Assisted reproductive technology and neurodevelopment in children at 1 year of age: a longitudinal birth cohort study.

Background: With remarkable advancements in assisted reproductive technology (ART), the number of ART-conceived children continues to increase. Despite increased research investigating the outcomes of ART children, evidence on neurodevelopment remains controversial.

Objective: The aim of this study was to investigate the association between ART use and neurodevelopment in children at 1 year of age and to determine whether the characteristics of parental infertility and specific ART procedures affect neurodevelopment in children.

Study Design: The Jiangsu Birth Cohort enrolled couples who received ART treatment and who conceived spontaneously (2014-2020) in Jiangsu Province, China. In this study, we included 3531 pregnancies with 3840 cohort children who completed neurodevelopment assessment at 1 year of age, including 1906 infants conceived by ART (including 621 twins). Poisson regressions were fitted to estimate unadjusted and adjusted risk ratios (RRs) and 95% confidence intervals (CIs) for ART use with neurodevelopmental outcomes (cognition, receptive communication, expressive communication, fine motor, and gross motor) in children.

Results: Among singletons, ART use was associated with a 24% to 34% decrease in the risk for noncompetent development in 3 domains (cognition, adjusted RR, 0.66; 95% CI, 0.53-0.82; receptive communication, 0.76; 0.64-0.91; expressive communication, 0.69; 0.51-0.93) after adjustment for conventional covariates. However, an inverse association was observed in the gross motor domain, with ART singletons having a greater risk of being noncompetent in gross motor development than their non-ART counterparts (adjusted RR, 1.41; 95% CI, 1.11-1.79). Compared with singletons, twins resulting from ART treatment demonstrated compromised neurodevelopment in several domains. Furthermore, we continued to observe that the transfer of 'poor' quality embryos was associated with greater risks for noncompetent development in receptive communication (adjusted RR, 1.50; 95% CI, 1.05-2.14) and gross motor domains (1.55; 1.02-2.36) among ART singletons.

Conclusion: These results generally provide reassuring evidence among singletons born after ART in the cognition, communication, and fine motor domains, but drawn attention to their gross motor development. The quality of transferred embryos in ART treatment might be associated with offspring neurodevelopment; however, the potential associations warrant further validation in independent studies, and the clinical significance needs careful interpretation.