REM sleep alteration and depression

Sleep Quality and Associated Factors among Pregnant Women Attending Antenatal Care Unit at the Referral Hospitals in Oromia National Regional State, Ethiopia, 2021: A Multicenter Cross-Sectional Study

INTRODUCTION

Poor sleep quality during pregnancy leads to adverse neonatal outcomes such as low birth weight, intrauterine growth retardation, preterm birth, and operative birth. Though it has many consequences, a limited study was conducted on the prevalence and associated factors of poor sleep quality among pregnant women in Ethiopia.

OBJECTIVE

This study is aimed to determine poor sleep quality and associated factors among pregnant women attending antenatal care units at the selected referral hospitals.

METHODS

Institution-based cross-sectional study was used from April 20 to June 10, 2021. A The data were collected through systematic random sampling. The Pittsburgh Sleep Quality Index (PSQI) was used to assess the outcome variable based on interview.

RESULTS

Out of 423, almost 414 participated in the study with a response rate of 97.9%. The prevalence of poor sleep quality was 54.6% (95% CI: 49.7%, 59%). Based on the trimester; about 44.8%, 36.8%, and 64.2% were observed poor sleep quality in the first, second, and third trimesters, respectively. Third trimester [AOR (Adjusted Odd Ratio) = 4.33; 95% CI (Confidence Interval) (1.43, 13.7)], primigravida [AOR = 4.03; 95% CI (2.59, 7.97)], para ≥2 [AOR = 1.95: 95% CI (1.09, 3.48)], depression [AOR = 4.59: 95% CI (2.31, 9.15)], and perceived stress [AOR = 1.15: 95% CI (1.1, 1.22)] were factors significantly associated.

CONCLUSION

One in every two pregnant women has poor sleep quality. Depression, perceived stress, gestational age, gravida, and parity were identified as associated factors with poor sleep quality. Therefore, healthcare providers should work on screening and counseling for sleep problems during prenatal checkups.

The role of REM sleep theta activity in emotional memory

While non-REM (NREM) sleep has been strongly implicated in the reactivation and consolidation of memory traces, the role of rapid-eye movement (REM) sleep remains unclear. A growing body of research on humans and animals provide behavioral evidence for a role of REM sleep in the strengthening and modulation of emotional memories. Theta activity-which describes low frequency oscillations in the local field potential within the hippocampus, amygdala and neocortex-is a prominent feature of both wake and REM sleep in humans and rodents. Theta coherence between the hippocampus and amygdala drives large-scale pontine-geniculo-occipital (PGO) waves, the density of which predicts increases in plasticity-related gene expression. This could potentially facilitate the processing of emotional memory traces within the hippocampus during REM sleep. Further, the timing of hippocampal activity in relation to theta phase is vital in determining subsequent potentiation of neuronal activity. This could allow the emotionally modulated strengthening of novel and gradual weakening of consolidated hippocampal memory traces during REM sleep. Hippocampal theta activity is also correlated with REM sleep levels of achetylcholine - which is thought to reduce hippocampal inputs in the neocortex. The additional low levels of noradrenaline during REM sleep, which facilitate feedback within the neocortex, could allow the integration of novel memory traces previously consolidated during NREM sleep. We therefore propose that REM sleep mediates the prioritized processing of emotional memories within the hippocampus, the integration of previously consolidated memory traces within the neocortex, as well as the disengagement of consolidated neocortical memory traces from the hippocampus.