The Role of Maternal Smoking in Sudden Fetal and Infant Death Pathogenesis.

Nadja Bednarczuk,Anthony Milner,Anne Greenough

doi:10.3389/fneur.2020.586068

Abstract

Maternal smoking is a risk factor for both sudden infant death syndrome (SIDS) and sudden intrauterine unexplained death syndrome (SIUDS). Both SIDS and SIUDS are more frequently observed in infants of smoking mothers. The global prevalence of smoking during pregnancy is 1.7% and up to 8.1% of women in Europe smoke during pregnancy and worldwide 250 million women smoke during pregnancy. Infants born to mothers who smoke have an abnormal response to hypoxia and hypercarbia and they also have reduced arousal responses. The harmful effects of tobacco smoke are mainly mediated by release of carbon monoxide and nicotine. Nicotine can enter the fetal circulation and affect multiple developing organs including the lungs, adrenal glands and the brain. Abnormalities in brainstem nuclei crucial to respiratory control, the cerebral cortex and the autonomic nervous system have been demonstrated. In addition, hypodevelopment of the intermediolateral nucleus in the spinal cord has been reported. It initiates episodic respiratory movements that facilitate lung development. Furthermore, abnormal maturation and transmitter levels in the carotid bodies have been described which would make infants more vulnerable to hypoxic challenges. Unfortunately, smoking cessation programs do not appear to have significantly reduced the number of pregnant women who smoke.

Highlights

Sudden intrauterine unexplained death syndrome (SIUDS) is defined as the “sudden death of a fetus after the twenty-fifth week of gestation and sudden infant death syndrome (SIDS) the sudden death of an infant under the age of 1 year, which is unexplained following thorough examination of the clinical case, history, death scene and autopsy [1]
Maternal smoking is a modifiable risk factor as both SIDS and sudden intrauterine unexplained death syndrome (SIUDS) are more frequently observed in infants of smoking mothers [7, 11]
Tobacco smoke contains a variety of hazardous components, but its harmful effects are mainly mediated by the release of carbon monoxide and nicotine

Summary

INTRODUCTION

Sudden intrauterine unexplained death syndrome (SIUDS) is defined as the “sudden death of a fetus after the twenty-fifth week of gestation and sudden infant death syndrome (SIDS) the sudden death of an infant under the age of 1 year, which is unexplained following thorough examination of the clinical case, history, death scene and autopsy [1]. Maternal Smoking, Fetal and Infant Death nervous system abnormalities and failure of arousal from sleep [7, 9, 10]. Maternal smoking is a modifiable risk factor as both SIDS and SIUDS are more frequently observed in infants of smoking mothers [7, 11]. A nationwide survey in New Zealand demonstrated smoking in pregnancy and/or bed sharing were the most important risk factors for sudden unexplained infant death regardless of ethnicity [12]. 22% of sudden unexplained infant deaths in the United States of America can be attributed directly to maternal smoking in pregnancy [14]. The aim of this review was to highlight the role of maternal smoking in the pathogenesis of sudden fetal or infant death. We have examined the literature to identify the mechanisms by which smoking in pregnancy could cause harm and the functional and structural abnormalities

PHYSIOLOGICAL ABNORMALITIES IN INFANTS OF MOTHERS WHO SMOKED

MECHANISM OF HARM CAUSED BY MATERNAL SMOKING

EFFECTS ON THE RESPIRATORY SYSTEM

FURTHER CONSIDERATIONS

Findings

CONTRIBUTION TO THE FIELD STATEMENT