孕妇的前额、眉间、颊部、鼻、上唇常长有黑花,尤其鼻梁上的那片,远看就象一只黑蝴蝶,人们都叫它“黑蝴蝶”或“蝴蝶斑”。这种淡褐色或暗褐色的色素斑在脸上呈蝶状,在医学上称为“黄褐斑”。 “黑蝴蝶”常常在怀孕三至五个月的时候出现,大部分在分娩之后就渐渐地消失了,再怀孕时还可能重复出现,并不属于病态,应该说是一种正常生理现象。发病原因主要是由于孕妇黄体酮及雌性激素的增加。因为黄体酮可以促使色素沉着的发展;雌激素可以刺激黑色素细胞,使皮肤出现色素斑。有人通过豚 Pregnant women forehead, eyebrows, cheeks, nose, lip often grow black flowers, especially the piece on the bridge of the nose, far looks like a black butterfly, people call it “black butterfly” or “butterfly spot ”. This pale brown or dark brown pigmented patch on the face is called “melasma” medically. “Black Butterfly ” often appear when pregnant three to five months, most of them gradually disappear after delivery, and then may also be repeated when pregnant, does not belong to the pathological, it should be said is a normal physiological phenomenon . The main cause of the disease is due to increased progesterone and estrogen in pregnant women. Because progesterone can promote the development of pigmentation; estrogen can stimulate melanocytes, the skin pigmentation. Someone through the dolphin