Activity patterns and time allocation during pregnancy: a longitudinal study of British women.
OBJECTIVE
Few studies provide data regarding the integrated everyday activities of Western pregnant women. The study aimed to quantify changes in the daily activity of women during pregnancy and to examine whether pregnancy has a differential impact on different activity domains.


DESIGN
A prospective, longitudinal study of maternal time allocation and activity was carried out.


METHODS
The time allocation patterns of 57 healthy nulliparous pregnant women were assessed at 16, 25, 34 and 38 weeks gestation by semi-structured interview. Mean total daily activity levels (DALs) were estimated according to the intensity and duration of each activity reported. Self-reported activity was sub-divided into occupational, recreational, domestic and nocturnal activity ratios.


RESULTS
From 16 to 34 weeks gestation mean self-reported DAL declined significantly from 1.54 to 1.40 METS (Metabolic Equivalent TEE Score, where TEE is total energy expenditure) (p < 0.001). In the different activity domains, mean occupational activity ratio decreased (p < 0.002) whilst nocturnal activity ratio increased (p < 0.002) from 16 to 34 weeks. Mean recreational activity ratio decreased significantly between 25 and 38 weeks (p < 0.001) but no significant changes were observed in mean domestic activity ratio.


CONCLUSIONS
Low-risk pregnancy has a differential impact on occupational, recreational and domestic domains. Economies in energy expenditure appear to be made in occupational and recreational activity while domestic activities are largely maintained during pregnancy. Changes in physical activity may be influenced more by the type of activity rather than the intensity of activity.