Exposure to prenatal stressors and infant autonomic nervous system regulation of stress

Abstract

Objectives

The purpose of this study was to determine the relationship between fetal exposure to maternal prenatal stressors and infant parasympathetic (PNS) and sympathetic (SNS) nervous function at 3 timepoints across the first year of life.

Background

Autonomic nervous system impairments may mediate associations between gestational exposure to stressors and later infant health problems. Heart rate variability (HRV) provides a sensitive index of PNS and SNS function. However, no studies have assessed longitudinal associations between prenatal stressors and infant HRV measures of both PNS and SNS over the first year of life.

Methods

During the third trimester of pregnancy, 233 women completed measures of life stressors and depression. At 1, 6 and 12 months of age, a stressor protocol was administered while infant electrocardiographic (ECG) data were collected from a baseline through a post-stressor period. HRV measures of PNS and SNS activity (HF, LF, LF/HF ratio) were generated from ECG data. We used multilevel regression to examine the aims, adjusting for maternal depression and neonatal morbidity.

Results

There were no associations between prenatal stressors and any baseline or reactivity HRV metric over the infant’s first year of life. However, exposure to more stressors was associated with lower post-stressor LF HRV at both 6 (β = −.44, p = .001) and 12 (β = −.37, p = .005) months of age.

Conclusions

Findings suggest potential alterations in development of the vagally mediated baroreflex function as a result of exposure to prenatal stressors, with implications for the infants’ ability to generate a resilient recovery in response to stressors.

Keywords:

• Stressors
• pregnancy
• fetal programming
• autonomic nervous system
• heart rate variability
• pregnancy
• infant

Acknowledgments

The authors are grateful to Sandra Niemann, PhD, for her contributions to project management and to both Sandra Niemann, PhD, and Nina Ahlers, MPH, for their contributions to data collection and data management.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author contributions

S. Weiss was responsible for project administration, funding acquisition, project conceptualization, design of the methodology, data analysis, and writing of the original draft. C. Leung contributed to project conceptualization, data collection, oversight and management of heart rate variability spectral analysis, and review of the manuscript. B. Cooper performed statistical analysis and reviewed the manuscript.

Additional information

Funding

This research was supported by a grant from the National Institutes of Health - Eunice Kennedy Shriver National Institute of Child Health and Human Development (R01 HD081188-05) to Sandra J. Weiss, University of California, San Francisco.

Notes on contributors

Sandra J. Weiss

Sandra J. Weiss, PhD, DNSc is a Professor and the Eschbach Endowed Chair in the Department of Community Health Systems at the University of California, San Francisco. Dr. Weiss studies: 1) women’s depression and stress, especially during pregnancy and the postpartum, and 2) biopsychosocial factors that shape fetal development of the nervous system and the microbiome as foundations for mental health in infancy and early childhood.

Bruce Cooper

Bruce Cooper, PhD is a biostatistician and data analyst in the Department of Community Health Systems at the University of California, San Francisco. Dr. Cooper has expertise in advanced statistical methods, including structural regression modeling, latent class analysis, and procedures involving complex longitudinal designs.

Cherry Leung

Cherry Leung, PhD, RN is an Associate Professor in the Department of Community Health Systems at the University of California, San Francisco. Dr. Leung’s research focuses on environmental and biological risk factors associated with infant, child, and adolescent mental health. She has a particular interest in the role of the gut microbiome in development and treatment of adolescent depression.