Haemorrhage make a fresh start is unripe period begin ( hilum bleeds ) , but great majority is controlled in 2 years old , as the grow in quantity of development activity , haemorrhage tendency fadein is written 出血自新生兒期開始(臍出血) ,但大多數(shù)在2歲左右,隨著發(fā)育活動(dòng)的增多,出血傾向漸顯著。