Effects of Prenatal Nicotine Exposure on Short-Term and Long-Term Memory: A Literature Review

Abstract

Introduction: Maternal smoking impacts the health of both the mother and the baby. During gestation, nicotine can pass through the maternal-fetal blood interface in the placenta, accumulating in the fetal circulation and amniotic fluid. Because nicotine is a teratogenic agent, it can affect the development of the structures and functions in the brain of the fetus. Short-term and long-term memory are two areas of cognitive function that are affected. This literature review seeks to understand how prenatal nicotine exposure affects short-term and long-term memory, and how these effects will present in exposed individuals.

Methods: An extensive literature search was performed to find pre-clinical trials, clinical trials, and reviews on the effects of prenatal nicotine exposure on memory. The databases used for the search were PubMed, CINHL, and EMBASE. After removing duplicates and studies that did not meet inclusion criteria, 17 studies remained.

Results: 8 preclinical studies, 2 clinical studies, and 7 reviews that met inclusion criteria were included in this review. These studies found that exposed participants did not perform as well in memory and learning tests as compared to non-exposed control participants. Decreased integrity of structures in the brain, decreased function and size of neuronal structures, and low birth weight were noted in exposed subjects in multiple studies.

Discussion: Prenatal nicotine exposure impairs short-term and long-term memory by altering the development of structures and processes in the brain such as the hippocampus, prefrontal cortex, blood-brain barrier, cerebellum, and cholinergic functioning. Placental dysfunction associated with prenatal nicotine exposure can cause abnormal development of the brain and cerebral vasculature due to chronic hypoxia and fetal growth restriction. Due to the abnormal development of crucial systems used in short-term and long-term memory function, memory and learning deficits can be observed in adolescence and adulthood of individuals exposed to prenatal nicotine.

Conclusion: Information summarized in this literature review can be used to conduct future research and aid in public education on the negative effects of maternal smoking. Therapeutic strategies to lessen the effects of cognitive issues faced by individuals prenatally exposed to nicotine can be derived from future research on this subject.