Sleep, physical activity, and pregnancy symptoms: Factors associated with cognitive performance in early pregnancy.

Background: Women often report disruptions in cognitive performance during pregnancy. Though substantiated by objective assessments, findings have been inconsistent and potential contributing factors are not well understood.

Aim: The objective of this study was to examine the cross-sectional associations between maternal mood, stress, pregnancy-related symptoms and device measured 24-hour activity behaviors with cognitive performance in the first trimester of pregnancy.

Methods: Pregnant women (N=90) were assessed in the first trimester. Non-pregnant controls (N=73) were assessed 1-5 years after pregnancy. Depressive symptoms, (Center for Epidemiological Studies Depression Scale), stress (Perceived Stress Scale), and pregnancy-specific health related quality of life (Nausea and Vomiting during Pregnancy Health-Related Quality of Life) were evaluated using validated questionnaires, and 24-hour activity measured via actigraphy (activPAL, Actiwatch Spectrum Plus). Cognitive performance was evaluated using tests of memory, processing speed, and executive function.

Findings: Pregnant women performed lower on memory tests compared with non-pregnant women. Neither depressive symptoms nor stress were associated with lower cognitive performance in pregnancy. Physical symptoms of pregnancy (e.g., nausea, vomiting) were related to lower memory scores (β=0.32, P=0.02). Longer sleep duration was associated with better executive function performance (β=1.4, P=0.03).

Conclusion: This study demonstrates lower memory performance in the first trimester of pregnancy compared with non-pregnant controls and indicates that pregnancy symptoms and shorter sleep duration may be contributing factors.