Functional dissection of prenatal drug effects on baby brain and behavioral development.

Prenatal drug exposure (PDE) is known to affect fetal brain development with documented long-term consequences. Most studies of PDE effects on the brain are based on animal models. In this study, based on a large sample of 133 human neonates and leveraging a novel linear mixed-effect model designed for intersubject variability analyses, we studied the effects of six prenatally exposed drugs (i.e., nicotine, alcohol, selective serotonin reuptake inhibitor, marijuana, cocaine, and opioids) on neonatal whole-brain functional organization and compared them with five other critical nondrug variables (i.e., gestational age at birth/scan, sex, birth weight, and maternal depression). The behavioral implications were also examined. Magnitude-wise, through summing across individual drug effects, our results highlighted ~5% of whole-brain functional connections (FCs) affected by PDE, which was highly comparable with the combined effects of the five nond rug variables. Spatially, the detected PDE effects featured drug-specific patterns with a common bias in higher-order brain regions/networks. Regarding brain-behavioral relationships, the detected connections showing significant drug effects also demonstrated significant correlations with 3-month behavioral outcomes. Further mediation analyses supported a mediation role of the detected brain FCs between PDE status and cognitive/language outcomes. Our findings of widespread, and spatially biased PDE effect patterns coupled with significant behavioral implications may hopefully stimulate more human-based studies into effects of PDE on long-term developmental outcomes.