Pregnancy hemorrhoids can be caused by hormonal changes to the digestive system. The increased blood flow in the area around the uterus and the pelvis because of the weight of the uterus, can cause a blockage of circulation.
Hemorrhoids or Piles can worsen towards the end of pregnancy. They may also get worse with each pregnancy you have. However they SHOULD ease away after delivery of your child. Check out the site below for more info.