Do atleast 15 minutes in the morning and half to one hour in the evening. Always sit on the floor . Avoid sitting on chairs. Every time you sit and get up from the floor is a good exercise for the uterine muscles. However one should be careful not to lose balance and fall down while doing this.
Some yoga exercises are good.
Those that for the hands and legs are good. This is an excellent simple exercise to have normal delivery. Do this after 4th Month of pregnancy till the labor day. Horse always does this mudhra, if one observes its anus. To do this specific exercise to anal muscles, hold and release the anal muscles.