Great way to get a good workout and work on those postural muscles. 
I recommend using these bands as well as doing Pilates or Yoga during pregnancy as they are so effective and low impact. 
Getting better control of your pelvic floor, breathing and glut muscles will tremendously help you through labour. 
 
Note: We cut those bands in the clinic to keep the prices affordable to you, so you might notice a slight uneven cut on the edges.