Leg compression good. In general leg compression is an excellent idea during pregnancy. For this purpose, it may be better to get medical grade lower extremity compression garments rather than commercially available garments which come in limited sizes.
Too constricting :)! These undergarments maybe too constricting to be comfortable during pregnancy. It is important that you are comfortable and that nothing tight is across the belly. You may be able to find similar undergarments that leave room for your growing belly. Be sure to avoid clothing that can disrupt circulation.