Hello Beth. It can be really serious situation especially when someone is pregnant.
We all do know that during pregnancy body undergoes many changes, and changes to your circulatory system are no exception. Now, if your circulatory system does not operate properly during pregnancy it can result in poor circulation. Also, this can cause so many other issues or it can even defect in your placenta or umbilical cord.
It is dangerous and really pointless to tell what somebody should do in this case.
There are several things that everyone can recommend - for example, sleeping at one side of your body, but that is a really small thing that you can do.