How much does the uterus grow during pregnancy?

The uterus grows from an organ that weighs 70 g with a cavity space of about 1 mL to an organ that weighs more than 1000 g that can accumulate a fluid area of almost 20 L. The shape also evolves during pregnancy from the original pearlike shape to a more round form, and it is almost a sphere by the early third trimester. By full term, the uterus becomes ovoid. The uterus is completely palpable in the abdomen (not just by pelvic examination) at about 12-14 weeks' gestation. After 20 weeks' gestation, most women begin to appear pregnant upon visual examination.

Source: http://emedicine.medscape.com/