OBJECTIVE:To determine the level of moderate-to-vigorous physical activities (MVPA) and its relationship with gestational weight gains (GWG) in the second and the last trimesters of pregnancy.
METHODS:A prospective study was conducted in Chengdu on 362 healthy pregnant women at the 24-28 gestation weeks who delivered a singleton. Demographic data and pre-pregnancy body mass were collected using a questionnaire. Weight gains at the gestation weeks of 24-28 and 32-36 were measured for the first two trimesters and the last trimester of pregnancy. The Denmark self-reported physical activity scale was used for measuring the duration and intensity of physical activities. Multiple linear regression models were established to determine the relationship between MVPA and GWG.
RESULTS:The last trimester had lower average daily MVPA 〔(0.76±0.93) h〕 compared with the second trimester 〔(1.61±1.61) h, t=9.056, P<0.001〕. About 74.6% of the participants met the PA recommendations for the second trimester, compared with 60.5% for the last trimester (χ2=16.387, P<0.001). The participants experienced an average GWG of (7.36±3.78) kg during the first two trimesters, and (5.80±2.57) kg during the last trimester, corresponding to a growth rate of (0.30±0.15) kg/week for the first two trimesters and (0.51±0.22) kg/week for the last trimester. Compared with the most inactive group, the participants with medium PA experienced less GWG 〔(5.34±2.91) kg vs.(6.26±2.54) kg, P<0.05〕 and a lower GWG rate 〔(0.48±0.26) kg/week vs.(0.56±0.20) kg/week, P<0.05〕 during the last trimester. Age, gestational week, ethnicity, pre-pregnant BMI, GDM, pre-pregnant smoking and employment were associated with GWG and the GWG rates during the first two trimesters and the third trimester (P<0.05). Compared with the most inactive group, low 〔-0.358(-0.691--0.026)〕 and medium 〔-0.762(-1.486- -0.037)〕 PA were associated with lower GWG during the last trimester. Moderate PA was associated with a lower GWG rate 〔-0.071(-0.133--0.008)〕 after adjustment for gestational age, energy intake, pre-pregnancy BMI and other potential confounders.
CONCLUSIONS:Insufficient physical activities are a serious problem in the pregnant women of Chengdu over the last two trimesters. Appropriate MVPA in the last trimester of pregnancy may reduce GWG and GWG rates.