I am not sure what the question is here. There are lots of books on pregnancy exercising. No hi impact exercising, and after 20 weeks, stay off your back.
Free weights are ok as is circuit training, primarily focusing on upper and lower body.
If it is due to some kind of placental or growth problem, you should not be exercising. Hope this helps. These comments are for educational purposes only. They are not meant to take the place of an examination by a qualified health care provider. They are not intended to be the start of a physician-patient relationship.