Citation

Leung, Michael; Krishna, Aditi; Yang, Seungmi; Bassani, Diego G.; & Roth, Daniel E. (2020). Linear growth and mid-childhood cognitive outcomes in three birth cohorts of term-born children: an approach to integrating three growth models to explore critical windows. BMJ Open, 10(8), e036850. PMCID: PMC7451285

Abstract

OBJECTIVE: To illustrate that a mediation framework can help integrate inferences from three growth models to enable a comprehensive view of the associations between growth during specific developmental windows and mid-childhood IQ. DESIGN: We analysed direct and indirect associations between mid-childhood IQ and length/height growth in five early-life age intervals bounded by conception, birth, early, mid and late infancy, and mid-childhood using estimates from three growth models (lifecourse, conditional change and change score) applied to three historical birth cohorts. PARTICIPANTS AND SETTING: 12 088 term-born children from the Collaborative Perinatal Project (CPP) in the USA (n=2170), the Promotion of Breastfeeding Intervention Trial (PROBIT) in Belarus (n=8275) and the Cebu Longitudinal Health and Nutrition Survey (CLHNS) in the Philippines (n=1643). PRIMARY OUTCOME MEASURE: Mid-childhood IQ. RESULTS: Our analyses revealed cross-cohort and cross-interval variations in the direct and indirect effects of foetal and early childhood physical growth on mid-childhood IQ. For example, in CPP, there was a direct association of prenatal growth with IQ that was not evident in the other cohorts, whereas in PROBIT and CLHNS, we observed that foetal and early growth-IQ associations were mediated through size in later periods. CONCLUSION: Lifecourse, conditional change and change score growth models yield complementary inferences when appropriately interpreted. Future longitudinal studies of associations of early-life growth with later outcomes would benefit from adopting a causal mediation framework to integrate inferences from multiple complementary growth models.

Reference Type

Journal Article

Year Published

2020

Journal Title

BMJ Open

Author(s)

Leung, Michael
Krishna, Aditi
Yang, Seungmi
Bassani, Diego G.
Roth, Daniel E.

PMCID

PMC7451285