Stability of developmental status and risk of impairment at 24 and 36 months in late preterm infants.

Background: Few studies investigated whether late preterm infants might have developmental delays in several domains in early life and how stable the lag in developmental status might be.

Aim: We aimed to examine the stability of potential delays across developmental domains at 24 and 36 months of age in late preterm (34°-36 weeks) and term (≥37 weeks) children and whether the risk of delays remained high at 36 months.

Study Design, Subjects, And Outcome Measure: We conducted a prospective cohort analysis of the children of pregnant women participating in the Vitamin Antenatal Asthma Reduction Trial (VDAART). 652 children who were prospectively followed up and had parent-completed Ages Stages Questionnaires (ASQ-3) questionnaires at both 24 and 36 months were analyzed to assess their domain-specific developmental status.

Results: 6.61 % (42/635) of children had a late preterm birth. Developmental delays were stable between 24 and 36 months on all 5 domains for the children born preterm and on 4/5 domains for those born at term. The developmental domains with the status stability at 24 and 36 months in both late preterm and term children were the gross motor, communication, personal-social skills, and problem-solving. Late preterm children compared with term children remained at higher risk of delays at 36 months for gross motor, communication, and problem-solving skills (aOR = 4.54, 95 %CI: 1.81-10.79; aOR = 8.60, 95 %CI: 3.10-23.28 and aOR = 3.80, 95 %CI: 1.58-8.73, respectively).

Conclusion: Late preterm birth is associated with suboptimal development and stability in several domains at both 24 and 36 months and compared with term birth, requiring early monitoring and assessment of the developmental lag to avoid potential long-term implications.