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Developmental outcome at 18 and 24 months of age in very preterm children: a cohort study from 1996 to 1997
Gerlinde M S J Stoelhorst1, Monique Rijken, Shirley E Martens
1Department of Pediatrics, Leiden University Medical Center, Neonatology, J6-S, PO Box 9600, Leiden 2300 RC, The Netherlands.
Insights
Forty percent of very premature infants experienced developmental delays by 18 and 24 months. Postnatal dexamethasone treatment significantly increased the risk of delayed psychomotor development in these children.
Area of Science:
- Neonatal development
- Pediatric neurology
- Developmental pediatrics
Background:
- Prematurity, defined as gestational age (GA) less than 32 weeks, poses significant risks for long-term developmental outcomes.
- Understanding the specific developmental trajectories and risk factors in very preterm infants is crucial for early intervention.
Purpose of the Study:
- To investigate the impact of prematurity (GA < 32 weeks) on mental and psychomotor development at corrected ages of 18 and 24 months.
- To identify predictors of developmental delay in a cohort of very preterm infants.
Main Methods:
- Prospective, regionally defined cohort study (Leiden Follow-Up Project on Prematurity) of infants born < 32 weeks GA.
- Developmental assessment using Bayley Scales of Infant Development I, measuring Mental Developmental Index (MDI) and Psychomotor Developmental Index (PDI).
- Analysis of factors including socioeconomic status, ethnicity, and postnatal treatments like dexamethasone.
Main Results:
- Moderate to severe mental and/or psychomotor developmental delay was observed in 40% of children at both 18 and 24 months.
- Postnatal dexamethasone treatment was associated with an increased risk of delayed development, with significantly lower PDI scores in treated infants.
- Other predictors of delay included bronchopulmonary dysplasia, ethnicity, maternal age, birthweight, and gender.
Conclusions:
- A substantial proportion (40%) of very preterm infants exhibit developmental delays by 18-24 months corrected age.
- Postnatal dexamethasone administration is a significant risk factor for delayed psychomotor development in this population.
- Early identification of risk factors and targeted interventions are essential for improving outcomes in very preterm infants.
Objective:
To determine the effect of prematurity (gestational age (GA) < 32 weeks) on developmental outcome at the corrected age of 18 and 24 months in a regionally defined, prospective cohort study.
Study Design:
The Leiden Follow-Up Project on Prematurity (LFUPP) includes all live-born infants < 32 weeks GA, born in 1996/1997 in three Dutch health regions (n=266). Mental and psychomotor developmental indices (MDI, PDI) were determined with the Bayley Scales of Infant Development I: > or = -1 S.D.: normal, -2 to -1 S.D.: moderate delay and < -2 S.D.: severe delay.
Results:
At 18 months 168 (71%) and at 24 months, 151 children (64%) of 235 survivors were assessed. Moderate to severely delayed mental and/or psychomotor development occurred in 40% of the children at both ages. Children lost to follow-up were of lower socioeconomic status and more frequently of non-Dutch origin. Since non-Dutch origin negatively affected the outcome at both test ages, availability of the data of these children would probably have worsened the outcome. Postnatal treatment with dexamethasone was associated with an increased risk of delayed development. Other independent predictors of delayed development were bronchopulmonary dysplasia at 18 months and ethnicity, maternal age at birth, birthweight and gender at 24 months. After adjustment for these other predictors of delayed development, the mean PDI of dexamethasone-treated infants was 16.1 points lower than of non-treated infants at 18 months (p=0.03) and 12.7 points lower at 24 months (p=0.04).
Conclusions:
At 18 and 24 months corrected age, 40% of the very prematurely born children had both delayed mental and/or psychomotor development. Treatment with dexamethasone postnatally was a major risk factor for delayed (psychomotor) development.
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