A-44 Implications of the Heart Rate Variability Power Spectrum on the Relationship between Prenatal Anxiety Exposure and Child Anxiety in 5-Year-Olds

Abstract

Objective To assess the role of the heart rate variability (HRV) in the relationship between prenatal anxiety exposure and subsequent child anxiety levels. Methods A longitudinal study of mother–child dyads (subsample of 89) measured maternal anxiety during the second trimester of pregnancy (self-reported via STAI-S) and subsequent child anxiety (maternal-reported via BASC-3) and baseline autonomic physiological measures (high and low frequency band of HRV power spectrum) at 5-years-old. Mediation analysis was conducted to test whether child high and/or low frequency HRV mediates the relationship between prenatal anxiety and child anxiety. Results Prenatal anxiety predicted child anxiety (β = 0.137, p = 0.004) and high frequency HRV (β = −0.009, p < 0.001), but not low frequency HRV (β = −0.002, p = 0.231). Mediation analysis using bootstrapping procedure revealed that high frequency HRV (β = 0.044, 95% CI [0.007, 0.085]), but not low frequency HRV (β = 0.0117, 95% CI [−0.007, 0.047]), mediated the relationship between prenatal anxiety and child anxiety. After controlling for high frequency HRV, prenatal anxiety was no longer associated with child anxiety (β = 0.0753, p = 0.148). Conclusion Results indicate that in-utero exposure to maternal anxiety influences the child’s high frequency but not low frequency HRV. Importantly, changes in only high frequency HRV from prenatal anxiety is driving the relationship between prenatal anxiety and child anxiety levels, indicating that maternal anxiety during pregnancy affects the development of the autonomic nervous system with long term effects on child emotional regulation. The results suggest that the high frequency portion of the HRV power spectrum should be assessed in a multidimensional model of fetal programming and subsequent mental health risk of the child.