High threshold of total developmental quotient at 3 years for follow-up in extremely preterm infants

Aim: To investigate the relationship between the developmental quotient (DQ) at age 3 years and the need for educational support at school age in extremely preterm infants. Methods: A total of 176 infants with a gestational age of <28 weeks were analyzed. The total DQ and subscales were evaluated using the Kyoto Scale of Psychological Development (KSPD) test. Neurodevelopment at age 3 years was stratified using total DQ in a conventional (DQ < 70 as developmental delay, DQ 70- <85 as subnormal, DQ >= 85 as normal) and a modified way (subdividing normal into DQ 85- <93 as low-normal and DQ >= 93 as high-normal). The prevalence of future educational support was compared for each stratum. Additionally, subscales were compared between those with and without educational support in each total DQ stratum. Results: In conventional stratification, the prevalence of educational support was 32 (63 %) for developmental delay, 14 (24 %) for subnormal, and 10 (15 %) for normal. In modified stratification, the prevalence was 8 (26 %) for low-normal and 2 (5 %) for high-normal. While there was no significant difference in the odds of educational support between the normal and subnormal, the low-normal had significantly higher odds compared to the high-normal (OR 6.00; 95 % CI, 1.16-30.95, p = 0.03). Among the low-normal stratum, the language-social subscale was significantly lower in those with educational support. Conclusion: Setting high thresholds for total DQ and evaluating detailed subscales at age 3 years may be useful for developmental follow-up in extremely preterm infants.