Daily maternal physical activity will be assessed in the week following these tests using the ActiGraph GT3X+ accelerometer (ActiGraph LLC, Pensacola, FL) in order to objectively measure daily physical activity levels. ActiGraph data will be collected for seven consecutive days on the non-dominant wrist at 30 Hertz. Time spent in sedentary and active (light, lifestyle, moderate, vigorous, and very vigorous) activities will be calculated using algorithms from Freedson and colleagues using ActiGraph software (Freedson 1998). We will also measurement maternal physical activity levels subjectively using the Pregnancy Physical Activity Questionnaire (PPAQ). The PPAQ is a valid and reliable instrument to measure physical activity levels during pregnancy (Chasan-Taber 2011). Not only will the PPAQ provide us with additional details about their activity levels, but it will allow us to account for activities that the actigraph may be unable to detect (i.e. riding a stationary bicycle).