For most pregnant women, being comfortable and getting enough rest can be two of the biggest challenges. Typically, these problems affect more than 75 percent of pregnant women. During the second and third trimesters (20 weeks and beyond), lower back pain and stomach discomfort often increase.Women who normally sleep on their back or stomach often find getting enough restful sleep especially challenging. Sleeping on the back is discouraged because of compression of the uterus on the large blood vessels (inferior vena cava) and on the intestines, causing decreased blood flow and oxygen to the baby. Some Tips on Improving Your Sleep. Set the proper mood to prepare for sleep through soft lighting, a good book, a warm bath (try adding a small amount of lavender oil) and/or a warm non-caffeinated beverage. Experiment to see what helps you unwind. Massage by your wife is also a good way to relax. Try daily exercise - walking or pregnancy aerobics often help. Use comfort aids, such as the Gen