Related Experiment Video
Updated: Jul 18, 2026
Assessment and Evaluation of the High Risk Neonate: The NICU Network Neurobehavioral Scale
Published on: August 25, 2014
Neurodevelopmental outcome in extremely preterm infants at 2.5 years after active perinatal care in Sweden
Fredrik Serenius1, Karin Källén, Mats Blennow
1Department of Women's and Children's Health, Section for Pediatrics, Uppsala University, S-751 85 Uppsala, Sweden. fredrik.serenius@kbh.uu.se
Insights
Active perinatal care improves survival for extremely preterm infants, but neurodevelopmental outcomes at 2.5 years show increased rates of disability. Outcomes improved with each week of gestational age, offering crucial information for families.
Area of Science:
- Neonatal care and developmental pediatrics
- Perinatal medicine and infant neurodevelopment
- Public health and epidemiology of preterm birth
Background:
- Active perinatal care significantly increases survival rates for extremely preterm infants.
- However, enhanced survival may correlate with a higher incidence of neurodevelopmental disabilities among survivors.
- Understanding long-term neurodevelopmental outcomes is crucial for informed clinical practice and parental counseling.
Purpose of the Study:
- To assess the neurodevelopmental status of extremely preterm children at 2.5 years of corrected age.
- To compare the neurodevelopmental outcomes of extremely preterm survivors with those of term-born control infants.
- To identify factors influencing neurodevelopmental outcomes, such as gestational age at birth.
Main Methods:
- A population-based prospective cohort study included extremely preterm infants (born before 27 weeks gestation) in Sweden (2004-2007).
- Survivors were assessed at 2.5 years corrected age using the Bayley Scales of Infant and Toddler Development (3rd edition) for cognitive, language, and motor skills.
- Comparisons were made with matched singleton control infants born at term; cerebral palsy, visual, and hearing impairments were also assessed.
Main Results:
- Extremely preterm children exhibited significantly lower mean scores in cognition, language, and motor development compared to term-born controls.
- Higher rates of moderate to severe cognitive, language, and motor disabilities were observed in the preterm group.
- Cerebral palsy, blindness, and hearing impairments were also more prevalent in extremely preterm survivors; disability rates decreased with increasing gestational age.
Conclusions:
- A significant proportion (73%) of extremely preterm children receiving active perinatal care had mild or no disability at 2.5 years corrected age.
- Neurodevelopmental outcomes demonstrated a positive trend, improving with each additional week of gestational age at birth.
- These findings are vital for clinicians counseling families regarding the potential neurodevelopmental impact of extremely preterm birth.
Importance:
Active perinatal care increases survival of extremely preterm infants; however, improved survival might be associated with increased disability among survivors.
Objective:
To determine neurodevelopmental outcome in extremely preterm children at 2.5 years (corrected age).
Design, Setting, And Participants:
Population-based prospective cohort of consecutive extremely preterm infants born before 27 weeks of gestation in Sweden between 2004 and 2007. Of 707 live-born infants, 491 (69%) survived to 2.5 years. Survivors were assessed and compared with singleton control infants who were born at term and matched by sex, ethnicity, and municipality. Assessments ended in February 2010 and comparison estimates were adjusted for demographic differences.
Main Outcomes And Measures:
Cognitive, language, and motor development was assessed with Bayley Scales of Infant and Toddler Development (3rd edition; Bayley-lll), which are standardized to mean (SD) scores of 100 (15). Clinical examination and parental questionnaires were used for diagnosis of cerebral palsy and visual and hearing impairments. Assessments were made by week of gestational age.
Results:
At a median age of 30.5 months (corrected), 456 of 491 (94%) extremely preterm children were evaluated (41 by chart review only). For controls, 701 had information on health status and 366 had Bayley-lll assessments. Mean (SD) composite Bayley-III scores (cognition, 94 [12.3]; language, 98 [16.5]; motor, 94 [15.9]) were lower than the corresponding mean scores for controls (cognition, 104 [10.6]; P < .001; adjusted difference in mean scores, 9.2 [99% CI, 6.9-11.5]; language, 109 [12.3]; P < .001; adjusted difference in mean scores, 9.3 [99% Cl, 6.4-12.3]; and motor, 107 [13.7]; P < .001; adjusted difference in mean scores, 12.6 [99% Cl, 9.5-15.6]). Cognitive disability was moderate in 5% of the extremely preterm group vs 0.3% in controls (P < .001) and it was severe in 6.3% of the extremely preterm group vs 0.3% in controls (P < .001). Language disability was moderate in 9.4% of the extremely preterm group vs 2.5% in controls (P < .001) and severe in 6.6% of the extremely preterm group vs 0% in controls (P < .001). Other comparisons between the extremely preterm group vs controls were for cerebral palsy (7.0% vs 0.1%; P < .001), for blindness (0.9% vs 0%; P = .02), and for hearing impairment (moderate and severe, 0.9% vs 0%; P = .02, respectively). Overall, 42% (99% CI, 36%-48%) of extremely preterm children had no disability, 31% (99% CI, 25%-36%) had mild disability, 16% (99% CI, 12%-21%) had moderate disability, and 11% (99% CI, 7.2%-15%) had severe disability. Moderate or severe overall disability decreased with gestational age at birth (22 weeks, 60%; 23 weeks, 51%; 24 weeks, 34%; 25 weeks, 27%; and 26 weeks, 17%; P for trend < .001).
Conclusions And Relevance:
Of children born extremely preterm and receiving active perinatal care, 73% had mild or no disability and neurodevelopmental outcome improved with each week of gestational age. These results are relevant for clinicians counseling families facing extremely preterm birth.
