At 10 weeks, a pregnant woman's uterus is roughly the size of a grapefruit. Externally, the abdomen is unlikely to show visible signs of pregnancy, but clothes may feel tighter and less comfortable in the waist.
The uterus starts out approximately the size of a fist. By the end of pregnancy, the uterus fills the pelvis and most of the abdomen, pushing all other organs out of the way. Growth during pregnancy differs greatly from woman to woman, so healthy growth is measured in terms of personal progression rather than in accordance with a standard size. In tracking growth, doctors measure the top of the uterus in relation to the rest of the woman's anatomy.