There is a syndrome that only pregnant women get called Pruritic urticarial papules and plaques of pregnancy (PUPPP). Women with PUPPP develop small red bumps and hives, and when severe, the bumps form large patches. This rash usually starts on the abdomen and spreads to the thighs, buttocks, breasts, and arms. Alot of it has to do with the mother being almost allergic to their baby or its' placenta. Toxemia and other factors cause the rash and edema (swelling). The rashes can start on any part of your body but eventually get worse on the tummy and thighs. Another part of PUPPP is edema, which is swelling, most women get the swelling in their feet but with people who get PUPPP, you get massive swelling in every part of your body. I was so swollen with fluid when I went to give birth to my twin babies, that the epidural cathedar would not stay in my back, so I had to deliver all natural. PUPPP is very rare any usually occurs with women in their first pregnancy (but it can happen in any pregnancy) and with women who are pregnant with boys. It gets worse during the third trimester and you get so itchy that nothing seems to help. I recieved shots of visterol and used betamethasone ointment to help with the itching but the only way to relieve it all is to deliver the baby. Then most drs will have you on an IV drip of magnesium sulfate ( i was on this for 2 months to prevent premature labor) usually 24 hours after deliver to reduce edema and controll blood pressure. I hope you dont have PUPPP but its definately something to look into.