背景:多數孕婦因不確定適當的身體活動量而減少懷孕後的身體活動，且第三孕期身體活動對生產結果的影響性尚未明確。瞭解台灣懷孕婦女身體活動和體重管理對生產結果是重要的議題。目的:探討第三孕期身體活動、懷孕期母體體重增加量，對新生兒出生體重和孕產婦生產方式的影響性，及婦女懷孕前身體質量指數和新生兒出生體重的關係。方法:採前瞻性問卷調查法，在中部某醫學中心婦產科門診，收取懷孕28週後的健康婦女為研究對象共計123位，研究工具為孕期身體活動量表中文版，再於研究對象生產後，收集新生兒出生體重、生產方式及生產前最後一次產檢的體重資料。結果:懷孕期母體體重增加量為新生兒出生體重顯著的預測因子。第三孕期總身體活動量、身體活動強度和懷孕前身體質量指數，與新生兒出生體重無顯著相關。懷孕期體重增加量和總身體活動量，與生產方式亦無顯著相關，但孕婦的中度身體活動量每增加1MET-hour/週，陰道生產的勝算會增加1.017倍（COR = 1.014; p ＜ .05; AOR = 1.017; p ＜ .05）。結論／實務應用:懷孕期母體體重增加量、中度身體活動量與新生兒出生體重和生產方式相關，可做為孕期健康諮詢與身體活動指導的實證基礎。

Background: Most pregnant women tend to reduce physical activities during pregnancy because they are uncertain of the amount of moderate-level physical activity they should do. As the influence of physical activity during the third trimester remains unclear, it is important to clarify the pregnancy outcomes of physical activity during pregnancy and weight management among Taiwanese women. Purpose: To examine the potential association between physical activity during the third trimester of pregnancy and the birth weight or delivery mode of the baby in order to see whether weight gain during pregnancy affects birth weight and delivery mode and to estimate the associations between pre-pregnancy body mass index and birth weight. Methods: A prospective study was performed. Data were collected from 123 pregnant women, all between 28 and 40-weeks gestation, at a medical center in central Taiwan. The Chinese version of the ‘pregnancy physical activity questionnaire’ was used to collect data. Birth weight, delivery data, and the last weight measurement before delivery were retrieved from the medical records or via a postpartum telephone interview. Results: The results revealed that the amount of weight gained during pregnancy was a significant predictor of birth weight. Birth weight was not associated with pre-pregnancy body mass index or with physical activity and intensity of activity during the third trimester. Results provide no consistent evidence for an association between weight gain during pregnancy and the mode of delivery. Although no association was identified between total physical activity and delivery mode, the intensity of activity made a difference, with moderate-intensity activity of pregnant women increased 1 MET-hour/week. Thus, the odds of vaginal delivery over caesarean section increased by 1.017 times (COR =1.014; p ＜ .05; AOR = 1.017; p ＜ .05). Conclusions / Implications for Practice: The findings of the present study indicate that weight gain during pregnancy and moderate-intensity activity are both associated with birth weight and delivery mode. These findings provide evidence that health counseling during pregnancy as well as offering physical activity guidance may be done using a more empirical research base.