RESUMEN
Objective: To investigate the effects of enriched environments on behavioral development at toddler period of preterm who had experienced early repeated operative pain. Methods: A cross-sectional study was conducted. A total of 80 high-risk preterm children of 2 years of age, who had experienced repeated pain stimuli in the neonatal intensive care unit (NICU), were enrolled as preterm group from the High-risk Children Clinic of Children's Hospital of Nanjing Medical University from October 2016 to March 2021. Furthermore, 39 full-term healthy children, aged 2 years, who were undergoing routine check-ups during the same period, were selected as the full-term group. The preterm group was further divided into preterm intervention group and preterm non-intervention group based on the implementation of enriched environment interventions. Data of neonatal characteristics from 3 groups were collected. Growth and development indicators at the age of 2 years were measured. Neuropsychological development evaluated by Gesell developmental scale. Behavioral development evaluated by child behavior check list. The salivary cortisol levels in response to novelty (baseline, task, end) were collected. The family environment, including maternal parenting pressure, were evaluated through a survey questionnaire. One-way ANOVA and least significant difference (LSD) tests were used to compare physical development, maternal parenting stress, Gesell neuropsychological development, and behavioral problems among the 3 groups. A repeated-ANOVA and LSD tests were employed to compare the patterns of salivary cortisol secretion. Pearson correlation analysis was used to explore the influencing factors related to neuropsychological and behavioral development and cortisol level. Results: There were 44 cases in the preterm intervention group (17 males, gestational age of (31.3±2.8) weeks), and 36 in the preterm non-intervention group (29 males, gestational age of (32.5±2.6) weeks). The full-term group consisted of 39 children (23 males, gestational age of (39.3±2.1) weeks). At 2 years of age, the height, weight, and head circumference of the preterm intervention group and non-intervention group were all lower than those of the full-term group (all P<0.05).The Gesell developmental schedule showed that the preterm non-intervention group scored all lower in gross motor, fine motor, adaptive, language and personal-social domains compared to the full-term group (91±7 vs. 97±6, 88±9 vs. 94±6, 89±8 vs. 99±8, 84±10 vs. 100±15, 89±7 vs. 95±6), with statistical significance (all P<0.01). The preterm intervention group scored all higher than the preterm non-intervention group in gross motor, fine motor, adaptive and language domains (all P<0.05), with no significant difference compared to the full-term group (all P>0.05). The number of needle painful procedures during hospitalization in NICU of the non-intervention group was negatively correlated to the adaptive development quotient (r=-0.48, P<0.05). Furthermore, the preterm non-intervention group exhibited higher scores in social withdrawal, depression, somatic complaints, aggression, and destructive behaviors compare to the full-term group and preterm intervention group (F=8.07, 5.67, 7.72, 7.90, 7.06; all P<0.05); while the preterm intervention group showed no significant difference compared to full-term group (all P>0.05). Behavioral problems (social withdrawal and depression) in the preterm non-intervention group were positively correlated with maternal parenting stress (r=0.66, 0.50; both P<0.05). In response to novel visual stimuli and cognitive challenges, the preterm non-intervention group had significantly higher salivary cortisol levels compared to the full-term group (P=0.006), which were negatively correlated with the frequency of early painful procedures (r=-0.83, -0.80; both P<0.01). There was no significant difference in cortisol secretion pattern between the intervention group and the full-term group (P=0.772). Conclusion: Enriched environmental interventions can improve neuropsychological development, decrease behavioral problems, and down-regulate consistent high cortisol response to task in preterm infants who have experienced repeated procedural pain in the NICU by the age of 2 years.
