# Two-Year Longitudinal Motor Performance of Very Preterm and/or Very-Low-Birth-Weight Infants in Suriname

## TL;DR

This study tracks motor development in preterm infants in Suriname over two years, finding that motor delays emerge by 12 months and are influenced by birth weight, not an early intervention program.

## Contribution

The study provides longitudinal motor performance data for very preterm infants in a middle-income country and evaluates the impact of an early motor intervention program.

## Key findings

- Motor scores declined between 3 and 12 months but stabilized by 24 months, with scores significantly below reference values.
- Lower birth weight z-scores were associated with lower initial motor scores and less decline over time.
- The early motor intervention program did not significantly affect motor performance after adjusting for intervention frequency.

## Abstract

Background/Objectives: Follow-up studies in very preterm infants are common, but fewer studies are situated in low- or middle-income countries. In a prospective cohort study, we explored longitudinal motor performance trajectories and influencing factors, including an early motor intervention program. Very preterm infants (gestational age < 32 weeks and/or very-low-birth-weight < 1500 g) in the middle-income country of Suriname were included. Methods: We assessed 149 (49.7% boys) infants (mean gestational age 29+6, mean birth weight 1271 g) at 3, 12, and 24 months with the Bayley Scales of Infant and Toddler Development for fine motor (FM), gross motor (GM), and composite scores (CSs). Influencing perinatal and environmental factors were explored. Delayed-scoring infants were referred to a motor intervention program. Data were analyzed using mixed-model linear regression. Results: The Bayley mean FM and GM scores decreased between 3 and 12 months and stabilized at 24 months. The mean CS at 3, 12, and 24 months was 102.3, 92.7, and 92.2, respectively. The latter two were significantly below the reference values (100, SD 15, p < 0.01). Birth weight z-scores significantly influenced FM (p = 0.013) and CS (p = 0.009); a lower birth weight was associated with initially lower scores and a smaller decline over time than a higher birth weight. The motor intervention program (n = 54) showed no significant interaction effects at all time points after correction for frequency of interventions (no; 1–5; >5 interventions). Conclusions: Motor performance was normal at 3 months and delayed at 12 and 24 months. Birth weight, but not the early intervention program, influenced longitudinal motor trajectories. We recommend follow-up of motor performance and suggest adding the Prechtl General Movement assessment at 3 months of age. The clinical implementation of the early motor invention program needs additional studies to reach an adequate training level.