How is the excretory system affected by pregnancy?

There is frequency and urgency in first trimester of pregnancy and later on slight Hydronephrosis in later months of pregnancy, due to pressure on Ureters.(Two tubes, each tube coming from pair of Kidney to the Urinary bladder and lies on the back side of abdominal cavity and feel the Bladder drop by drop.) Witch eventually get reverted. And the family is rewarded with the most beautiful gift it can ever have, a BABY.