Background: As a continuation of two large-scale, multicentre studies on the development of 5-year-old ICSI children, we present results of the follow-up study undertaken on the cognitive and motor development of 8-year-old ICSI children.
Methods: Developmental outcomes of 151 8-year-old singletons born through ICSI after 32 weeks of gestation were compared with those of 153 singletons of the same age born after spontaneous conception (SC). Part of this population was seen in a cohort at the age 5 years. Outcome measures include Wechsler Intelligence Scale for Children-Revised (WISC-R) and Movement Assessment Battery for Children (ABC).
Results: Regarding intellectual functioning, ICSI children tend to obtain significantly higher total (P < 0.01), verbal (P < 0.01) and performance (P < 0.05) intelligence scores than SC children, nevertheless remaining in similar ranges. These effects are small (Cohen's d < 0.50). High maternal educational level stayed in the regression as a factor accounting for some of the variance in total IQ between the groups. In terms of motor development, no significant differences were found between ICSI and SC children regarding overall motor skills, manual, balance and ball skills.
Conclusion: In this follow-up study, ICSI and SC children show a comparable cognitive and motor development until the age of 8 years.