotic regimen which included ampicillin and/or cephalosporins in patients with preterm PROM.

A point of care test for the determination of amniotic fluid interleukin-6 and the chemokine CXCL-10/IP-10

OBJECTIVE

Intra-amniotic inflammation is a mechanism of disease implicated in preterm labor, preterm prelabor rupture of membrane, cervical insufficiency, a short cervix, and idiopathic vaginal bleeding. Determination of interleukin (IL)-6 with immunoassays has been proven for more than two decades to be an excellent method for the detection of intra-amniotic inflammation. However, assessment of IL-6 for this indication has been based on immunoassays which are not clinically available, and this has been an obstacle for the implementation of this test in clinical practice. It is now possible to obtain results within 20 min with a point of care (POC) test which requires minimal laboratory support. This test is based on lateral flow-based immunoassay. The objective of this study was to compare amniotic fluid (AF) IL-6 and interferon-γ - inducible protein 10 (IP-10 or CXCL-10) concentrations determined using lateral flow-based immunoassay or POC test and standard enzyme-linked immunosorbent assay (ELISA) techniques.

MATERIAL AND METHODS

AF samples were collected from patients with singleton gestations and symptoms of preterm labor (n = 20). AF IL-6 and IP-10 concentrations were determined by lateral flow-based immunoassay and ELISA. Intra-amniotic inflammation was defined as AF IL-6 ≥ 2.6 ng/ml. AF IL-6 and IP-10 concentrations between two assays were compared.

RESULTS

(1) Lateral flow-based immunoassay POC AF IL-6 and IP-10 test results were strongly correlated with concentrations of this cytokine/chemokine determined by ELISA (Spearman's ρ = 0.92 and 0.83, respectively, both p < 0.0001); (2) AF IL-6 concentrations determined by the lateral flow-based immunoassay test were, on average, 30% lower than those determined by ELISA, and the median difference was statistically significant (p < 0.0001); and (3) in contrast, AF IP-10 concentrations determined by the lateral flow-based immunoassay test were, on average, only 7% lower than those determined by ELISA, and the median difference was not statistically significant (p = 0.81).

CONCLUSION

AF IL-6 and IP-10 concentrations determined using a lateral flow-based immunoassay POC are strongly correlated with concentrations determined by conventional ELISA. This justifies further studies about the diagnostic indices and predictive values of this POC test.

Tract-Based Spatial Statistics in Preterm-Born Neonates Predicts Cognitive and Motor Outcomes at 18 Months

BACKGROUND AND PURPOSE

Adverse neurodevelopmental outcome is common in children born preterm. Early sensitive predictors of neurodevelopmental outcome such as MR imaging are needed. Tract-based spatial statistics, a diffusion MR imaging analysis method, performed at term-equivalent age (40 weeks) is a promising predictor of neurodevelopmental outcomes in children born very preterm. We sought to determine the association of tract-based spatial statistics findings before term-equivalent age with neurodevelopmental outcome at 18-months corrected age.

MATERIALS AND METHODS

Of 180 neonates (born at 24-32-weeks' gestation) enrolled, 153 had DTI acquired early at 32 weeks' postmenstrual age and 105 had DTI acquired later at 39.6 weeks' postmenstrual age. Voxelwise statistics were calculated by performing tract-based spatial statistics on DTI that was aligned to age-appropriate templates. At 18-month corrected age, 166 neonates underwent neurodevelopmental assessment by using the Bayley Scales of Infant Development, 3rd ed, and the Peabody Developmental Motor Scales, 2nd ed.

RESULTS

Tract-based spatial statistics analysis applied to early-acquired scans (postmenstrual age of 30-33 weeks) indicated a limited significant positive association between motor skills and axial diffusivity and radial diffusivity values in the corpus callosum, internal and external/extreme capsules, and midbrain (P < .05, corrected). In contrast, for term scans (postmenstrual age of 37-41 weeks), tract-based spatial statistics analysis showed a significant relationship between both motor and cognitive scores with fractional anisotropy in the corpus callosum and corticospinal tracts (P < .05, corrected). Tract-based spatial statistics in a limited subset of neonates (n = 22) scanned at <30 weeks did not significantly predict neurodevelopmental outcomes.

CONCLUSIONS

The strength of the association between fractional anisotropy values and neurodevelopmental outcome scores increased from early-to-late-acquired scans in preterm-born neonates, consistent with brain dysmaturation in this population.

Schul- und Verhaltensauffälligkeiten nach extremer Frühgeburtlichkeit im Alter von 7 bis 10 Jahren

Aufgrund verbesserter medizinischer Versorgung überleben heute immer mehr extrem Frühgeborene und haben Chancen auf ein Leben ohne Behinderung. Allerdings darf das Risiko langfristiger Entwicklungsstörungen nicht unterschätzt werden. In dieser Studie wurden 79 von 105 Kinder (75 %), die zwischen 1999 und 2003 vor vollendeter 25. Schwangerschaftswoche in zwei Perinatalzentren geboren wurden, im Alter von 7 bis 10 Jahren standardisiert nachuntersucht hinsichtlich neurologischer, körperlicher, kognitiver Fähigkeiten, schulischer Leistungen, Verhalten und Förderbedarf. Im Mittel lag der Gesamt-IQ bei 87, bei 38 % unter 85. Knapp die Hälfte der Kinder besuchte keine Regelschule. Neben Entwicklungsverzögerungen (64 %) traten gehäuft Entwicklungsstörungen schulischer Fertigkeiten (30 %), Aufmerksamkeitsdefizit-/Hyperaktivitätsstörungen (17 %) und Autismus-Spektrum-Erkrankungen (6 %) auf. Es bestand erhöhter medizinischer Therapie- sowie schulischer Förderbedarf. Bei extrem Frühgeborenen sind kognitive Einschränkungen, Verhaltensauffälligkeiten und Probleme der schulischen Adaptation häufig und erfordern langfristig Therapien und Fördermaßnahmen.