Physical activity and mood during pregnancy.

PURPOSE To compare three physical activity (PA) measures in pregnant women and examine mood correlates of physical activity changes during pregnancy. METHODS A sample of 12 pregnant women (PW) was recruited during their first trimester and 12 nonpregnant women (NPW) (baseline age = 30.7 +/- 4.4 yr) were matched to the PW (29.8 +/- 4.2 yr). Once monthly, for seven consecutive months, total weekly energy expenditure (TWEE) was assessed using a physical activity diary (PAD) and a recall interview (PAR). Accelerometers were worn for 3 d each month. Mood was also assessed. A two-factor mixed-model ANOVA was used to analyze the data (2 groups [PW vs NPW] x 7 times across pregnancy). RESULTS Mean PAR TWEE and daily mean MTI counts were positively and moderately correlated with mean PAD TWEE (PW: r = 0.40 and NPW: r = 0.50, P < 0.001). The MTI counts decreased significantly in PW by 23% from gestational weeks 12 to 36 compared with a 5% decrease in NPW. Fatigue and vigor scores improved from gestational weeks 12 to 16 and worsened from weeks 32 to 36 in PW. Changes in PA were not correlated to changes in mood in either group. CONCLUSIONS The results provide some evidence for the validity of the 7-d PAR and accelerometer as measures of physical activity in pregnancy. Healthy women who maintain an above average level of physical activity during the second and third trimesters can enjoy mood stability.