[The Relationship Among Physical Activity During the Third Trimester, Maternal Pre-Pregnancy Body Mass Index, Gestational Weight Gain, and Pregnancy Outcomes].

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.