Small for gestational age-cognitive performance from infancy to adulthood: an observational study

Area of Science:

• Developmental psychology
• Pediatric neurology
• Public health

Background:

• Small for gestational age (SGA) is a significant concern in perinatal health.
• Cognitive development trajectories in SGA individuals require further elucidation.
• The influence of confounding factors like very preterm/very low birthweight (VP/VLBW), socioeconomic status (SES), and parent-infant relationship on SGA outcomes is not fully understood.

Purpose of the Study:

• To investigate the long-term effects of being born small for gestational age (SGA) on cognitive performance from infancy to adulthood.
• To determine if the choice of SGA reference standard impacts these findings.
• To assess the independent contributions of SGA, VP/VLBW, SES, and parent-infant relationship to cognitive outcomes.

Main Methods:

• Longitudinal study of 414 participants from the Bavarian Longitudinal Study.
• SGA classification using neonatal or fetal growth references.
• Cognitive performance assessed via developmental quotient (DQ) and intelligence quotient (IQ) tests at multiple time points from infancy to 26 years of age.

Main Results:

• SGA was consistently associated with an 8-point lower IQ compared to appropriate for gestational age peers, irrespective of the reference standard used.
• This IQ deficit associated with SGA showed minimal narrowing into adulthood.
• Very preterm/very low birthweight (VP/VLBW), low socioeconomic status (SES), and a poor parent-infant relationship were also independently associated with significantly lower IQ scores.

Conclusions:

• Small for gestational age (SGA) is linked to enduring lower cognitive performance throughout development.
• The cognitive impact of SGA is independent of VP/VLBW, SES, and parent-infant relationship quality.
• Social factors exert an influence on IQ comparable to SGA, highlighting their importance in intervention strategies.