Etiological subgroups of term small-for-gestational-age and childhood health outcomes

Abstract

Background: Small-for-gestational-age (SGA) has a heterogeneous etiology. Our study aimed to examine the childhood health outcomes of etiology-distinct term SGA subgroups.

Methods: Data from the Collaborative Perinatal Project were used. The etiological factors of SGA were categorized into five groups: maternal, fetal, placental, environmental and physiological factors. Primary child outcomes included low IQ and growth restriction. A total of 8417 term infants were eligible.

Results: Compared with AGA, SGA children due to fetal factors had the highest risk of low IQ (aOR = 1.94, 95% CI: 1.45-2.59). SGA infants due to physiological factors had the highest risk of growth restriction (aOR = 6.04, 95% CI: 3.93-9.27). SGA children had a higher risk of growth restriction with the aOR ranging from 3.05 (95% CI: 2.36-3.96) to 5.77 (95% CI: 4.29-7.75) for the number of risk factors that the SGA infants had from 1 to 5. SGA children with any risk factor were associated with a higher risk of lower IQ with the aOR ranging from 1.59 (95% CI: 1.31-1.94) to 1.96 (95% CI: 1.50-2.55). SGA without the five types of etiologies was not associated with adverse child outcomes except for growth restriction (aOR = 3.82, 95% CI: 2.62-5.55).

Conclusion: Term SGA of different etiologies may lead to different child health outcomes.

Impact: Our study found that SGA of different etiologies may lead to different child health outcomes. Compared with AGA, SGA children due to fetal factors had the highest risk of low IQ. SGA infants due to physiological factors had the highest risk of growth restriction. SGA babies should not be treated the same. In the era of precision medicine, our findings may help pediatricians and parents better manage SGA babies according to different etiologies and the number of risk factors.