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

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.

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.

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.

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).

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.