This discoloration is similar to what some women experience when taking the Pill. In the third trimester, because of fluid retention, the nerves snaking through tiny passageways are likely to be pinched by swollen tissue, which can lead to, or worsen, carpel tunnel. Occasionally, the shooting pain, numbness, and tingling can migrate to the forearm and shoulder. As veins enlarge to accommodate greater blood volume, and capillaries branch out to handle the increase, the skin all over your body enjoys greater blood flow. Progesterone reprograms the brain so that you'll inhale 30 to 40 percent deeper to supply all that extra blood with oxygen.
Some women even add inches to their rib cage as a result of increased lung size.
Your bones change in proportion to the tissue you have to support. On the other hand, many pregnant women continue to feel breathless even though they're getting plenty of air, partly because the baby is transferring more carbon dioxide to you. In the last trimester, breathlessness occurs because the growing uterus limits lung space. Digestion slows, letting food sit longer and creating more acid in your stomach. At the same time, this effect loosens control of the esophagus, which separates the stomach and throat.