The function of the uterus is to accept the fertilized ovum which will turn into a fetus and hold it during development; it also helps support the fetus during the gestation period. The uterus is the site where the fertilized egg is implanted for gestation.
Once the egg is implanted, the uterus provides nutrition for the fetus — that is embedded in the endometrium — through blood vessels that are developed specifically for this purpose. The human uterus weighs approximately 2.2 pounds, or 1 kilogram. This weight stays the same even during pregnancy. The weight of the uterus doesn't change, but it stretches and changes as needed during the gestation period.