71. Maternal Pregnancy Diet Quality Is Directly Associated with Autonomic Nervous System Function in 6-Month-Old Offspring (lay summary)

Krzeczkowski JE, Boylan K, Arbuckle TE, Muckle G, Poliakova N, Séguin JR,  Favotto LA, Savoy C, Amani B, Mortaji N, Van Lieshout  RJ. Journal of Nutrition. 2019 Oct 1. pii: nxz228. doi: 10.1093/jn/nxz228

Approximately half of all adults consume diets of less than ideal quality (low in nutrients and high in fats and sugars).  During pregnancy, the fetus’s organ systems are rapidly developing.  Fetal exposure to poor prenatal diet has the potential to alter the development of these systems, which may increase the child’s susceptibility to disease.  The autonomic nervous system is involved in many critically important processes in the body, including rate of breathing, heart rate and digestion. It also coordinates the body’s response to external and internal demands. As result, adverse development of this system may increase susceptibility to diseases. One way to assess autonomic nervous system function is by measuring the time between heart beats, and examining how much variability there is between these beats over a monitored time period– this is called heart rate variability.  Greater heart rate variability suggests a more flexible autonomic nervous system that is capable of adapting to a range of challenges.  In contrast, low heart rate variability suggests a more rigid system with limited capacity to respond to stressors.

The aim of this study was to examine associations between prenatal diet quality and heart rate variability in 400 mother-infant pairs from the MIREC-ID Study.  Maternal diet quality during pregnancy was estimated by questionnaire.  Infant heart rate variability was measured by electrocardiogram (ECG) in 6-month old infants.

This study found that 75% of the women consumed diets of average quality.  Poorer diet quality during pregnancy was associated with lower heart rate variability in infants, suggesting less flexibility of the autonomic nervous system to respond to stressors.  This may be a mechanism by which poor prenatal diet increases the child’s susceptibility to diseases later in life.

These findings suggest that consuming a healthy diet in pregnancy could play a role in lowering disease susceptibility in offspring. Therefore, these results could inform the development of interventions designed to improve health of both women and their infants.

This study was led by a PhD student at McMaster University.