The uterus can expand to, say, the size of a watermelon. The wonder organ, uterus, begins expanding from the day one starts conceiving. As per a few health reports during the first trimester it expands to the size of a grapefruit and by the second trimester it reaches the size of a papaya. It takes almost more than a month for the uterus to shrink back to its normal size after child birth.
