Related Experiment Video
Updated: Apr 30, 2026

Construction of Vapor Chambers Used to Expose Mice to Alcohol During the Equivalent of all Three Trimesters of Human Development
Published on: July 13, 2014
Disturbed dreaming during the third trimester of pregnancy
Jessica Lara-Carrasco1, Valérie Simard2, Kadia Saint-Onge1
1Center for Advanced Research in Sleep Medicine, Hôpital du Sacré-Coeur de Montréal, Québec, Canada; Department of Psychology, Université de Montréal, Québec, Canada.
Objective:
The majority of women develop sleep impairments during pregnancy, but alterations in dream experiences remain poorly understood. This study aimed to assess prospectively and comparatively the recall of dreaming and of disturbed dreaming in late pregnancy.
Methods:
Fifty-seven nulliparous, third-trimester pregnant women (mean age±SD, 28.7±4.06 years) and 59 non-pregnant controls (mean age±SD, 26.8±4.21 years) completed demographics and psychological questionnaires. A 14-day prospective home log assessed sleep and dream characteristics and the Sleep Disorders Questionnaire measured retrospective dream and disturbed dream recall.
Results:
Even though pregnant and non-pregnant women showed similar prospective dream recall (P=0.47), pregnant women reported prospectively more bad dreams (P=0.004). More pregnant women (21%) than non-pregnant women (7%) reported a nightmare incidence exceeding moderately severe pathology (>1/week) (P=0.03). Pregnant women also reported overall lower sleep quality (P=0.007) and more night awakenings (P=0.003). Higher prospective recall of bad dreams (r = -0.40, P=0.002) and nightmares (r = -0.32, P=0.001) both correlated with lower sleep quality in pregnant women.
Conclusions:
Late pregnancy is a period of markedly increased dysphoric dream imagery that may be a major contributor to impaired sleep at this time. Further polysomnographic assessments of pregnant women are needed to clarify relationships between sleep and disturbed dream production in this population.
Related Concept Videos
Nightmares and Night Terrors
Nightmares...
REM Sleep Behavior Disorder
RBD is significantly associated with...
Lucid Dreaming
Studies have shown...
Stages of Sleep
Before sleep begins, in wakefulness, the brain exhibits primarily beta waves, which are high in frequency and low in amplitude, indicating alertness...
Sleepwalking and Sleep Talking
Factors that increase the likelihood of sleepwalking include sleep deprivation and alcohol consumption. Contrary to common beliefs, it is safe...
Sleep-Wake Cycles
NREM Sleep
NREM sleep comprises four progressive stages that seamlessly merge:

